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Vorshlag 2018 Mustang GT + S550 Development Thread

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Vorshlag Shop car / S550 Development Thread Introduction - October 23rd, 2014: This thread is where we talk about our testing, shop work, parts development, and racing with S550 Mustangs. We will use this thread to share weights, pictures, and tech of various S550 Mustang parts and cars we work on. I started this thread in 2014 when this chassis was just arriving, and in February 2018 our shop bought a 2018 Mustang GT, which we are now using for more hands-on testing. We will use this shop car for development instead of just relying on outside testers' cars, and I have re-written this intro to reflect the change in direction for this thread.


This forum thread was started in 2014 just on our little forum, but when I revived it in 2018 we cross-posted it to some other forums we sponsor (or that allow us to post there), after we bought our red 2018 GT. Getting this car after the '18 major sheet metal facelift and new Direct Injected 5.0L engine made it seem more relevant now, and I'm glad we waited. Automotive forums are declining, but we feel these are much better places to share data and a better long-term repository for tech than social media (where everything posted is wiped out in about 48 hours), so that's why we go to the effort. We will be updating this thread on the following forums:

We will try to answer every question in this thread on all forums we have cross-posted on, so feel free to ask or comment about anything you see. Please keep your comments to S550 related things that "we would know" (we are not a basic repair shop, body shop, EFI tuner, or stereo/bling shop - we specialize in suspension, wheels/tires, brakes, safety gear, aero, and chassis work). You can always call or email us at Vorshlag, too.

Autocrossing and tracking this car on the skinny stock 235mm all season tires was hilarious!

We did both a track test and autocross (above) in the first week of ownership, in bone stock form, and it was pretty terrible. The next week we upgrade the base model GT with 11" wide wheels/tires, aftermarket monotube adjustable coilovers, plus our front camber/caster plates and spherical Rear Shock Mounts.

That's more like how a Mustang should look...! 19x11" Forgestars and 305 Bridgestones

As always, any picture you see can be clicked for higher resolution versions. Videos are almost always linked to our YouTube channel, for best results there. As you might know we weigh everything - and that is what prompted the start of this thread in October 2018, when we started weighing these S550 cars.

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Stay tuned as we add more S550 content to this thread, from work we have done over the last 4 years as well as new development we tackle using our shop 2018 GT and other testers' and customers' cars.


At long last an S550 Performance Pack 6-speed GT finally arrived in Dallas. Not the one we ordered, but a stocking order GT with similar performance equipment. This one has power leather seats (not the leather Recarcos) with Sat Nav, 12 speaker stereo, the bigger 15" 6-piston brakes, the 19x9/19x9.5" wheels, the works. All the goodies, probably the heaviest way to get an S550 other than convertible automatic GT (yuck!)


You have all seen the "magazine" weights thrown around, and like usual, the numbers are bunk. I swear these writers don't know how to work a set of scales. ;) We see this every time a new model comes out - either they weigh a car with a full tank of fuel, or two people inside, or lead weights in the trunk, or just parrot the marketing materials they were given. Can they just plain dyno and weigh a car for us gearheads, PLEASE??

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Corey White of Five Star Ford of Plano gave me a heads up that their very first 2015 Mustang had arrived earlier today. It was the FIRST GT 5.0 Performance Package car he knows of in Dallas, as there was a production delay on these cars due to some changes to the placement of the catalysts.

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This 2013 GT is caged and has all the W2W safety gear. With one seat it is almost 3300 even

After finishing up with a customer's delivery of his race-prepped 2013 GT (built for NASA ST3, see above on the scales) we loaded up our brand new wireless Intercomp digital scales and rushed over to Five Star Ford to get that pony weighed. Why? Because I'm always a skeptic about almost ALL data on cars, and only believe what I can measure on real scales, first hand.


Turns out this thing is about 100 pounds lighter than all of the numbers the magazines had been throwing around. 3718 pounds with low fuel - low fuel levels are easier to compare between cars and is often how we race these cars in Autocross or Time Trial (depending on fuel tank/pick-up). This weight is with the "Trunk Junk" removed, which includes the floor mats, trunk mat, and the emergency tire inflation kit (no optional spare tire).

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Trunk junk came to 13 pounds, and there's likely another 15-20 pounds in the trunk mounted sub-woofer. It is removable but they asked me NOT to take it out, since this car is their very first 2015 and going right on the showroom today. After we weighed the car, Corey White (the salesman in the pics, and a real gear head) told me to hop in and we drove to their fuel pumps to put a splash of 93 in the tank. Then he hopped out and said, "You're driving!" How could I say no?

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We went on about a 15 minute test drive, re-striping the streets of Plano in Pirelli rubber. ;) The car drives REALLY well, rides very similarly to a CTS-V... good compression damping, firm but supple ride on the choppy concrete roads, and hauls ass when you give it the Go pedal. Motor feels strong for a zero mile car with similar acceleration to the 2011-14 GT or Boss 302. The PP cars all have the 3.73 gears and Torsen axle. The sticker price is shown below.

As always you can click any picture for a larger rez version

The ergonomics are spot on. I've sat in a couple of these but driving it was amazing. 6'7" Corey fits in here well, and my 6'3" frame was swallowed up with ease as well. The shifter feels GREAT and the lever is right where my arm wanted it. The steering wheel has a big FAT rim and gauges that were easy to read. The seats were good, but the Recaros are better - that option worth the extra coin, if you never plan on installing real racing seats.

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Loved the switch gear, and the materials + leathers were top notch. Pedal spacing was perfect for heel-toe downshifts. Just a quick street drive but I really liked it.

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Left: 2014 Camaro Z/28 with A/C and 3/4 tank, sans trunk junk = 3835 lbs. Right: 2011 GT Brembo Premium 6-spd, sans trunk junk = 3563 lbs

Closing thoughts: this car will be a hot seller. We happened to weigh a 2014 Camaro Z/28 today (equipped with A/C, see above) and it was 3835 pounds with 3/4 tank of fuel. So the S550 is considerably lighter, which is good news. I was pretty upset after hearing the (bogus) 3850+ pound numbers being thrown all over the internet for the S550, and had essentially given up on these cars before they even arrived. That was probably a bit rash, and now I am back on the Pro-S550 bandwagon.

Since we introduced them in 2014, our S550 camber/caster plates have been a huge seller

Look for products for this chassis coming from Vorshlag soon - and don't worry, we're going to keep supporting the S197 Mustang even after our 2011 GT is sold (edit: it was sold in 2015). The dyno numbers for the S550 look promising, and the exhaust gains seem pretty big for simple work. The wheel/tire packages on these cars are SUPER heavy - we have a Forgestar CF5 18x10 that fits this car, plus 18x11" wheels in the works, and there's even more "extra weight" in the exhaust and wheels. We will try to get some weight out where we can...

Thanks for reading,

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Vorshlag Shop car / S550 Development Thread Introduction - October 23rd, 2014: This thread is where we talk about our testing, shop work, parts development, and racing with S550 Mustangs. We will use

continued from above With no lap time I had to slip into the first open spot on grid for the non-timed cars who missed the warm up, which was 34th! We had 51 TT entries this weekend, so it was a bit

continued from above In that first Sunday session I ran my best of the weekend with a 2:32.930. I was almost ten seconds slower the TT3 winner that day, my friend Paul Costas driving the cheateringes

Thread Update for September 12th, 2016: Long time no update here, but we have been busy with S550 development. In this update we will show two camber plate designs we made for this chassis, plus wheels/tires and MCS coilovers we developed in early 2015.


Aaron's 2015 GT PP was weighed in stock form, with the trunk junk removed, at 3678 lbs (1/4 tank)

Shortly after Aaron Sockwell got his 2015 Mustang GT PP (May 2015), we borrowed it and took a number of measurements. He worked at a shop across town that competed at the same Optima events as us, and he had the first S550 locally that would be competitively run in their autocross and time trial events.

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Above: The factory "Performance Pack" wheels are 19x9" front and 19x9.5" rear, but they can fit more...

We measured for wheels, MCS coilover shocks, and more. To measure for wheels we started with the stock GT Performance Pack 1 parts he had - pulled them off and of course weighed the wheels and tires (above). We used some other wheels we had on hand to help determine what we thought could fit this S550.

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As always we were going for MAXIMUM width under stock fenders without significant modifications. We found out after years of testing on our similar weight/power/sized S197 Mustang GT that the more tire width you can run, the better. How wide? "As wide as they make!" - but on this car, he didn't want to cut the fenders, at first. So 315mm width tires was our goal, front and rear. That tire width needs a 11" wide wheel, but many of our customers want a "rotatable" set so we use a 10" wide wheel, which fits front and rear (shown above at right). The S550 needs different offsets for both the 10" and 11" wide wheels than the S197 chassis, and it also uses a different lug stud size (M14) than the older model.


The Forgestar CF5 wheels above are what we ended up with, in 18x11" size. These fit the S550 under the stock fenders with a 315/30/18 tire (he started with Falkens and moved to BFG Rivals) as shown, with some added camber up front. Its a tricky setup, and there is VERY little room for error. Some wheel makers just "get it close enough" and tell you to run a spacer for this width on these cars, but we have it down to the millimeter. The front and rear offsets are VERY different to fit this car, but that is what it takes to fit it.

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Our shop took apart the suspension then Shannon and Jason measured the stock shocks, mounting locations, and made a bunch of drawings for MCS out of Georgia. Those drawings were fired off to them and we put Aaron's car back together for the day.

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A couple of weeks later the shocks and wheels arrived, so then it was time for a camber plate design. We had the car for 2 days and in that 48 hours we measured, designed, programmed, machined, assembled and installed these camber-caster plates. It was a short deadline but Jason stepped up and got it done.


The prototype camber plates were installed onto the prototype MCS TT2 struts, shown above. These were installed along with a rear spring and MCS shock onto our tester's Aaron's Mustang, then it was on track 48 hours later  and racing in the Optima/USCA series. He has run these prototype plates for 2 seasons and the parts are still working perfectly on the 2nd owners' car.


These S550 camber plates were initially only available for "coilover spring" sizes, which the market wasn't ready for. It would take another tester to prompt us to make that version, the following year.


At the time in early 2015, MCS had the first "serious" monotube adjustable on the market, after working with Vorshlag to get this set on our tester's car. We didn't have a good rear spring solution at the time (we do now) but with the Eibach lowering spring in the stock location, and a stiffer 60mm spring up front, the car was fast.

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Since then we have moved to a coilover-rear spring, but I will show that in a future post. For certain racing classes where you have to use the spring in the stock location we have a ride height adjuster in the works for this car.


We had the TT2 set dyno'd and the shock dyno charts for the front struts and rear shocks are shown below. The red curves are at the least rebound or compression valving. The green is about mid-way up and the blue is at full stiff. Of course rebound and compression are independently adjustable on these 2 way non-remote MCS dampers. MCS makes S550 shocks in single adjustable (TT1: low speed rebound), 2 way non-remote (TT2:, low speed rebound, low speed compression), 2 way with remotes (RR2), and 3 way with remotes (RR3:, low speed rebound, low speed compression, and high speed compression).


We tend to avoid the 3 way option unless a customer is building a race car -and- they are very familiar with 3 way dampers. You can tune yourself into a bad place with too many adjustments. The dyno above shows the MCS TT2 fronts struts with damping force curves that can accommodate a large range of of spring rates without re-valving. Both rebound and compression curves are digressive - which allows for both aggressive track use and, when turned down, good ride for street use.


The MCS TT2 rear shocks are similar in their dyno shapes, ranges of damper forces, and adjustability. We tend to recommend these TT2 doubles for folks who are more serious about competition in autocross or track environments, that understand adjustable dampers, and don't want to spend the extra money on remote reservoirs. Remotes move the compression stack + the floating piston and Nitrogen chamber into the reservoir. This allows for more total damper travel in the same length shock as well as more heat shedding area and more total fluid. We recommend MCS remotes for dedicated race cars and Pro level teams.


The dampers and spring rates we picked for Aaron's 2015 GT really helped control the roll/dive/squat/heave of the very soft factory S550 chassis setup. Aaron raced his S550 for two years on the Optima Ultimate Street Car Circuit, with wins in the GT class and invites to the OUSCI shootout after SEMA. He moved to another shock brand sometime in his second year of competition, as well as wider 335mm tires, 18x12" wheels, and flares. Then he added a supercharger. Aaron sold the car soon after that so we lost our local S550 tester.


Shortly after the prototype set was built we made a production version of our S550 camber plate, shown below. This was still only compatible with the common coilover spring sizes: 2.25", 60mm, or 2.5". We make perches to fit any of those. But the problem was - the car was so new, people weren't ready for coilovers. They wanted to keep the stock shocks...

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Adding negative camber is one of the FIRST modifications racers do to their cars, and the S550 chassis needs it just like so many others. Brian Matteucci was an old friend from college and he bought a used 2015 GT PP 6-speed Mustang in 2016. We used his car to develop a new version of our S550 camber plate for use with the OEM style springs. Like a lot of you out there Brian didn't want coilovers - he had three other road race cars and the Mustang was only supposed to be a stop-gap car, a quick build. Brian just wanted to do a handful of changes to make the S550 autocross and track worthy, without spending a lot of money.


The 2015 GT above was the test mule for a new design of our S550 camber plate made to use the OEM style springs and stock shocks. He ended up running our 18x11" Forgestar wheel and a 315/30/18 BFGoodrich Rival-S tire. These cars need front camber to help fit that massive tire under the stock fenders, but it also needed the camber to keep from excessively wearing the tire's outer shoulder.

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The S550 camber plate for use with OEM springs (shown below) was a bit trickier to design, and we tackled this in early 2016. The OEM top mount / upper spring perch (above) made for a very short stack-up height, so we had to design some new parts and use a new bearing to make our parts match the factory height. Again, we want to neither raise nor lower a car with our camber plate + perch assembly when the stock springs are used.

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Similar to the S197 design, the S550 camber plate has variable camber adjustment that "slides" for another 2.5° of negative camber travel, as well as 2 fixed caster settings (stock and +1.0°). These plates also have more travel built into them than the stock strut tower will allow, but like the S197 design you can modify the tower opening for more usable range. We found that with OEM springs and stock ride heights you can still get to -2.5 to -2.8° camber on an S550 without touching the towers or going to coilovers - which is ideal for the weekend warrior, dual purpose track rat.

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We rated factory springs from the Shelby GT350 (left) and GT350R (right) in the charts above. We rated these at 1/2" increments on our digital spring rater. Many spring makers take the springs to coil bind, back them off a hair, and divide this load by the travel they reached - which leads to artificially high spring rates. We see this on almost every lowering spring on the market when we rate them what we consider "the right way", to get actually useful information.


Brian installed the GT350R springs, our prototype camber plates made for OEM style springs, and the 11" wide wheels and some stick 200 treadwear tires. He then immediately took this otherwise stock Mustang and beat 19 CAM-C cars at its first National level autocross event, then won the CAM ProSolo class a few weeks later. Negative camber helps even more on a road course.


This has been our best selling camber plate since it was introduced in late 2016. It seems to be the first mod S550 owners do if they autocross or track their cars.


Just like the 2015-up Mustang GT V8 and turbo 4 Ecoboost cars, the Shelby GT350 is a great car to use on track - and with more cooling, better brakes, and bigger tires and wheels from the factory they are that much further ahead. These Shelbys are still just as heavy as the GT, and likewise suffer from the same "lack of camber adjustments" problems. If you run these cars in bone stock trim on track be prepared to replace the front tires often...


In 2016 we started to get our hands on more and more of these GT350 Mustangs. We used the installation of a production set of Vorshlag S550 camber plates on the 2016 Shelby above to make this installation instruction gallery, which has been viewed hundreds of times since.


Take a look at that gallery to see step-by-step instructions and tips to help make the install of these OEM style camber plates trouble-free. This can be done at home with hand tools and a floor jack, but an impact tool is needed to tighten the strut top nut. See

for more explanation about that.

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One of our GT350 customer's had a right rear CV boot rip and let go, and it looked like a rash of them. They all show evidence of a tear in the boot possibly from the production line, so its likely not a design issue at all. Ford is fixing these all under warranty. We haven't seen this pop up again since late 2016.


I haven't posted many pictures of the GT350 cars we have worked on, but took the time in today to share some things. There are a number of improvements to the GT350/R that are well thought out, with a number of innovative solutions to little problems - some of which stem from the 5.2L 180° firing order crank. One thing that caught us as strange was the plastic oil pan, only found on the Shelby GT350/R models until the 2018 Mustang GT 5.0L got it as well (as a weight saving measure).


We talked to one of the lead engineers on the Shelby GT350 project and he said this and many other items were changed to deal with the added vibrations of this unusual crankshaft layout. There are primary and secondary harmonics that cause vibrations that make things want to rattle, loosen/unscrew (oil filters), and more. They were trying to tackle these "NVH" items up until the last minute before production started.


There are mass damper weights mounted all over the GT350 chassis. It is amazing how much effort they put into damping the vibrations of this unusual engine, but people love the way it sounds, and it is made to rev up to a higher RPM, which helps it eek out more power (526 hp) than the 2015-17 5.0L (435 hp) or the 2018 GT engine (460 hp). The higher powered Shelbys also get a stronger 6 speed manual, the Tremec 3160 (read more here).


Some Shelby owners had been asking us about the caliper mounting bolts, which are HUGE. They wondered if there was a way to add a stud in place of that instead, to keep from galling/stripping the thread in the caliper mounts on the spindle. I suspected that the closeness of the bolt head to the 19" stock wheel might prevent that, but it looks like somebody has figured out the trick.


Ford has been employing what we call the "scoop and flap" method of front brake cooling. This starts with a front scoop that dumps high pressure air via a vent (see above) into the wheel well area. This is something Porsche figured out in the 1980s and we see it on high performance cars all the time. It is nothing like ducted brake cooling, which is common for race cars - where they take high pressure air from an inlet and plumb it through flexible hose to the back of the rotor. But the scoop-and-flap is at least... something.


Normally there is a "flap" that is attached to a control arm that directs the air stream towards the hub and rotor. The regular Mustang GT has this but the GT350 does not. Yet the control arm has the mounting bosses for the flap. Did it get left off for a reason?


The front 15.5" diameter, 2-piece, pin drive aluminum/iron front brake rotors from the Shelby are quite large, and they weigh in at 30 pounds. This is lighter than the front 15" rotors from the GT's Performance Pack, shown below at 33.3 pounds. The Performance Pack was a $2500 option from 2015-2017 on the base model GT and included those front brakes with 6 piston calipers, and they are pretty dang good. The Shelby had to be BIGGER so they went 15.5 and 2-piece. ;)

2015-18 GT Performance Pack front rotors are a little smaller and a little heavier, but a lot cheaper to replace

While we worked on our first Shelby GT350 this week we took a number of other pictures with it in the air.

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Here are a couple of rear "underskirt" shots, showing some scoops leading to rear mounted coolers. We also measured axle width to the wheel mounting surfaces, just because.


This red GT350R (weights shown above) was out at the track with us a few weeks ago, when I was getting a baseline lap in our stock 2013 FR-S. We were at Motorsport Ranch Cresson (MSR-C) running their 1.7 mile CCW course. Pics are here.


The owner, Josh, hasn't done track events in a few years and just sold his Miata before getting into the GT350R. He drove in 3 thirty minute track sessions that day, hot and humid, and the cooling system did great. He ran a best of 1:25.22 but there was probably some time left in braking, as you might notice in the video above. Not trying to show a Stig lap here, just a regular guy making some fun laps in bone stock form on the stock tires. In the screenshot below and in the first lap of his

you can see him passing me in the FR-S like I dropped an anchor (I was wide open throttle there!)

Some reference times for the MSR-C 1.7 CCW course:
  • My quickest lap time in a street legal car here is a 1:17.25 from 2014 in our NASA TT3 classed 2011 Mustang GT on giant Hoosier A6 tires + aero.
  • TTC classed 1992 Corvette (gutted, prepped, but nearly stock in every way) was a 1:21.9 on 245 Hoosier R7s.
  • 1:27.6 the same day in our TTD classed BMW E46 330 (with cord showing on the 245 R7 tires).
  • Stock 2016 Focus RS to the best of a
    on the stock 235mm Michelin PSS tires.
  • 2015 VW GTI to a best of 1:28.10 on 225mm MPSS tires (stock but with our camber plates and a tune).
  • Stock 2013 FR-S to a
    on 320 treadwear 215mm tires.


So far I'm fairly impressed with both the GT350 and R models, and once the price gouging ends these should make for fairly good track cars. I am heading back to Cresson this Friday to run the Focus RS on a 275mm Bridgestone RE71R on custom 18x9.5" wheels, with coilovers and a big oil cooler. Will also drive some laps in a 2017 C7 Corvette Grand Sport that we are aligning and weighing today. If Josh is there in his GT350 and finds more time I will post up the laps here.


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Project Update for March 6th, 2018: I should lead with this bit of news first: Vorshlag bought a brand new 2018 Mustang GT two weeks ago! We're finally coming back into the Mustang market in a big way with our new S550 shop test mule.


We bought this car because the 2018 GT model has an exciting list of changes and upgrades that made it attractive to jump back into a new Mustang. The all-new 460 hp direct injected Coyote V8, new MT82-D4 6-speed manual transmission with a twin disc clutch, and of course the all new front bodywork, lighting, and other cosmetic updates. There are a ton of products we have wanted to develop for this 2015-up Mustang chassis, which we can finally do now. :)


In 2010 we ordered a 2011 Mustang GT. We used this test mule for extensive S197 product development for 5 years. The changes in the 2011 model were significant for the 2005-2014 S197 chassis - all new bodywork (2010), new brake options (14" 4 piston Brembo package), new transmission (MT82), and an all new motor (Coyote 5.0L) in 2011 that gained 100 hp from the previous 4.6L V8. It was a perfect time to get an S197... and Vorshlag has been known for S197 parts ever since then.

This 2011 GT won a lot of races, set 16 track records, and helped Vorshlag develop a lot of parts

Sure, the S550 chassis debuted in model year 2015, and we have done a good bit of product development on these cars since the beginning, but it has been difficult to find and keep some local "testers" to work with for long term testing and prototyping.

Our first S550 tester's 2015 GT (left) next to our shop S197 Mustang test mule (right)

Our first S550 test car was Aaron's 2015 GT PP, shown above at left. This car was borrowed in the first months of the S550 introduction to develop the first coilovers from MCS and our first S550 camber plate - which went from concept to CNC machined parts in 48 hours. We also used Aaron's S550 to help us come up with 10", 11", and even 12" wide wheels, which we have had built for us by Forgestar for this chassis since 2014.


We built 18x11" F14s for Aaron initially that he raced with in Optima series on a 315 Rival-S, and for the first year and a half of competition he used our prototype wheels, MCS shocks and camber plates. We have provided many many sets of wheels for S550 customers since. We also worked with G-LOC to come up their various S550 brake pad versions, which were also used on Aaron's 2015 GT. Aaron has since sold this car, so we lost our local S550 development tester.

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Our second S550 tester was Brian from Houston with his white 2015 GT PP above. We developed a brand new S550 camber plate revision that could work the OEM springs for both the GT and GT350 - it was a complicated engineering, but this version works VERY well for stock springs, and we have sold many hundreds of sets of these camber plates.

Aaron's 2015 GT PP in bone stock form, testing at ECR Dec 6, 2014

But beyond those first few handful of items for the S550 (MCS coilovers, Forgestar wheels, and two camber plate versions) we have been limited on what we could develop and sell for this chassis, due to a lack of local testers or an in-house test car for the last 2 years. People haven't been rushing to Vorshlag for other S550 parts we carry, because we aren't "known" for racing a S550. We are fixing that now.

Look at that front end rise! Me putting in Baseline Test Laps in in Aaron's 2015 GT at ECR, Dec 6, 2014

What did it was a ride along on track. I had only ever driven Aaron's 2015 GT in stock form at ECR back in 2014, but I rode in Brian's white car (now owned by his buddy, Matt) at a NASA event in October 2017 at MSR-Houston. After riding/coaching with Matt for a session I was pretty damned impressed with this S550 - it only had our camber plates, some 350R springs, a Torsion T2R, the 19x11" wheels we sourced, and some 305/30/18 Bridgestone RE71R tires. It was just flat out fast, put all the power down easily, gobbled up bumps and curbs like no Mustang I had ever driven, and woke me up to the reality of how good the S550 can be with a few tweaks.

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We are a little late to the S550 party, but this 460 hp direct injected 2018 Mustang GT is now part of our test fleet!

I started looking closer at the 2018 GTs last Fall when new cosmetic changes were introduced, just before the drivetrain upgrades were announced. The new motor having more power, the stronger twin disc clutch, the stronger version of the Getrag 6-speed manual with all new gearing and synchros (MT82-D4), and some other changes. I waited until this Spring until I drove one... we quickly found one with help from our friend Corey White at Roush and his compadre Rich at Five Star Ford in Plano. We bought the bare bones 2018 Mustang GT two weeks ago (above) and they made me keep it a secret - which nearly killed me. This car will be our in-house development mule for new S550 parts as well as our primary autocross and time trial car for the next few years.

First autocross was run on bone stock suspension, brakes, wheels and tires. It was hilarious!

So if you enjoyed the build thread and S197 development we did on our 2011 Mustang GT, buckle up because this S550 is likely going to be faster than that car. We are going to try to keep it streetable for at least the first 2 years, so it doesn't get too scary for some of you guys! :D


There are many reasons why we didn't buy an S550 when it first came out in 2014, and why we did now in 2018. I will go into that briefly below.

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"The one that got away" - the 2015 Mustang GT we almost bought

We did look at purchasing a 2015 GT in the Fall of 2014, shown above. The dealer even brought it by our shop to test drive, measure, and check out - it was perfect. Performance Pack (15" 6 piston brakes + bigger wheels/tires), leather Recaro seats, touch screen Nav, Race Red. Problem was the $43K price tag was a bit more than I could swallow at the time. We had just renovated and moved into a new shop space (which costs $$$), just got back from two weeks of the whole shop going to SEMA/Optima shootout in Vegas (which cost $$), just bought CNC machines ($$$$$!), and I was tapped out. Bad timing, but our dealer was happy to sell this car to someone else for more money - it was the "hot new car" with the perfect options and color. It was sold within 24 hours.

"The one that got away" - the 2015 Mustang GT we almost bought

I have second guessed this decision ever since - this was a perfect test car, right when the S550 was new and hot. Sure, we could have gone into more debt and made that purchase happen, and we would have surely developed a stronger S550 following by now. But moving CNC manufacturing in-house was a big necessity back then, and tooling up was  a giant time and money suck. We needed to concentrate on this aspect to keep growing our business.

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"The one that got away" - the 2015 Mustang GT we almost bought

3.5 years later its a whole different situation at Vorshlag. Our CNC operation is running smoothly and our reputation for having a backlog on suspension parts is long gone - because we did concentrate on the CNC aspects instead of buying another car. We are now way ahead on our inventory production, and have been developing new parts every month since. The business is growing and yet... I still wanted an S550 to test some new product ideas. So we waited until the big round of 2018 changes and got one.


We have both short term and long term development, testing, and racing goals for this new shop 2018 GT. Unlike the S197 chassis, the S550 Mustang is a "world car", meaning it will be exported to 140+ countries for both Left Hand and Right Hand drive. The Ecoboost made it popular in countries were fuel is $10+/gallon, which helps over there. This exported model is paying off in Europe (out selling 911s in Germany!) and for the 2016 model year the Ford Mustang was the Best Selling Sports Car Globally.

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New coilover S550 inverted rear remote double adjustable monotube design from MCS was tested on our car

This world car status has pushed German, Dutch, and Swedish shock makers to take the S550 more seriously, so we want to test some of the new coilover options from Ohlins, Bilstein, Whiteline, and MCS - this car let's us do that. Last week with the car only days old we already tested a new inverted MCS RR2 version (inverted) on our 2018. Sure is handy having one of these around!


Since here in America fuel is cheaper than bottled water, we got the big 5.0L V8! #Murca Our goals there are to get as close to 500 whp as possible without ever pulling a valve cover. We've seen road race and autocross Coyote 5.0 guys try to get there and spend a fortune in upgrades and repairs, but this Direct Injected Coyote has the right foundation to build on.


New heads, cams, block, bearings, oil pan, fuel injection and compression ratio (12:1) puts power up to 460 hp @ 7000 rpm and 420 lb-ft @ 4,600 RPM (up 25 hp and 20 ft-lbs from 2017 GT) and runs from 0-60 mph in under 4.0 seconds. This article has a stock 2018 GT running a 11.8 quarter mile with the new 10 speed automatic!

What may come as a shock is that we did not buy the $4000 Performance Pack 1 or the new $6500 Performance Pack 2, on purpose. Why? Well most of the parts in those PPs would be replaced in the long term, with our plan.

Powerbrake X-Line X6EL 380x34mm front brake kit for a Ferrari F430 Challenge - similar to what we have on order

Instead we will test the first production 380x34mm 6-piston Powerbrake kit for the S550 on our car. The image above is a similar setup made for a Ferarri F430 Challenge car, so the hats will be different - but otherwise this is what we should have on the car by April 2018. We want to make several other products for this chassis that we haven't seen the aftermarket make yet - this car will let us do that.

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The two SCCA autocross classes we will test this car in are CAM-C and STP

To test these new S550 products there is no other better place than in competition. We are eyeing a number of racing classes and organizations to play with this car in. Jon is going to autocross it in CAM-C, Amy and I will autocross in SCCA's STP class, at least initially. It is always a challenge to build around SCCA autox classes so we will keep it fairly casual so that restrictions for one class don't limit products we can make that we know people will want. There's also the Optima series to look at, which has classing closer to CAM than STP. We will talk more about those class choices and potential restrictions in future posts.

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New wheels (19x11" Forgestar F14) and tires (305/30R19 Bridgestone RE-71R) are already here...

For road course testing we want to run with both NASA and SCCA Time Trial classes, and of course Optima series as well. At first we want to keep 200 treadwear tires in mind, since this "200" limit is becoming so common across many series. We will start by using the 305/30/19 Bridgestone RE71R shown above (first set is here) on a 19x11" wheel (Forgestars just arrived today). We have already completed the first autocross and track tests in this car, which we will cover in our next post. We have a busy schedule planned, so we will have periodic updates in this thread to show testing and racing results.

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Let's get into some tech here. Weight means almost everything in autocross and still a whole helluva lot on a road course. Tire-to-Weight and Power-to-Weight are damn near everything in Motorsports competitions (we expound on this in great detail in this SCCA Time Trials rules discussions, here). I am going to say it right now - comparing published "curb weights" is worthless. The car makers weigh their cars differently, with different options and fuel loads. Some with passengers, some without. Car magazines mostly just re-post those numbers. WE WEIGH CARS, with accurate, digital scales, always the same way. We weigh parts, wheels, and fuel loads, too!

My 2013 Mustang GT was 3518 pounds stock, and 3493 lbs with 2" wider 18x10" wheels and 295s

As I have posted before, the S550 is a bit of a fatty. Sure, its lighter than the 2010-15 Camaro by 100-200 pounds, and it's on par with the 6th gen Camaro, but *heavier than similarly equipped outgoing S197 models (*by +127 lbs, with similar options, comparing our base 2013 GT and our base 2018 GT). The S197s were not exactly lightweight cars themselves.

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Left: A 2017 GT350 at 3703 lbs with low fuel. Right: The first GT350R we weighed was 3649 lbs with 3/8th tank

Much of the S550's weight gain over the outgoing "Stick Axle" S197 chassis was the beautifully designed Independent Rear Suspension that this car got. Unlike the bastardized parts-bin T-bird IRS on the 99-04 SN99 Mustangs, this S550 stuff is IRS DONE RIGHT. This is a game changer, boys. It puts power down like no other Mustang that Ford has ever built. Like... Ever.

This is what makes the S550 worth the weight!

These damn S550s also ride so well I forget its a pony car on the street. It is indescribable - if you have never driven an S550, do yourself a favor and go test drive a new one. Be prepared to never want to drive a stick axle pony car again. Yes, it's THAT much better.


Market Comparison Tangent: It might seem insane to compare a 2013-2018 Scion FR-S/Subaru BRZ/Toyota GT to the 2015-18 Mustang GT, but it is a valid comparison on price, and some folks do cross-shop these cars (esp the Ecoboost Mustangs, which aren't that much lighter than the GTs, just a bit slower/cheaper). Look at the weight on our bone stock 2013 FR-S above - that is a solid ONE THOUSAND and ELEVEN pounds lighter compared to our stripper 2018 GT. Granted it has 200 hp vs 460 hp, but not much less tire (215mm vs 235mm in base trim). The road course baseline lap times compare remarkably close, too! /tangent

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We have weighed dozens of S550s and they range from 3600-3800 lbs

Back to the S550 Mustangs - we have seen weights on 2015-up Mustang V8s as low as 3590 lbs (this base 2015 GT below left) to as high as 3800 pounds (the Shelby GT350 below right), depending on options and fuel load. We always remove anything from the trunk - like spare tires, jack, carpet mat, and easily removed emergency tire inflation kits - to get a fair, consistent "race weight" for a car. Because you'd remove this crap at an autocross or track event. We also try to weigh cars with as little fuel as possible, to equalize our numbers. It doesn't always work out that way, so we include a picture showing the fuel level gauge on our weight pics for consistency.

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We had hoped our base model 2018 GT would sneak into the high 3500s stock, but there has been some bloat in this model as the years have passed. The base GT now has two power seats up front, the 2018 now has a dual mass flywheel and twin disc clutch which adds some weight, as does the new Direct Injected motor (high pressure pumps and doo-dads)


We found the lightest GT possible with our base model 6-speed 2018 Mustang GT, above. We saw a weight of 3645 lbs with low fuel (25 miles to empty) and the optional trunk-mounted spare tire and jack removed.

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The optional mini spare tire is actually really nice but we will likely sell this soon - its a $405 option and $650 from the dealership purchased separately. If someone wants that peace of mind it might be worth the 35.1 pounds it adds. Also, the stock wheels and tires are always heavy, as we saw in the identically equipped 2013 GT at the top. We will still lose weight with 3" wider aftermarket wheels and tires. And more with Sparco race seats. And more with the larger Powerbrake BBK, more with the ARH long tubes, more with the Magnaflow exhaust. Weighing this car at each step is a key part of the game plan. #WeighEverything

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The base model GT comes with these itty-bitty wheels and tires - 18x8" 5-spokes with 235/50/18 all season 400 treadwear tires. These things are AWFUL, and almost dangerous on a car with this power level, but we found this car with the least number of options for a reason: COST and an UPGRADE PATH that made the optional OEM upgraded parts pointless.


One of the theories we want to test is how does a Base Mustang GT compare to the Performance Pack 1 and new Performance Pack 2 cars, both on track and with respect to cost. We also want to compare to the GT350/350R models. And let's compare to the 6th Gen Camaro SS 1LE. And not just in stock vs stock form - on our 2018 GT build we will show costs of parts after each level of modifications, and see how close in lap times we can get to the obviously faster Mustang models on cost.


The 2018 Performance Pack 1 option package includes the 15" dia ront 6 piston Brembo brakes, 19x9/9.5" wheels a 255mm Michelin tire - it was once a $2500 option but is now $4000. Later in March of 2018 we will start to see the new Performance Package 2 option debuting with:


Performance Pack Level 2 includes all of the features of Performance Pack Level 1 – unique chassis and antilock brake tuning, unique stability control and electric power-assisted steering, Brembo™ six-piston front brake calipers with larger rotors, a k-brace, larger radiator, silver-painted strut tower brace and a TORSEN® rear differential with 3.73 axle ratio.

It’s highlighted by a lower stance, a redesigned front splitter and rear spoiler, and 305/30/R19 Michelin Pilot Sport Cup 2 tires wrapped around split-fitment aluminum wheels – 19x10.5-inch front and 19x11-inch rear.

The tires, 1.5 inches wider than those found with Performance Pack Level 1, provide a firmer grip, and work with a retuned chassis to put the car more than a half-inch closer to the ground. The package is available exclusively with a manual transmission.

Custom tuned MagneRide® dampers and quicker steering calibration provide better response. Other improvements over Performance Pack Level 1 equipment include a 67 percent stiffer rear stabilizer bar, a 12 percent stiffer front stabilizer bar, 20 percent stiffer front springs and rear springs that are 13 percent stiffer, all of which contribute to a more stable ride around corners with less body roll.

The PP2 option is $6500 on the Mustang GT, and requires a number of other pricey options to be able to order it. It has almost everything track related from the Shelby GT350 without the problematic 5.2L engine. The 2018 Mustang Shelby GT350 (below) is also one we will compare our build to. It has all of the PP2 bits and 527 hp, plus that Shelby name.


You can see more 2018 Mustang pricing here. We didn't buy a PP1, PP2 or GT350/350R car on purpose - because they come with a lot of parts that we would toss out at the first opportunity. Sure, these versions are faster right out of the box, but they come at a big price bump. We optioned up a 2018 GT with Premium, Recaros, PP2 and it was $52K. The Shelby GT350 starts at $57, the 350R at $65K, and they can quickly go into the $75K range with options, before considerable dealer mark-ups.

This is the actual window sticker from our 2018 GT

We decided to "keep it simple" on this 2018 GT and found a car with almost no options. We found 3 cars locally that were V8 GTs, 6-speeds, and almost nothing else added. This Race Red car was what we bought. Sticker was $36,695 but it wasn't hard to get them to knock $4200 off ($2000 rebate and the rest was just normal "under-invoice" pricing). The final $32,500 price (before TT&L) saved us nearly $20K off the 2018 GT PP2 I had optioned up, and $25K-35+ off the Shelby GT350s. What can we do with $20-35K in upgrades? We shall see... :D


We talk to a lot of new Shelby GT350 owners every week that call us because they want to track their cars and need some front camber adjustment. We ask them what their previous car was, and many of them had never bought a Mustang before. In a lot of cases their former car was a 911 GT3. Ford is doing something right to steal that clientele. So we thought - "Can we do a more focused GT3-like Mustang?"

2018 Porsche 911 GT3 RS is a glorious car - if you have $187K to spend

The Shelby owners we talk to say they like the GT350 because it is so much cheaper than a $144K 2018 911 GT3 ($187K for the GT3 RS). They can afford to take their $57-75K Shelby to the track a lot more often, and these Fords have no "Porsche Tax" on repairs or upgrade parts. There are still plenty of buzz-word technical items on the GT350R that impress their Porsche friends (MagneRide, carbon wheels, rear wing, 180° crank V8 sounds exotic) and the lap times are strong, too.


Most every gear head knows the track-focused 911 GT3 RS model, which comes from the factory with racing style seats, a roll bar, adjustable coilover suspension, wider/stickier tires, better brakes, more power, better aero, and less weight than the regular 911 - basically it has everything that can make this car faster on track, and nothing else. We think Ford triedto do that on the GT350R, but it missed the mark a little bit. There is no camber adjustment up front (so they KILL front tires), doesn't lose any substantial weight, the Recaros are not exactly race worthy seats, no roll bar, and they are still too softly sprung.

Our 2011 GT had a 4-point roll bar, Schroth harnesses, race seats, and fire bottle

So our plan for our shop 2018 Mustang GT will be to make it into as much of a GT3 RS clone as we can, for 1/4 the cost. Is this comparison a bit pretentious? Possibly, but we're going to give it a go. Look for an interior on our 2018 similar to the level (above) we had on our 2011 GT, before that car "went off the deep end" and became more of a race car. We will add racing seats, 4 point roll bar, and proper 6 point harnesses for track use. Adjustable coilovers and Motorsport level brakes. Of course our signature "max-width wheels" and the widest 200 treadwear tires. Some aero tricks that we will rob from the Shelby GT350R (wing) and PP2 (front splitter) initially. It will stay street legal this whole time, too.

Whiteline's Max-G coilover kit will be one of the first shock options we test

Should be a fun few years playing with this car and we hope you enjoy the write-ups. We already autocrossed and tracked this car in stock form to get some baseline numbers and have something to compare to. This post has gone too long so I will write that up next week - and have some better track numbers at Test # 2 (with the first round of upgrade parts) to show also.

Thanks for reading!
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  • 3 weeks later...

Project Update for April 3rd, 2018: Things are really busy around here and I started writing this two weeks ago, and every day that goes by more stuff is going into this 2018 Mustang.

Track Test #2 at a NASA race weekend - the lap times were a welcomed surprise!

I am going to cover what I can quickly and save the rest for next time. This time we will cover the first track test in stock form, the first autocross in stock form, a big round of upgrades, and then the 2nd track test with these suspension and a wheel/tire updates.


On my way to the baseline track test # 1 I found a coin-op car wash and had brought my car wash supplies with me to hand wash the car properly. I don't know why but the First Wash I do is always sort of a bonding moment for me with a new car. (re-reading this - I sound a bit mental)


Up and out of the house before dawn, I left to go to Motorsport Ranch Cresson (MSRC), our chosen road course test track for the past 4 years. I teased the picture below on Facebook - and this was before we had announced that we even bought a new car. Some sharp eyed people figured out what we bought within minutes. I suck at keeping secrets. :D


The track layout we use at MSRC is their 1.7 mile CCW course, shown in the daily map below. This facility also runs a 1.3 mile course, which can be combined with the 1.7 to form a 3.1 mile course, and even the 1.7 mile course "backwards" (CW), which I am not fond of. We stick with the 1.7 CCW because it is the primary configuration that NASA uses, and it has the most room for "oops"... there are 100-200 yards of runoff from any corner, so I can use my hack skillz and push 10/10ths and if I screw up and have an "off", nothing bad happens. :D


We went on a Friday morning where I met up with some friends for a member day. It had been raining hard for two weeks straight. It stopped raining the day before but the ground was saturated, so there was an unusual amount of drainage across the track in a few spots, as shown above. This meant we had to deal with some water on the track, but only in a few spots initially and it dried up (only damn in front of "Rattle Snake") by the time we went on track at 10:30 am.

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I went out that morning with two of my homies: Jerry Cecco in his C6 Z06 and Aaron Sockwell in his C5 Z06. Both of these guys have been testers for Vorshlag in the past; Jerry in his Boss302 that tested our TrackPro suspension and his C6Z which has tested a variety of our C6 specific parts, like our brake cooling and our 18x12F/18x13R wheel setup. He was on 335F/345R Hoosier R7 tires. Aaron's C5Z is relatively new to him but already has rear flares, 18x11F/18x12R wheels, 315/335 BFR Rival-S tires, and some CAM legal aero.

MSR-C Track Test, March 2nd, 2018 - Gallery

My hope was to go on track at the same time as these two and compare the stock lap times of the 2018 GT to them - who have both run this track many times as well. I waited until they both got to the track and we went out at the same time. This would be my 3rd track test at MSRC 1.7 CCW for 2018 so I was still "fresh" on this track layout, but the first time to drive this Mustang on track.

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The car was a week old, had 340 miles on the odometer, and still had the paper tags out back! Temps were 55°F and I had the tire pressures at 31-32 psi with some warmth in the tires from driving 85+ miles out here in the car. As you can see from the picture above right (which I took in a later session that the Corvette boys ran) the water on track was right in the braking zone for the first turn after the start/finish. So let's see the lap...


If you click the image above you will see the youtube video of my best lap, which was anything but pretty. The stock tires are GARBAGE and it amazes me that Ford has upgraded the engine in this car SO MUCH yet still supplies the same base tires they put on a 2005 3V 4.6L Mustang. Laughably bad, borderline dangerous. Of course I ran with the traction control completely off and was not pushing the revs hard - because if the engine torqued up too much in a corner, it would just start spinning the rear tires.

The worst possible tire Ford could put on their 460 hp Mustang - 235mm 400 treadwear all seasons!

Though "Horseshoe" and "Boot Hill" the car wants to be in 3rd gear - the 6 speed gearing of the MT82-D4 is COMPLETELY different than the old MT82 - and it was all too easy to get the rear to step out under power. I was lucky if I could use half throttle through that series of 3 left turns. In normal cornering (turn in) the handling led to heavy understeer, and as you can see from the AiM Solo DL data logging (finally got a tach and throttle trace!) the lateral grip was between .90 (sustained) to 1.02g (peaks). In my best lap (hot lap 3) I was using all of the track surface, and maybe a little dirt, before the tires got so hot they fell off.  

The brakes were atrocious. If I tried to stop with more than .85g it would overheat the pads in two stops (2 corners). After a total of 8 hot laps I lost brakes completely, even babying the pads with 8/10ths stops. Pedal got HARD and would no longer stop (we did have Motul RBF600 fluid in the car - I won't use stock brake fluid on track!) My best lap time of 1:31.412 stacks up pretty poorly to many other cars (see listing of lap times in the Track Test # 2 section), but most of this was due to the base model's sub-standard tires and undersized brakes. We expected the brakes to kinda suck when we bought the car, and had plans to add better pads to these and maybe brake cooling (which we later found to be impossible), before ditching the 14" 4 piston fronts for something more appropriate. The Performance Pack 15" 6 piston brakes are much better factory offerings than these.


After 8 hot laps brakes were DONE so I parked it. The Corvette boys went out again at 12:00 (member days here run 30 minute sessions that alternate between sports cars, open wheel, and motorcycles) but gave up after a handful of laps due to the water into Rattlesnake. This BADLY affected both Corvettes' ABS systems, but the 2018 GT took the wet braking in stride and still pulled the same .85g stopping through this water. It was so sketchy in the C5Z (Ice Mode) that Aaron parked it after trying just a few laps in both sessions. Ford ABS still rules supreme. :)


After grabbing some lunch with Aaron and Jerry at the BBQ joint next to the track, I headed back to work on this Friday, armed with the knowledge that this 460 hp Mustang GT was only 1/2 second quicker in stock form than our 200 hp FR-S at the same track, on equally crap tires and brake pads (1:31.90). The extra power didn't help when the Mustang has to carry an extra 1000 pounds around on only 20mm wider tires... the tire-to-weight ratiowinner in this battle goes to the 2634 pound FR-S.


"Even after 31 years, the SCCA finds new and interesting ways to piss me off"

So the gluttony for punishment in stock form continues, plus I subjected myself to the typical shenanigans of the SCCA to boot! :D I was mistakenly looking forward to this autocross - the first I had done in years in a car I owned and had planned on prepping around an SCCA autocross class (STP). Yea, that was a short lived plan.


Amy and I drove out to Texas Motor Speedway to run this, the first autocross (of 9) for the year with Texas Region SCCA. Jon Beatty (our order manager here at Vorshlag) was to meet us there and run the car in CAM-C, while I was going to run in STP and Amy in the paxed Womens class. We have a lot of friends in this region and all 3 of us were looking forward to seeing our autocross buddies and running in this car - even knowing it would suck on the stock suspension, tires and brakes.

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We got the car teched and headed over to the registration trailer to sign the waivers and see our worker assignments, then walk the course. That's where "the bus went right into the ditch"...


So this region is a stickler for checking your SCCA membership card and driver's license. Some insurance thing they say. My license had expired a few weeks earlier, but I didn't think about it - because I had updated my address and got a fresh one just a few months earlier. They saw the two week expiration and said I was not allowed to drive.


So I got to WATCH as Amy and Jon autocrossed our brand new car for the first and last time in stock form, on the day we debuted to the public that we owned it. I was less than thrilled with the people involved and thus began my spiral of disdain for all things SCCA, once again. :D


I did get to ride shotgun with both Amy and Jon on some of their runs, to experience the awful stock suspension and tires.

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CAM-C is a pretty hotly contested class in the Texas Region SCCA and they had 12 drivers that day. There were 7 seriously prepared cars on Bridgestone RE-71R or Rival-S tires that day, and a few more coming to the class in the coming weeks. So Jon had a pretty tough job to get any regional championship points with such a painfully stock setup.


The grip levels were junk but he was still able to work on corner placement (getting close to the cones), figuring out the gearing of the new motor/trans setup, and overall learning to manage understeer.

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The tire pressures were the only thing we could work with so we adjusted them down slightly (29 psi rear) to try to mitigate the severe lack of grip. You can see the deformation and camber loss in the front suspension in the images posted here. The stock suspension is SO soft that it allows the 3650 pounds of Mustang to flop around like a dying fish.


Both Amy and Jon liked how predictable the 2018 GT was to drive, even on the tiny 235mm tires. Unlike the stick axle S197, the S550 is very easy to drive with no prior experience - no gotchas. It went where you pointed it, just not very quickly. The rear tires struggled to put the power down but Jon felt like it didn't have the grunt of 460 hp engine. That could be a torque management thing for new motors - we barely rolled 500 miles on the odometer on the drive to the site that morning.

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Both Amy and Jon put in some hard driving, yet the car was holding them back. Jon managed a 51.108 sec 4th run while it was just starting to mist rain, and sat as high as 6th out of 12 at one point, but fell to 9th in CAM-C class at the end. Amy managed a slightly quicker 50.646 sec run on her 5th and final run (in another run group), within 2 tenths of the 2 drivers ahead of her, but the STP "PAX" is almost identical to CAM-C (bad), so she took 4th out of 5 in this PAX factored Women's class (a regional only class).

We took video from most of their runs and I have video posted Jon's best one above. On one of his runs and two of Amy's runs the AdvancTrac warning light came on, bonging away with warning chimes. Of course they run with the system completely turned off, but something about the sliding around triggered it to come on again. Nothing bad happened it just freaked them both out. The brakes felt awful but we later found out that the 8 laps on track had killed the stock pads - they were down to only a sliver of material left.

Lastly we will talk about overall PAX placement - our only indication from event-to-event on how well the car is improving since the courses are different each time. Out of 160 carsAmy took 88th and Jon took 96th, so we have a ways to go yet with this car. It did about as badly as we expected for stock suspension, tires, and brakes.


We have worked with Motion Control Suspension for half a dozen years and often they will make something for a new car based on measurements and/or drawings we send them. This time they wanted to test an inverted shock design for the rear of an S550 - so they shipped it to us for a test fit just a few days after we bought our 2018 GT. Nothing of note has changed on the rear shock/suspension from 2015-up on the S550 chassis.


We always try to start with a side-by-side shot against the stock damper. The MCS version looks properly shortened, assuming it was 50mm shorter or so. Which is ideal. The goal here is to shorten the shock enough to allow for a good balance between droop and bump travel - at a lower than stock ride height. The shock length is critical to getting this right... and why so many people have terrible experiences with lowering springs on stock length shocks and struts (all of the lowering gobbles up bump travel... one good bump and BAM, its bottomed out).

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Above left is the stock S550 rear shock mount / shock / divorced spring. Above right shows a spherical upper with the MCS inverted remote double installed on my 2018 GT.

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You can see the lower spring perch clearance and rebound adjuster knob at the bottom of the strut shaft, above left. Then we checked the shock for full bump travel measurement (above right).


These pictures show the shock at ride height (above left) and full droop (above right). This is the ride height we shoot for on S550s = 14.5" center of wheel to fender lip (1" lower than stock). From these measurements we can calculate total wheel travel (5.25", which is a lot) and pick the ideal ride heights based on bump vs rebound travel. Maybe not super interesting, but this is some of the work we get to do when working with shock manufacturers.


There were several suspension items we upgraded in our first round of mods to our 2018 Mustang GT. We're going to keep a running tally of the parts costs and in the case of parts that are removed or replaced, we will adjust the "Mod Budget" as well as lap times at our test track Motorsport Ranch Cresson.


This was a substantial change that happened over 24 hours at our shop, but its a typical round of upgrades that people tend to do all at once. Coilovers, camber plates, swaybars, wheels and tires. We'll break it down into 3 sections below to show what we did and why.

Whiteline Max-G Coilovers + Vorshlag Camber Plates

This is the first of several monotube adjustable coilover dampers we will likely test on our shop 2018 GT. The S550 chassis benefits due to its "world car" status and higher global sales volume in that many higher end shock makers cover this chassis vs the S197 before it. There are good coilover kits we sell made by Ohlins, Bilstein, MCS, and now Whiteline.


This "Max-G" kit is made by a high end Dutch shock maker and is private labeled for Whiteline with spring rates and damping set to their specs. We had such good luck with the "Max-G" Whiteline coilovers on our shop 2013 FR-S (#Agent86) that we decided to test a set for our S550. Whiteline was thrilled to have some good test data so they sent these and the swaybars to us as soon as they heard we ordered this car. The shock kit arrived as shown above, with front springs on the front that were coilover at the bottom but made to fit the OEM style upper perch and strut top mount on top.


We haven't seen many people try this S550 Max-G kit yet, so we got this set in and took a closer look. This kit is made to be a "suspension in a box" and is supposed to work with the OEM front strut top mounts and OEM rear shock mounts. Jason rated the included springs (click on the chart, above left) on our digital spring tester. While the rear's looked to be in the right ball park (avg rate of 535 #/in) the fronts were pretty soft (205 #/in). So instead of "burning an event" with a test of the included soft front spring, we just jumped in and did what we've done on many other "kits" that come with springs - we substituted our own spring and camber plate up front with something more aggressive, and used our spherical rear shock mount as well.


The Hyperco 60mm coilover spring we chose for the front was 400 #/in. When you run the numbers for the motion ratios out back (with a coilvoer spring instead of the stock "divorced" spring location) this gave us nearly an even split with about a 400 #/in front and rear wheel rate. Having sold and tested MCS dampers with many different spring rates on the S550 chassis, we felt this customized 400F/535R spring set would offer a very streetable ride yet should still substantially cut down on the "floppiness" of the stock suspension on track.

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We used a front spring length long enough to keep the spring package "above the tire" while making sure they weren't too short that they had excessive slack at full droop. Out back we used the Whiteline spring and added our prototype "Version 1" S550 spherical rear upper shock mounts - which are admittedly a bit ugly, due to a plating choice I made that didn't work well.

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How were these made? We took the cast aluminum OEM upper shock mounts (above left) and drilled out the crimped in upper washer, which acts like a "fuse" - this pops out when someone bottoms the suspension hard enough in a crash. But it also pops when people convert the S550 rear shocks to coilover springs, and we don't want that. Moving from a divorced spring to coilover spring moves the suspension loads through the shock, and the stock top mount cannot withstand that for very long. We CNC machined a spherical bearing holder section and welded it into the modified stock casting (above right). It works, it just doesn't look very good, so we're not going to sell "Version 1" and instead will make a fully CNC machined "Version 2" with an additional feature we think is warranted. I will show that and explain further in a future post.

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Both the rear shock and the front strut are inverted, which puts the single adjuster knob on the bottom. This is actually easier to access this way on the rear, and up front you just turn the wheels to lock and you can get to them fairly easy. An inverted front strut housing is very strong and has little deflection under lateral loads. We installed the modular camber "slug" inserts with zero offset on the upper spindle mount, to gain maximum wheel room. As we will show below, there is still plenty of camber adjustment on the plates so you don't need to "kick the struts" to get camber in the mounting holes. That gobbles up much needed inboard wheel room, and changes the SAI geometry, so we avoid that trick at all costs.


Installation up front is fairly straight forward. The Whiteline strut is about 2" shorter than the stock piece and getting the front spring and strut out is relatively easy on that end. Above you can see the installed Max-G coilover and swaybar.

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OEM rear spring removal is not that easy - it takes a few tricks. Removing the rear shock while supporting the lower arm, then lowering the control arm doesn't release tension on the spring enough to remove it. You have to unbolt and lower the rear subframe from the chassis to unload the long, massive rear spring that Ford uses in the divorced location.

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Even with the rear spring and shock removed, the rear control arm does not pivot freely. At all. Two guys can hang on this control arm, because it has so much bushing bind in it. It is amazing that this works in stock form, but it somehow does...


You can see the inboard bushings (left side of pic above) and how out of axis they are. These are fighting each other badly during suspension travel. One of these lower control arm bushings is a sealed spherical from Ford, the other is a big nasty rubber bushing, with chunks removed to allow it to rotate in bind. Of course we will look at fixing this down the road.

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Weight loss was a benefit with the aftermarket coilovers - as it usually is. Even with the beefier inverted 44.5mm shafts the pair of Whiteline front struts they were still 5.0 pounds lighter than the stock front struts, with springs and top hats installed.

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The weight loss out back was even more substantial at 9.2 pounds on the pair of rear shocks/springs/top mounts. This is mostly due to the massive OEM "divorced" spring being replaced with a 60mm coilover spring. If you look closely at the "T-bar" lower mount, it is asymmetrical, to kick the lower part of the shock away from the rear axles. If you install this backwards it will be pretty apparent, as the spring will be close to the axle, but Whiteline thought of this little trick to gain more room.


The rear shock is inverted so that the spring can sit "inside the barrel" of the wheel and not restrict the inboard wheel room for wider wheels and tires. With our 19x11" wheel it wasn't even close - we could move inboard another 1/2 to 3/4" and never get near the shock top. Moving the spring out to the shock can sometimes have negative side effects, but on the IRS suspension here with the ample wheel room its a non-issue. The effective wheel rate is higher due to the change in motion ratio - the lever effect of moving the spring out closer to the tire compared to the stock inboard "divorced" spring. 60mm springs are not only lighter but come in a lot more rates and lengths for adjusting around different conditions, tracks, and tire setups.

Whiteline Swaybars and End Links

The factory front swaybars on this 2018 GT were 32.5mm and the rear was 22 mm (0.855"), and of course non-adjustable. Since the rates the Max-G coilovers came with still looked a tad soft for what we had in mind for our next track test we went ahead and ordered up a set of adjustable swaybars from Whiteline.


The Whiteline bits are 35mm front and 25mm rear, with 3 adjustment holes on each side. The BFK006 kit comes with the front and rear bars, body mount bushings, locking rings, and Whiteline shortened/adjustable endlinks for both ends.


Installing these was relatively straight forward and when doing coilovers doesn't add a lot of work. We always test fit any aftermarket bar with the supplied bushings and sleeves, then shim them to fit so that they rotate with "pinkie finger effort". Once they are shimmed and fitted, the body mount bushings and sleeves are removed and drilled/tapped for grease zerks. This allows us to squirt in fresh grease every 6-12 months for a low stiction, noise-free rotation.

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The factory S550 swaybar bushings are not just stuck to the bars - they are BONDED to the bars! This adds massive bind in roll - for the life of my I cannot see why Ford did this. Watch the video below to see what we are talking about. Bizarre. Of course we want the swaybars to pivot freely in the body mounts, without much deflection under load (rubber) or bind when they rotate (roll). This way the swaybar adds a known amount of "anti-roll" and the adjustability gives you some quick track-side adjustment to control under- or over-steer.


shows the S550 swaybar bind and how we fix that

The end links are adjustable in length and have sealed ball bearing ends - not open metal sphericals, that get full of dirt and start banging around in weeks. This is a great for both track-only and dual purpose setups - we love their end links so much we use them in all sorts of customized suspension kits we make, on both race and street cars.

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Weight change was about a wash, with the hollow, larger aftermarket Whiteline bits within a tenth of a pound of the hollow but smaller stock bits. We set them all to full stiff to start with, knowing that the spring rate on these coilovers was not super stiff.


The swaybars were shimmed, drilled for zerks, mounted, and greased. The end links were adjusted and the car was set for ride heights and it was time for wheels and tires...

Forgestar 19x11" F14s + 305/30R19 Bridgestone RE-71R Tires

We have sold a lot of 18x11 and 19x11" wheels for the S550 chassis, and luckily we had some 19x11's on order months earlier. The lead times are really out there lately and having a few sets in line helped us get a set quickly for our shop car. We got them raw and had them painted locally to save time. We picked 19" diameter because of the multitude of tires available in 305/30R19.

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The tire we decided to use for these was a Bridgestone RE-71R. There are virtually no 315mm tires in 19", but this "305mm" model runs a tick big.

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We compared the 305/30R19 RE-71R to the 315/30R18 Rival-S above. The 18" Rival is a good bit shorter, but for the S550 the extra tire height from the 19" tire model actually helps gearing.

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We took weights of the 19x11" wheels and at 26.7 pounds. The flow formed 19" Forgestars are not super light, but this is a normal weight for a 19x11" wheel priced under $500/corner. The 305mm RE-71R tires are heavier still at 32.1 pounds, but that's typical as well.


Three of these RE-71Rs are stacked up evenly with all four of the OEM tires, above. We are adding another whole tire's width of extra rubber, yall!


Once installed we checked the tire/wheel package for rub everywhere - not a problem. The wheels clear inboard and out, but it is of course a tight fit. They even clear at full lock, as shown above.


shows our 19x11" wheel tire clearance on an S550 chassis

There isn't anything magic about fitting 11" wide wheels under these cars, but you can get into rubbing (inboard) or "poking" past the fenders if you get the offsets wrong.

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We had a 2018 GT "PP2" stop in this week and took the pics above. Ford got the offsets a little on the "poke" side with the 19x10.5" front and 19x11" rear. I'm sure they had their reasoning - maybe to clear tire chains in the Great White North - but that's not how we do it. ;)


I was pretty dang happy when I saw this angle, above. That's how you fit 19x11" wheels square on an S550, folks. There is no giant spacer or long wheel studs needed. No, they cannot rotate front to back but neither can the stock PP1, PP2 or GT350 wheels. If you have a decent suspension setup you shouldn't need to rotate. I will show tire wear after our first track event in the next post, to show what I mean.

Initial Ride Heights + Custom Track Alignment

The car's alignment was first tested for max negative camber up front, which was -4.0 degrees at this initial ride height. This is pretty extreme and would only be appropriate for Hoosier A7s on a very aggressive track-only setup.


Instead we setup the car with -3.4° camber up front and -2.0° out back, which is about the extent we would run for dual purpose street/track  use. We used a 1/4" of total toe in on the rear axle and zero toe up front (front toe out kills tires on the street). We left the caster setting in the "forward" (stock) position on our camber/caster plates and ended up with +7.2° caster up front, which is about perfect (we shoot for 6-7 degrees on most cars).

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Ride heights are a little on the low side, and after a few scrapes on the street, we have since raised the car a full inch from these numbers. This happened after our first NASA event, so I will show the new ride heights next time. We ran at these lower ride heights at the second track test, below.

First Front Brake Pad Upgrade + Major Flaw in 14" S550 Brakes

We need to talk about S197 and S550 brakes for a minute, because we found a fatal flaw in the 14" S550 brakes on our car. Not many people knew about this but several folks had seen the same thing, and just never knew why until we showed a few pictures. Bear with us a minute here, its worth it.


All of my previous experience on track in S550 Mustang GTs - both coaching and driving - has been in the Performance Pack optioned cars. These 15" diameter / 6 piston Brembo brakes are MASSIVE and fairly unflappable. I was amazed that I could not cook these brakes when I drove Aaron's 2015 GT at a brake intensive track (ECR) back in December 2014 - on stock pads and fluid!

2015-18 Performance Pack 15" dia front rotors are heavy but effective

These 15" front rotors from the Performance Pack S550 Mustang GTs have regular rotor venting with access for cooling air from the rear. These bigger rotors are much better at absorbing and shedding heat to begin with, but with some forced brake cooling can be made pretty amazing for track use. In 2015 the Performance Package (PP1, which mostly consists of this brake upgrade) was $2500, but in 2018 it went up to $4000 for the same thing - so we skipped it. These are the same 15" 6 piston brakes used on the new for 2018 PP2 ($6500) package as well.

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These are the front (left) and rear (right) brakes that come on the 2015-up S550 base model GT and Ecoboost Mustangs

Well that's not what comes on the Ecoboost or the "basic b!tch" base model GT we got, of course. For 2015-18 base model GTs, Ford picked some pretty looking 14" rotors and 4 piston calipers, but they are not labeled "Brembo". Somebody at Ford must have had a hand in designing these, and they done messed up. They look to be bigger calipers than the S197 cars. This one uses a completely different pad shape, different rotor, etc. The S550 rear rotors are very sizable so there's a small improvement out back.

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The 2015-18 S550 Mustang front 14" rotor (above left) got heavier than the S197 14" front rotors (above right) by about 3 pounds. And usually more rotor weight means more heat capacity, since a brake systems' ability to absorb and shed heat is loosely related to rotor mass. But there is one key downgrade Ford made in the S550 14" rotors. Do you see it yet? It wasn't obvious to me until after I bought the car - and this revelation has shocked people that have seen the issue when pointed out, even people that work at Ford.


I've seen the interwebs all abuzz with talk about using the 14" 4-piston S550 brakes on earlier model cars. We would recommend against this. While they do look pretty, they are worthless for track drivers. I have first hand experience with the 14" brake system's failures on track, which I will explain using the picture below.


What the what!?! If you look at the back of the S550 14" front rotors above notice that the cooling vanes are on the outside! This means we cannot ever add brake cooling to these rotors. They are ass-backwards! The access to the inner portion of the rotor's cooling vanes are only accessible from the outside, and you can't exactly run ducting to the rotors from the wheel side.


With no physical way to force feed air through the back of the rotor face and through the vented rotor section, we cannot cool these down. Ever. They will eventually get so hot that they stop stopping. Which is exactly what we are seeing in use. We ran these brakes with the factory pads with the tiny 235mm base GT tires and they lasted 8 laps on a "brake easy" track, in our first track test # 1. EIGHT LAPS. After the 7th laps in that first test session they were no longer capable of stopping the car at even my mild .85 g stops. I almost went off track, so I came in. The (Motul RBF600) fluid never boiled, I never lost pedal, they just wouldn't stop anymore.

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The S197 "upgraded" Brembo 4 piston fronts also had 14" rotors (above left). The 11.5" rear rotors (above right) used a floating single piston caliper brakes, and these rotors were easy to kill on track (but we can and do upgrade them cost effectively to 14" dia GT500 rotors). The fronts were still just as undersized for the weight and power of the S197 chassis GT as the S550 14" versions, but we could make the S197 rotors work with forced brake cooling from the rear. Vorshlag sells 3" and 4" diameter backing plates and inlet / hose kits to force cooling air from the hub side out through the cooling vanes of the rotor, to shed heat. We tested these for 4 years on our car and they can make the 14" Brembos work for most folks up to even the pointy end of the grid.

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We looked at the pads soon after this first track event (forgot to shoot pics!) and noticed that the material was 85% gone... just a sliver of pad left, with 300 street miles, an autocross, and those fateful 8 laps at MSRC. Those handful of laps KILLED the pads completely. So we ordered new front pads for the NASA weekend (above) and installed them before Track Test # 2. Since we had a Powerbrake 380x34mm / 6 piston big brake kit already on order for our car, and figured a simple pad upgrade would be enough for this "one track weekend" and the following autocross, we just got G-LOC's R8 compound front pads. This is their 2nd step up from their 7 track pad compounds. Mild enough for autocross and some limited daily driver use. Would they be enough...??


After installing the Whiteline coilovers & bars + new wheels & tires I signed up for the next available event at MSRC on the 1.7 CCW course, which happened to be a NASA Texas competition event.


Ignorging the street tire aspect, the car slotted nicely into TT3 class (based on power and weight) using some internet dyno charts from 2018 GTs I found and calculations for avg power (we still had not dyno'd this car yet). We declared a minimum weight of 3800 pounds (with driver and fuel) and a declared avg power of 399 whp (in reality we ran at 3950 pounds with driver and a full tank). We were well within the max limits of the class using these "bonus" modifiers for TT3:

Power to Weight for TT3 = 10:1
Comp weight 3750-3899 lbs = +0.5
OEM Aero = +0.4
Adjusted Power-to-weight max = 9.1:1

3800 lbs / 9.1 = 417 whp avg max

(real weight of 3950 lbs / 9.1 = theoretical 434 whp avg for TT3, for reference)

Not to mention we were on 200 treadwear street tires! We had no prayer of winning the class, but we turned in our sheets and ran with TT3 anyway. I wanted to see how far off we would be from the rest of the class - which had 6 competitors (4 of which were on Hoosiers), everyone else was in gutted race cars, and 4 of those had full aero. We brought a letter opener to a gun fight - but this really was about testing for us.


We also wanted to generate some lap time data for NASA about the modern 200 treadwear street tires, in the hopes of possibly starting a 200 treadwear TT class - at least in this region. We think there are a lot of untapped Time Trial racers who run in other series that limit tires to 200 TW (Optima, Goodguys, some GTA classes, some of the new SCCA TT classes) that could open up new potential NASA TT customers. These guys don't want to run head-to-head against NASA TT cars on monster Hoosiers with massive aero. These tires last a lot longer than Hoosier A7s, we know for a fact, so the cost-per-lap goes way down. Grip level is lower, too.


Due to some last minute work needed to get the suspension installed (this was only one week after doing our baseline lap times in stock form) we were not able to get out to the track on Friday. This would have been helpful to get a good paddock spot and to tech the car for the first time. Every TT car needs a logbook and special tech inspection, which is good for the year.

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We got to the track early (7:15) and quickly found a paddock spot and unloaded our BMW (there to just show it was for sale). Amy drove the Mustang out to the track (1.5 hour drive) with no issues. She quickly got into the tech line and waited. I ran to my TT meeting and came back, and the line had grown but hadn't moved. At this rate it might take hours to get the car teched. So we jumped outta line, went to G-Speed's shop on site and got the logbook.


Sadly NASA has removed the right to give out annual Tech stickers to even their certified logbook shops, so we had to get back in line anyway. We finally got the Annual Tech sticker but by this time I had missed the TT Warm Up session - which is used to only get lap times for gridding purposes.

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With no lap time I had to slip into the first open spot on grid for the non-timed cars who missed the warm up, which was 34th! We had 51 TT entries this weekend, so it was a bit crowded on the 1.7 mile course. We also had over 270 total entrants that weekend - a NASA Texas record as well as a record for any event at MSR Cresson. This meant people were parked everywhere, and the all groups had to grid on part of the 1.3 mile course.


51 cars in TT is insane - we have never had that many sign up before. Luckily we never had all 51 TT cars on track at once, but it sure felt like it! ;) In that first session I ran the Big Red Pig passed at least a dozen cars, maybe more. It was a total mess but it was another lesson learned - get your car teched before race day! Vorshlag is a certified NASA "HPDE" tech shop but not a "Logbook" shop. Not yet - we are scheduled to take the SFI exam soon.


Somehow my old TT3 lap record in our 2011 GT, "Big Red", from 2014 was still holding strong (1:17.310) all day, and a previous customer KenO was chasing it once again in his fully prepped E46 M3 (shown above). He was on a sticker set of A7s with the most power and aero he had ever run on the car. I suspected he would win the class and take the TT3 record away from us...

in-car video of our 2014 TT3 track record lap - which was still holding

On this first day the TT3 record still eluded him, but Ken was faster than he'd ever been before. His is a dedicated TT3 build with no compromises, and I was lucky to be within 5 seconds of him on street tires. Amy was also co-driving the car all day in HPDE4 an I took some laps with her using the helmet radios from the right seat, and she dropped a bunch of time.


The handling was spot on all day, and the only adjustments I needed to make were to tire pressures. I was looking at scrub at the sidewall and adjusted hot pressures to 34psi front, 33 psi rear. #500psi There aren't any major bumps at this track but damn, this suspension was downright plush. The roll and dive weren't bad and it was super easy to drive. I did managed to fuel starve the engine in a long left hand sweeper at 1/2 tank of gas, which triggered a CEL on the dash. We kept the fuel tank full for each session after that. The CEL stayed lit all day and into the next - but it ran great (it went off in her drive home Sunday night).


I fought all day with traffic, slowly working my way up the grid to 8th fastest TT car at one point. Since we grid based on your fastest lap times, the later sessions helped removed slower traffic from in front of me the next time sessions. Strangely I ran almost the exact same lap times in session 3 and 4 -within .001 sec of each other - but was still only 3rd fastest out of 5 in TT3 class. To have already found EIGHT seconds on my first day of testing - in heavy traffic - was outstanding, but I knew there was more in the car.


The brakes were not good. At all. I had to baby the braking to keep from overheating the rotors and upgraded front pads. Once again I never lost the pedal, so the fluid was fine, it would just lose stopping power if I pushed the brakes as hard as I used to push the S197, so I had to brake earlier and less aggressively or it wouldn't last 2 hard stops in a row. There was ample time between my TT sessions and Amy's HPDE4 sessions to cool the rotors down, so it was not compounded from double driving the car. Weather was beautiful all day, sunny in the afternoon, so we packed up and headed to the hotel to clean up and rest after the last HPDE4 session. We foolishly left our sun shade partially extended on the trailer...


As perfect as the weather was Saturday it was 100% more awful on Sunday. We woke up to hear the wind howling and rushed from the hotel to the event site. Sure enough we were greeted to a trashed sun shade. Lots of E-Z-up tents were down and destroyed, everywhere. Wind was blowing hard all day, which made it COLD.

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We managed to retract and secure our now ruined sun shade and then got the Mustang ready with plenty of time to make the "golden session" of the weekend - the coolest of the day, TT session 1 Sunday. Was worried the wind might slow us down but it didn't. I started in the 10th grid spot (really 7th, we had some no-shows) and quickly passed the car ahead of me when he spun off track in the first lap, shown below.


That was good because I was held up badly on the first hot lap. Lap 2 was pretty good and my times fell a little, then lap 3 was perfect. Tires were up to temp, brakes were still working. Lateral grip on the RE-71R tires was 1.2g sustained with 1.34g spikes (see below). Braking was limited to about .90g stops, otherwise it would overheat the rotors/pads (it could spike to 1.0g stops but only about once every lap, for one good stop). I also had to compromise the last corner on my best lap because I had a 1:10 sec lap TTU car driving up my tailpipe into the last turn - scary fast! I got outta his way and braked a hair early, but that 1:21.733 lap was still 1.5 seconds better than Saturday, so I "banked the lap" and came in. Rear tires were already getting hot.


When I used 2nd gear in "Rattlesnake" it could easily spin the tires on corner exit. Even 3rd gear exits on "Little Bend" and "Boot Hill" had to be made at part throttle or risk sliding the rears. The Base GT has an old style clutch Limited Slip Diff, unlike the Torson style diff that comes in the PP1/PP2/GT350 models, so we plan on upgrading to a Torson-style LSD later this season.


I didn't run in any other sessions that day. I felt like it would be wasting consumables to try to catch P2 in TT3 class, and I might only find a tenth or two. Instead I worked with Amy (see above) coaching her for a couple of sessions, and she found more confidence and lap time. We packed up by lunch time and headed home for some hard labor at the house - we're building a shop behind our house and we needed to shovel 6 yards of crushed concrete to start making a road back there. It was back breaking work, so we bought a tractor the next week - we have many more tasks like this to tackle.


Some of the temp data I am getting via OBD-II isn't super accurate, but the dash does have a readout for some things. Cylinder head temps were at 220°F after my last session, oil temps were creeping up into the "yellow". This car does have a factory oil cooler (at the oil filter, aka: the oil heater) but we may do something more substantial this summer.


Sunday's final results were about the same: the #BigRedPig took 3rd out of 5 in TT3 class - and everyone got quicker. KenO finally beat my old TT3 record with a 1:17.1 lap, and the second place driver dropped into the 1:20.3 range, which I was never going to catch that day. Final thoughts - the stock seats suck, big time. I had to go to the chiropractor Monday to pop things back in place, ha! The crushed concrete shoveling that night didn't help, either. Great event overall, lots of good data learned. To end up 10th fastest out of 51 TT entries, in a car we drove there on street tires, was pretty remarkable.


We want to show where we are on lap times vs overall budget for this car, to compare against other NEW Mustang options. I am not trying to compare against an older car, or another new car model, but instead between the various OEM 2018 Mustang purchase options. I will show the MSRP or street price for models at our time of purchase + our mod costs to date. Sure, deals change and rebates come and go - these new purchase price numbers are relevant for Feb 2018.

2018 Mustang GT PP1 w/ Premium + Recaros = $48,270
2018 Mustang GT PP2 w/ Premium Plus + Recaros = $51,280
2018 Shelby Mustang GT350 = $58,140
2018 Shelby Mustang GT350R = $65,640

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Our "basic b!tch" 2018 Mustang GT base model 6-speed = $32,500 (what we paid)
+ Whiteline MAX-G+ Coilover Kit for S550 Ford Mustang GT - TrackPro = $3,154
+ Whiteline Front & Rear Adj Swaybar Kit, S550 Mustang = $585
+ G-LOC Brake Pads, Front, Base GT 4-piston, R8 = $234
+ Forgestar 19x11" F14 wheels = $1720
+ Bridgestone RE-71R 305/30R18 tires = $1368
$39,531 in the budget, dropped ten seconds a lap from stock, and we cannot find a quicker lap time from any stock S550 at this track.

Now we have spent less than that, since we make some of this stuff and we're a dealer for the rest. And we kept labor out of the tally because not everyone pays for wrenching. I'm not going to count fluids - those upgrades are a must, and would be done on all of these Mustang options for track use. That's like tracking fuel costs - its a consumable. The tire and brakes are consumables, but I'll factor those into the budget since these really are upgrades. When/if we change out one of the "mods" listed above we will show the subtraction of their costs and the addition of the new upgrade in place.

Remember I showed Josh's stock Shelby GT350R lap time on PSC2 tires earlier in this thread at a
lap (different driver, so its hard to compare). Sadly I do not have any first hand experience in a stock S550 at this track, yet. If I can finagle my way into a few laps in any of the above cars I will update the "lap time list" below (any volunteers??) For now here is our list of data logged videos showing lap times in cars I have driven personally at MSR-Cresson on this same 1.7 mile CCW configuration:
  • in our stock 2013 Scion FR-S
  • in our stock 2018 GT
  • in our 2013 Scion FR-S with camber and front brake upgrade
  • in our 2013 Scion FR-S with Whiteline Max-G coilovers & bars
  • in Todd's stock 2016 Focus RS
  • in Todd's Focus RS on coilovers and camber (which then ran a 1:23.658 on 275 Bridgestones later that day)
  • in a Spec Iron Mustang on Toyo tires (with passenger)
  • in our TTD prepped E46 330 (195 whp)
  • in Jerry's stock 2012 C6 Z06
  • in Joe's modded 2013 1LE Camaro on Hankook RS-3 tires
  • in our TTC prepped 1992 Corvette (288 whp)
  • in Joe's stock 2017 Corvette C7 Grand Sport
  • in our 2018 GT on Whiteline Max-G coilovers & bars + 305mm RE-71Rs
  • in our old TT3 Prepped 2011 Mustang GT on 335/345 Hoosier A7 (447 whp)

As you can see the 2018 GT has both one of the slowest and one of the quickest lap times listed here. It improved a dramatic amount in only one week, and we have more plans to upgrade brakes and power very soon. Gonna be fun to see how far we can push this one!


Next time we will show our second autocross - with the new suspension and tires. Or will the SCCA or other outside forces conspire against us and thwart out second autocross test????


We just ran an SCCA Club Trials event event at ECR last weekend (above), which was a very brake intensive track. Before this event we upgraded to the craziest G-LOG compound pads, both front and rear, to deal with this track. Will it work? Can the Mustang hang with the swarm of Corvettes and 50 time trial racers that attended? Tune in next time to find out!

Thanks for reading,

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  • 4 weeks later...

Project Update for May 1st, 2018: We have been testing our 2018 Mustang on track and finding all sorts of issues, bad advice, and eventually the right fixes. Read along and learn what we have found in our first hand testing, along with a number of videos I shot discussing what we have found. Lots to cover, so I will "try to be brief", ha! :D


In this round we will start with coverage of Track Test #3, where we ran the car with a new set of R16 pads on the 14" brakes (2nd round of brake mods) at Eagles Canyon Raceway (above). Poor braking endurance for both drivers, me and Amy. We also cover an autocross we tried to go to, and show the reasons why the car didn't make it.


I had hoped to cover a a few other events we have attended since my last post: Track Night in America at NOLA, Optima 2 day event at NOLA (above), another track test at MSR-C, but the post ran long so I will save that for next time. Let's get started...


A little bit of a time jump backwards 4 years, to show some baseline track testing I did in a stock 2015 GT PP car at Eagles Canyon Raceway in 2014. I used to consider this my home track for many years, and have a lot of laps here. It is known to be a BRAKE KILLER track with a bunch of long straight always followed by tight turns, where you have to shed a LOT of speed: esp Turns T3, T6, T7, T9, and T11.

The track map of the 2.5 mile ECR layout, which has a lot of elevation change for a Texas track

Every December ECR held a Charity event where they collect money, toys and canned food for "Toys for Tots" - and they only charged $50 for a full day of HPDE fun. We went every year and 2014 was no different. The super low entry cost meant this event always PACKED with drivers, as you could imagine.


I drove a bunch of cars that day and recently Aaron had to remind me about this track event - which was my first drive in an S550. It had slipped my mind completely. ECR is a 2.5 mile course which is known to be BRUTAL on brakes but it has no high speed corners, and it got pretty bumpy for a while there, so I haven't driven here much since 2015.

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I mostly remember that day being very hectic. It was the 2nd time I drove Jerry Cecco's 2012 Boss302 (above left), to perform the "after" track test with the prototype TrackPro coilovers we had built for this car. It was also last time I drove our 2011 GT on track (above right). I had a bunch of customer cars out there, people I rode along and coached with, etc.


Aaron Sockwell had just picked up his brand new 2015 5.0 6 speed Performance Package GT, above. It was an unusual "base" interior with the only option being the PP1, which came with the Torsen diff and 15" 6 piston Brembo brakes for $2500. Heck of a deal back then (its $4000 for 2018 model) and it was the first S550 I ever drove on track.

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I drove two sessions in the car. The first time I was by myself (first pic in this segment) but without a lap timer or camera. It was just a few laps but it felt amazing, so I begged Aaron for a few more laps on track...

Event Gallery, pics and video: https://vorshlag.smugmug.com/Racing-Events/Toy-Run-ECR-120614/


from ECR test in bone stock 2015 GT PP car - Dec 6, 2014

In the brief second session shown in the video above I am driving and Mark Council was in the right seat for some commentary. This time I had a video camera and a smartphone with Harry's Lap Timer on board. The video above shows 4 laps in this stock 2015 Mustang GT where I drove some ~90% laps. Fastest lap was a 2:06.01 in this bone stock car with the OEM pads, fluid, etc. Ignore the G-load trace after the first lap - the GPS data and timing seemed accurate, though. These factory 15" brakes were pretty amazing to me at this brake killer track back then, and it's what pushed me to buy these for our car (you will see this later in this post) for interim use.

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While we are time traveling looking at ECR lap times, for comparison back in Oct 2012 I drove a 2:07.31 lap in a 2013 GT (stock but with 18x10" wheels and 295/35/18 NT-05 tires) but killed the brakes and had a huge "off" at Turn 7 doing that. That car had abysmal 13.2" base 2 piston brakes that were new pads when that session started, on the metal backing plates after 15 minutes.

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We took this same 2013 GT back to this track on the same wheels/tires but with the 14" 4 piston Brembo fronts, brake cooling, and some mild coilovers and ran 2:03 laps. Which is the same lap time we ran at ECR in our red 2011 GT on these same 295mm 200 treadwear tires (before Hoosiers & Aero). Keep this 2:03 lap time in mind for the ECR event section.


We ran the 2nd track test with the 2018 GT at MSR-C (NASA weekend) on stock rear pads and new G-LOC R8 fronts. In hindsight the R8 pads weren't the best choice for how we were using the car - heavy car, lots of power, decent grip level, driver is a hack (me).


The OEM front pads were destroyed in the first MSR-C track test, 8 laps on the stock tires, nothing left. We went with the replacement R8 fronts but left the old OEM rears on for NASA event at MSR-C. As you can see above, the rears were down to 1/4 pad life after this 2nd track test (2 days, 2 drivers), so we bought R16 rears for use at the next weekend. As I mentioned before, using the bass-ackwards 14" inverted hat rotors, the rotors overheat very quickly. The rear rotors are built the same way.

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We had a set of Powerbrake 380mm front brakes on order, but we had to buy some time. To hopefully get a little more brake system endurance, and with about half the life of the front R8 pads destroyed during just the NASA weekend, we bought a new set of R16 compound G-LOC fronts as well.


Not too many folks had made loud noises about how bad the 14" S550 base GT brakes were, so at the time I just hoped it was just a pad compound issue (the R8 is their entry level track pad). Here's how the pads are ranked:

G-LOC Pad Compound Chart
GS-1 ~.45 ambient up to 800°F (426°C) - Street pads
R6 ~.51  ambient up to 1000°F + (to 537°C+) - Autocross pads
R8 ~.55    74°F-1250°F+ (23°C to 676°C+) - Entry level track pads
R10 ~.59    118°F - 1475°F (47°C - 801°C) - Track pads
R12 ~.62-.63   173°F to 1860°F (78°C to 1015°C) - Track pads
R14 ~.60   210°F to 1400°F (98°C to 760°C) - Endurance pad for light cars
R16 ~.65  255°F to 2000°F (123°C to 1093°C) - Aggressive track pad
R18 ~.70-.71  610°F to 2100°F+ (321°C to 1149°C+) - Aggressive track pad

We have sold G-LOC pads to HPDE folks with these 14" S550 base brakes many times, I just hadn't ever driven on or ridden in any S550s except for 15" PP brakes before buying this car. With no way to cool these backwards 14" Front rotors we just hoped that the next test at ECR with "better pads" would show some promise. Pushed some Motul RBF600 fluid through and system (it wasn't boiling or discolored) and then we looked at the bumpy conditions at ECR....


I wasn't happy with the ride heights we picked initially. The rear shocks would run out of travel on heaves and big bumps on the street, and with how bumpy ECR is, I had the guys raise the ride heights at all 4 corners.


The numbers above represent a 7/8" increase up front and and about a 3/4" ride in the rear. This 14-1/2" setting represents our ideal "dual purpose" (street/track) S550 ride height, with coilovers. To take tire height out of the equation we measure from center of wheel to fender lip. We got that squared away, double checked alignment settings, and loaded up for ECR.


I was excited to get back to Eagles Canyon Raceway after about a 3 year hiatus. The new owners have done some much needed track improvements, and it shows. Amy and I both signed up to drive our 2018 GT at this SCCA Time Trial event. Amy ran in yellow group, I ran in red group, both of which had Time Trial competitors. Lots of fun, and somehow we ended up 6th fastest time out of 50 TT cars and won our class.


It is "less than ideal" to double-enter any car for any track event, but two people driving the same car on a one day Time Trial - with marginal brakes at a brake killing track - was a terrible idea, but we did it anyway. And we ran back-to-back in several sessions, which did not work. At all.

Event picture and video gallery: https://vorshlag.smugmug.com/Racing-Events/SCCA-Club-Trials-ECR-033118/

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I won't go into a bunch of boring detail here - this isn't even our "chosen test track" - but we did learn a lot at this ECR event. We learned that the 14" S550 brakes are pretty much hopeless for us. Even with fresh R16 pads front and rear, good fluid, and careful modulation, I could not brake hard for more than ONE LAP before the brakes were done. Again, it wasn't boiling fluid, it would just overheat the front rotors and the car would no longer stop.


This was only our 3rd track event in the car, and 2nd on the new suspension, so we were still experimenting with shock settings, camber, tire pressures. I have been raising the "hot pressures" on these 305mm RE-71R tires from 28-30 psi (based on recommendations) to 34-36 psi. This was after seeing too much deformation and shoulder scrubbing with lower pressures. #500psi


I ran a quick-ish 2:02.754 lap in the 2nd lap of the very first TT session of the day, avoiding a spinning Corvette in front of me on that lap. I struggled with the brakes after that lap, even in a dead cold car we took right out of the trailer. After 3 laps I came in. Then the car cooled down a bit, then Amy went out and had a lot of fun, as for once she got the car "cold" and then gave it to me hot in the red session right after she ran - brakes and tires would be overheated. This went on for 5 sessions, and eventually I just stopped going out. In one session I had a complete loss of brakes in the 2nd stopping zone on lap 1, went off, and blew off the session. I ran a nearly identical 2:02.699 lap in a later session, also in traffic.

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In total the car ran 9 sessions that day, and it was a bit hectic with a LOT of traffic putting in wildly differing lap times in even the yellow and red groups. At least they were gridding us by lap times, so I was usually P1 or P2 in our group. Amy and I agreed that I would skip a session, give Amy the car two sessions in a row, and then I'd go out after she skipped her last session.


This way the brakes might be cool enough for me to make ONE hot lap. I knew the two previous 2:02.7 best laps were slower than the car had in it, but the track surface was getting warmer so I doubted I would find much time. But with a cooled off car, a slow out lap (you can see I'm just talking to the camera and keeping the C6 ahead in sight in my video below), and a focus on getting my FIRST hot lap in clean... I managed this.


of my final session, first hot lap was a 2:00.619

That was a pretty decent lap, if I say so myself. I've driven a LOT of cars out here in the past 10 years but never have I run a 2:00 flat lap in anything with street tires. It took every amount of restraint I had to not "over brake" any one turn on that one hot lap - and the brakes were getting worse in every major braking zone - but it was just enough.

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Eight of the top 10 cars were Z06, Grand Sports, or other Corvettes with lots of mods. KenO's E46 M3 TT3 race car with aero on Hoosier A7s took FTD and our piggy Mustang with no brakes managed 6th overall and "won our class". Don't ask about classing here, its something based on autocross classes and PAX factors that will make your head spin. We were 4 seconds ahead of the next Mustang, another S550 on RE71Rs. I was happy with that, considering how marginal the brakes were. I look forward to coming back here with better brakes to see if we can dip under a 2:00 lap on street tires.


This first video explains our experiences with the S197 4 piston Brembos and then our frustrating experiences with the 14" S550 base GT brakes.


is the first in a series of videos about these brakes we made and we feel it is worth watching.


So while I missed the March 4th autocross with our local SCCA region due to a drivers license debacle, I was excited to finally autocross the car - and this time on real suspension, wheels and tires. Jon had made us some magnetic door cards for STP/W and CAM-C classes. We had another race car in our trailer but this is a street car, right? So we decided to drive the car to the event, across town. These are street tires after all!

Well there was a lot of construction going on in our area and we think the car got a flat leaving our neighborhood. Amy was driving and said "Hey, its really pulling pretty hard to the right." Hmm... turn around and go back to the house to air up/check the tire, or drive down the road to the gas station to check it there? We needed fuel, so I said to heck with it, let's go another 2 miles down the road. Mistake.


She's on the highway, within a half mile of the gas station, and the tire lets go. Pop! This car just does NOT want me to autocross it! :D And while we had the factory optioned spare tire and lug wrench in the trunk - we didn't have the jack or the right 19mm socket for the lugs we had on the Forgestars...

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Jon was just ahead of us on his way to the event (he would be co-driving) and when we called, he ran back to his house, grabbed a floor jack and the right socket, and we put on the spare. He brought a plug kit in case it was just a flat, but when we removed the tire and saw the inner sidewall gone, we knew it was way beyond saving this day.


Every time I make a mistake in my life I try to learn from it. I haven't had a tire blow out in a sports car in... well, ever. And getting caught with the wrong lug wrench and no jack was a dumb mistake, so I bought a cheap 1/2" torque wrench, thin wall lug nut long socket kit (17, 19, and 21mm), and a short 1/2" extension. Probably spent $50 but I won't be stuck again. I actually doubled up on all of this so my 1/2 ton truck would have the same setup on board.

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I also bought the Ford Racing TMPS kit shown above, along with the programmer. Having on-board tire pressure readouts is super handy and would have prevented this blowout completely - the instant the pressure dropped below 30 psi we would have seen an alarm. The next time I have these tires off these wheels we will install these sensors, program them to the car, and never be without tire pressure data any longer. #500psi  #streettires

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Sadly the Right Front tire (which took the most wear at the MSR-C event) that popped had 6/32" of tread left, as measured above left. They only come with 7/32", so it was wearing nicely! Instead of buying just ONE replacement Bridgestone tire I bought TWO - so we would always have a spare with us in the trailer, for any unforeseen mishaps in the future away from home or the shop. And by damn this would be the LAST time we did NOT tow this car to an event. Three people missed out on autocrossing this day due to our lack of a proper spare RE-71R tire, TPMS sensors, etc. This sure isn't going to happen again over a $330 tire or the ease of loading/unloading a car in our trailer.


When I saw an opening at the normally sold out Optima series event at NOLA coming up in a week, without much thought I signed up. I knew this track well, plus we found a Track Night in America test the Thursday afternoon before the Saturday-Sunday Optima series event. Time for an Intermediate Brake Upgrade and subsequent test...

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Since we might use them only for one event I got the cheapest Centric rotors and rebuilt calipers

I knew this track would need better brakes than our 14" stuff, and our prototype S550 380x34mm Powerbrake kit wasn't going to make it in time. With little to no research I ordered some Centric 15" rotors and rebuilt Brembo 6-piston calipers off of the 2015-18 Performance Pack Mustang GT. There was some small hardware to round up, new front pads to order (G-LOC R16 once again) for the new calipers, but the brake hoses would fit. There would be zero time to do a local track test before going to the Optima event so this was a total roll of the dice! But again, I had used the stock brakes at ECR in 2014 with good luck... they should work fine.


It was a pretty tight schedule and everything we needed only showed up with hours to spare before we loaded up for the 9 hour tow to NOLA. The "Tech Tip" video in the section above shows many of these caliper/rotor weights, as I shot that as soon as the calipers and rotors arrived. The above gaggle parts were also ordered and arrived, including: ARP long wheel studs for the rear, Ford Racing hubs with ARP long wheel studs for the front, and Ford Racing trailer tie-down hooks.

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First Ryan put the hubs, rotors, and calipers on then fabbed up prototype 4" cool brake backing plates for these 15" OEM brakes.

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These prototype brake backing plates (we will have these in production later this summer for the S550 15" PP brakes) serve two purposes. First, they cool the front hubs - which get hot and become a wear item over time (just like we saw on the S197). Second, they pump air inside the "hat" of the rotor, seal the air into this area, which then forces it into the vented portion of the rotor - which acts as a centrifugal pump and pushes this cooling air through the center of the rotor casting, to cool both the inner and outer rotor faces.


We have seen a few people propose that you can "make brake cooling for the 14" inverted hat rotor", but we feel that is pretty much pointless. While this might help cool the hubs, it would do little to cool the rotor itself, especially the outside face - since there is no way to pump air through the vented portion of the 14" rotor. This is a lot of work for very little benefit. Now if there is a non-inverted hat 14" rotor on the market that fits the 14" 4 piston calipers, yes, that might be worth trying. But we've moved beyond the 14" bits on our car.


We stuck with the 14" brakes on our 2011 Mustang for 5 years mostly because of one thing - we ran 18" wheels that didn't clear the 15" brakes. At the time we were using Forgestar F14 wheels in 18x10, 18x11 and 18x12" widths. And back from 2012-2015 the Forgestar F14 wheel in 18" could barely clear a 14.5" rotor/caliper setup.

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Forgestar knew that the 15" / 6 piston Brembo kit was coming down the pipe from Ford (S197 GT500) so when they introduced a newer wheel design - the CF5 5-spoke above, they changed the barrel to clear this 15" / 6 piston profile. The shape of the inner barrel on the older F14 is very different than the newer design CF5, which I am holding below.


Starting in late 2016 Forgestar began phasing out the old tapered barrel design of the F14 to the "stepped" barrel (above) of the CF5. So if you have 18" wheels of the F14 style from this company bought in the last 2 years they likely look like the black wheel above and can clear the 15" brakes. Barely.


Of course many S197 and S550 drivers have moved up to 19x11" wheels due to the abundance of 305/30R19 street tire options available. But when it comes time to slap some Hoosiers on this car well... we will likely go with 18x11" wheels, so we will have to watch out for that rotor/caliper to inner wheel barrel clearance.

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Next we changed the fluid in the manual trans at 1000 miles, but

to check for the rumored "trash/metal" that would be in the fluid. We strained it, looked perfect, but still replaced it with Motul DCTF.

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Engine oil was also upgraded to Motul 5W50 Ester based synthetic. This lubricant is one we have used on several race cars in the past couple of years and they tend to drop oil temps by up to 30°F. If any engine needs it, it's this one.

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During the oil change we also upgraded the tiny OEM oil filter to this larger Mobil1 filter that has at least twice the volume. It uses a synthetic filter element and is a Mobil1 Oil Filter part number M1-212, cost is around $17. It clears all of the "stuff" around the filter by a mile. The plastic oil pan still makes me giggle, but I'm sure there was a cost/weight savings there.

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We had not seen any proper brake cooling inlet kits for the 2018 GT's new nose, so I asked Ryan to remove the bumper cover so we could have a better look. After looking under the skin we noticed that the area Jason and I wanted to draw air from was fairly unblocked, so I asked Ryan to make a quick 4" oval inlet to bolt into this lower grill section.


In the same general space we found a good spot to bolt a front tow hook to, behind the 4 bolts that hold the bumper beam in place on the right front corner. This tow hook was cut from 1/4" steel plate, welded up, painted, and bolted in place. A small slot was cut for the tow hook as well as a 4" oval hole for the inlet duct. We plan to make these in production later this summer and offer them with modified lower grill inserts (which just snap in place into the pumper cover). Some of the other options out there require you to drill into the bumper beam (its hard AF!) or worse, remove it altogether. This is a simple bolt-on part that doesn't sacrifice crash structure or require you to cut into the upper grill or painted parts of the car.

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The rear bumper is not any different than the 2015-17 models, so we looked at what was offered for a rear tow hook. Oddly enough they tend to mount where the lower/center mounted reverse light goes - and we don't want to remove that. The others require a hole cut in the rear bumper cover and/or the removal of the license plate. Not really what we wanted.


We looked at the rear section, the bumper beam, and the many ways other shops have made rear tow hooks. And like in the front, we found that bolting behind the bumper beam was the least intrusive, strongest way we could find. Routing the hook above the exhaust tips made it so nothing had to be cut whatsoever. Maybe someone else has done this but we hadn't seen it yet. Another part we will make for all 2015-18 S550s later this summer.

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We have a little tool that allows for on-car removal of splined, press-in wheel studs... but Ford did us no favors here, and there's not enough access to install the longer ARP studs. So the rear hubs have to be removed.

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With a few fixtures and a 30 ton press the new ARP studs went right into the rear hubs pretty quickly.

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The OEM front hubs felt fine (above left) but I wanted the longer studs for this car, and ARP was sold out (we could only find 10 quickly). So we bought the Ford Racing front hubs with the same 3" long ARP studs installed, and the old hubs will become spares in the trailer.

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The images above compare the base Brembo 4 piston calipers to the PP's optional 6 piston calipers - which are similar in size and mass. The pads are different between the two but also similar in total size.


In our rush to install these parts, on a 2 day timeline before this Optima event, we neglected one piece of advice from a racer, Chris Wynne. He told us we might get a poor pedal feel with this 15" PP brake setup using the stock 4 piston master cylinder and booster. While many other folks that saw me posting about these upgrades said that this was an easy upgrade, and that "The Ford Racing kit doesn't come with the PP master or booster, so it isn't needed". The latter folks were wrong, wrong, wrong. But we wouldn't know that until we drove 9 hours to New Orleans and put it on a race track.


I took a quick drive around the block after they bled the new brakes, it "felt ok to me", and we tossed it into the trailer. I foolishly thought we might have a shot at this Optima GT class if we can get past the D&E judging (more on that in our Optima coverage), but that was wishful thinking. Having functional brakes matter more than you'd think.


This post is running long so I will share the results from our two TNiA / Optima track events at NOLA and the Optima Speed Stop/D&E/Autocross events next time. Yes I finally got to autocross this damned car. Surprisingly I won one of the Optima competition segments, just not the one I was expecting. It all came down to not having any brakes.


One piece of good news from this round of mods - the Ford Racing "tie down hook kit" for the S550 chassis was a real nice addition and makes hooking the straps up inside the trailer a whole lot easier. We modified the front tie down hook mounting locations to make it even easier - I will get pics of that on the lift and show it next time. We will also show the fix for the 15 PP brakes we needed - the PP's master cylinder and booster. Then the track test at MSR-C after that was installed to prove it. There's a lot more going on also, but I will cover this next time.

Thanks for reading,
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  • 2 months later...

Project Update for July 26th, 2018: It has been a hectic few months since my last post, and it took me nearly 3 weeks to finish this post after I started writing it. We have been dealing with moving our business into a new shop and finishing construction on this new building, which I talk about at the end. It also got VERY hot here in Texas in June and July. Due to time and heat we haven't run the car since our last two track events in May. But we have a lot of testing and competition events to cover since my last post.


I failed to cover many of these in the last update, even though some of them had happened already. We had a Track Night in America road course test at NOLA (April 12), competed in an Optima 2 day event at NOLA (April 14-15), did another private track test at MSR-C (April 22) to test some brake system changes, competed in a NASA Time Trial at COTA (May 5-6), and an SCCA Club Trials event at MSR-C (May 12).


I will try to cover these events as well as some upgrades and changes we tested on our 2018 GT, then list some of the many parts piling up waiting to be to installed - when we have a few hours to spare to work on a shop ca.


I don't hide it: for most events we take this street legal Mustang to, I would rather tow the car there in our enclosed trailer. There are several reasons for this: to avoid tire issues on the road (like the blowout we had last time?), to reduce the heat cycles on the tires (even 200 treadwear RE-71Rs are susceptible to aging out), and to be able to bring ALL of our gear to the track in comfort and security (tools, spares, bikes, food, covered shelter, etc). After an exhausting weekend at the track it sure is nice to ride home in a big cushy seat inside the F350 - with no worries.

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Strapping down a car safely to a trailer deck takes time and the right gear. To speed up this process we always try to make or buy some tie-down hooks for every shop car. We make tie-down hooks (below) for the rear of the S197. But the kit (shown above right) that Ford makes for the S550 looked good, so I bought a set.

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The Vorshlag trailer tie-down hooks for the S197 Mustang rear are very handy for trailer towing

I mentioned in my last post how that the Ford M-1700-M kit we tested makes hooking the tie-down straps to the S550 chassis a whole lot easier. For less than $90 it was worth a try. We have pictures to show them - but we didn't install two of the hooks where Ford intended.


So the rear hooks were bolted to the two threaded holes on each side of the chassis, as Ford intended. These are just inside the "lower pinch weld" in front of the rear tires. With two 3" wide straps from MAC's we cross the tie downs and hook into D-rings on the floor behind the car. IT is easy to toss the straps up in front of the rear wheels, grab into these loops bolted to the floor, and strap the car down from behind.

They intended that you do the same on the front, but with so much front overhang and a low front ride height, it is much harder to toss the straps behind the front wheels from the front.

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When we had the car on the lift I asked the guys to drill holes and bolt them to the beefy front subframe, as shown above. These are much closer to the front of the car, but still bolted to something very substantial. Makes it easy to reach under the nose and hook to these locations - at least until we add a splitter. Then we might move them back to the spots behind the front wheel... YRMV.


There is a reason I am sharing this section because the road course lap times on the NOLA 2.75 mile road course our 2018 GT, at both the TNiA test and Optima event (see below), were downright dreadful. I just wanted to make sure that readers understood that A) this was not my first time at this track and B) that I'm not some total squid who drives like Mr Magoo on course! Please indulge me for a minute while I list my bona fides at NOLA... :D


I made this track map from the NOLA Motorsports Park's 2.75 mi CW road course back in 2013, when I ran my first competition event event there in our 2011 Mustang GT with NASA in TT3. The track layout hasn't changed since, except for maybe getting a bit fasterwith some added pavement at the exit of Turn 16 (it used to be grass).

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Before 2013 I got to make a some laps here in 2012 at a BFG tire test driving a Mustang Challenge/Miller Cup FR500S race car (above). I also ran here with NASA again in 2017 in our TT4 prepped BMW 330 (below). So I had a decent number of laps at this track, had two wins in TT4, two wins in TT3, and set a TT3 class track record that was only recently beaten.

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To compare times between our S550 and our S197, let me explain a bit about that 2011 GT's "TT3" prep level in 2013. When we came here then we had just moved this Mustang into the brand new TT3 class. It was on Motorsport shocks/springs, but had pretty crude aero (APR rear + plastic LS faux-splitter), when compared to later seasons. We were on the smaller 18x11/18x12" wheels under stock fenders, only running 315/30/18 Hoosiers (we later ran 335/345 tires with flares). We brought 3 sets of tires to that 3 day race weekend: 295mm street tires we used in rain testing on the Friday before, a used set of A6 tires (which Amy and I both drove on Saturday), and a sticker set of new A6 tires (which I set the track record with on Sunday morning, in my one lap that day).

TT3 track record setting lap in May 2013

That 1:50.535 lap stayed the TT3 class record from 2013 until May of 2018 - a five full years. So I guess my 2013 drive here was one of my better ones, but the car got considerably faster in 2014 and 2015, so it wasn't what a max-prepped TT3 car should do there today. But not far off. We're running this S550 in TT3 class now as well (but on street tires) and for comparison: at Eagles Canyon's 2.5 mile track it is currently 5 seconds back from our S197 best lap there (still the TT3 record, set in 2013), and 4 seconds back from our best TT3 lap at MSR (we held that record in our S197 from March 2014 until March 2018, 4 years). So if you extrapolate the differences from these 2 tracks, I was hoping to run a 1:53 to 1:55 lap at NOLA (I did not). Also, we've set our best laps in the S550 on the wimpy 14" OEM brakes, which are far worse than what the 15" 6 piston brakes should do on this car (which should be worth another 1-2 seconds, even on street tires).


Last October I ran our BMW 330 in TT4 class, on a little 245mm R7 tire and 40 hp down on the class limit (really a TTD car with a wing added), but with decent suspension, brakes, and aero. My best lap of 1:56.029 wasn't a class record, but it was enough to win the class both days - barely. I drove the piss outta that BMW hunting for tenths, eventually clipping the pit wall on the exit of T16 and popping the side mirror off in the process. This BMW needed more POWER to drop into TT4 lap record range (1:54s), but the aero and brakes worked well enough to sneak in the two class wins.


In 2013 I went over to a Delta Region SCCA autocross during the NASA TT event after their final runs, made two "fun runs" just site reading the course (with Mark Council navigating from the passenger seat), and was quicker than FTD (on my second, cone-free run). So I had good luck at this autocross pad, too. All of those "nothing but wins" history at NOLA gave me a false sense of hope of maybe doing well at the Optima road course and autocross competition segments. But we had unknowingly hobbled the S550's brake hydraulics when we added the 15" PP front calipers - we made the already poor 14" brakes even WORSE. I will explain...


Last time I showed how we moved from the non-track worthy 14" inverted hat front rotors and 4 piston calipers to the "normal" vented 15" rotors and 6 piston calipers sourced from Ford Racing / optional S550 Performance Pack. At the same time also upgraded to more aggressive G-LOC pads front and rear, added our prototype front brake cooling package, and installed our front and rear tow hooks. I drove around the block and the brakes "felt fine" in a few 60 mph stops - this was right before we put the car in the trailer to tow 9 hours to New Orleans. I said was not going to get caught without adequate brakes again. The best laid plans...


We thought we were being sneaky and had signed up for the Thursday evening Track Night in America event with SCCA - to get some road course testing in on the same 2.75 mile course that Optima would run. Well many of our Optima competitors figured this out as well, so it was a crowded track event. We showed up at 2 pm, unhooked the trailer, unloaded the car and got ready for a 3 pm driver's meeting and I was on track by 3:30.


All I could muster were some 1:58.1 laps in the first session - uh oh. But well... there was a LOT of traffic, all gridded out of order. The brakes just didn't feel right, and the car would not stop well at all. By the 2nd session I took a rider (Optima racer who didn't know the track) and ran some 2:02 laps, and that's when I knew I was in deep trouble. There's no way this car should be nearly 8 seconds off the pace of our TT3 car! Tires were sliding, hot pressures were only 30 psi, so I bumped them up 2-3 psi.


I was chasing what I thought were setup issues, but it really didn't dawn on me how bad the brakes were until late on Sunday. Why? Well I was running down the faster TNiA guys Thursday and even ahead the GT class on Sunday morning at Optima. I was ignoring what I felt and focusing solely on lap time placement in early sessions that didn't matter.


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Friday we slept in late, then went out to the track at about 2 pm to tech for Optima, installing all of the sponsor decals, and I did their fire exit drill test (actually pretty thorough). Talked to a lot of friends and competitors, Amy and I helped a lot of folks put their decals on, and we somehow stayed out there until 6:30 that night getting ready for the Saturday-Sunday Optima event. Productive day, and we had excellent seafood that night with friends.




Results: https://clubregistration.net/clients/usca/results/overall.cfm?eventID=8666

Now I haven't done an Optima event since 2015 so I was a bit out of practice. There are at least 5 classes now - I'm going to ignore most of them and concentrate on the GT class, which is for 3200+ pound 4 seat cars, mostly made up of Mustangs, Camaros and Challengers. If I talked about all of the classes and friends we had here this write-up would never end.

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Saturday we were at the track early, but we were all rushed. They held the driver's meeting early (still took a long time), due to a 100% chance of major rain later that day.

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Left: 400#/in rates with Whiteline dampers, 19x11/305 RE-71R. Right: Matt's '15 PP1 on R springs/shocks, camber, same wheel/tire

Everything on the schedule that day got compressed down, all to try to run the autocross before the skies opened up and dumped 6" of rain on the track facility in about 2 hours. We got to the autocross course and the GT class entrants (33!) got either 2 or 3 dry runs in before it started to get damp. Since we had no idea when it would start I took a very aggressive first run - but since I didn't walk the course (due to the compressed schedule) I figured that run would be junk. Turns out it was not only my best run, but the best run for all of GT class that day. I even got lost in the middle section, and of course I forgot to turn on the vidcam, because I was so rushed.


I took my 3rd run in the rain, just for fun... and the Optima guys took this driftoro pic and posted it with my own #Jankystick superimposed! Beaten with my own janky stick of doom! :D

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Turns out my fastest autocross run was only 10th quickest overall out of 84 total entrants. The only video worth showing (below) was my wet run # 3, where I was just hooning. In the end I only won the GT class autocross portion by .003 sec, but I'll take it. I'm not that good at autocrossing, just sometimes very lucky.

Next, we got in line for the Design and Engineering judging, where the REAL rain came in. Man it just poured, for hours. People were seeking shelter and the D&E judges took their time.

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Everyone got soaked and we didn't get outta there until 5 pm that night. That's when I found out that my first autocross run was good enough for the win! And this was my first autocross run ever in this car. Dumb luck - but I'll take it. I still felt like my performance in the Speed Stop and Time Trial portions would kill me, due to the bad feeling about the brakes from Thursday (not to mention the horrendous D&E score that we go, which was even worse).


Sunday turned out to be a PERFECT weather day, but my competition results were taking a nose dive. Sunday was the day that I would fall way back in GT class standings. Sure, the D&E judging was a bloodbath for us, in a nearly stock Mustang, but early on I still felt we could beat the GT class on track and maybe score top 5 in Speed Stop. WRONG.



For this Time Trial portion each competitor had four 15-20 minute sessions on track Sunday. It was a little damp in the first session yet right off the bat I was the quickest car in "Intermediate" group in the first session and had the fastest time in GT class. Optima splits the track drivers into 3 groups: Beginner, Intermediate, and Advanced - with different passing rules and safety requirements for each. We haven't had time to add racing seats / harnesses / roll bar to this car, so I couldn't run in the "Advanced" group. As luck would have it, the two Intermediate groups had fewer cars, and once I got gridded closer to the front, the on track traffic I saw in session 1 went away. The "Group" you run does not affect your "class" standings, just the passing rules and who the other cars you are running with.


But as the day progressed over four track sessions my fastest lap time only dropped by a total of 1.1 seconds. All of the GT class competitors that ultimately went faster than me improved their morning best lap times by 3-6 seconds. As the sessions clicked off I fell to 2nd in class, then 3rd, then all the way down to 7th in class. I got beat like a drum!

quick look at "Hot Laps" road course results, by session

On a positive note, I got slightly quicker each session, but I was only finding tenths. Obviously my times got swamped by 3 full seconds, with 7th out of the 33 cars in GT and 20th overall. Just a dreadful result for how I've done here in competitions in the past. To compare, my best lap was a 1:56.867 which was 6.3 seconds slower than my 2013-seaon TT3 S917 and still a second slower than my BMW 330 - which had over 200 less hp and was on 245mm tires. At the MSR-Cresson 1.7 mile course with the crappy 14" brakes my S550 lap is 3 seconds faster than my 330 - another indicator of how far off the pace this Mustang is with botched brake hydraulics.

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Watching the video below showing my 2 laps in session 4 of the "Hot Lap Challenge", you can hear me complaining loudly about the brakes as I was struggling to get the car stopped. The g-traces look good laterally (1.25 to 1.3g) but in braking the best you see is a brief spikes of 1.05g then it quickly trails off to .8g stopping. The tires were doing their job but the brakes just couldn't load them up. I was braking 200 feet sooner into T1, 100 feet sooner into T13, etc.

The brakes never felt bad, it was just that the car was just not stopping. The harder I pressed the pedal, however, it stopped ever so slightly better for a brief moment - to the point that I was using my entire upper and lower body strength trying to pull up on the steering wheel and press down on the brake pedal SUPER HARD to eek out a tiny bit more stopping power. You cannot do that level of effort and concentrate well on driving, so in the g-traces you can see that brief spike in braking g's, then I would slowly ease into turning then onto the throttle on exit. Too slowly - it looks like some coasting in there, plus the fact that I'm not on the gas when I am still having to brake hundreds of feet early.

The result was that the 14" brake master cylinder was putting too much hydraulic force bias into the rear brakes, and the ABS was pushing back against rear lockup. This made the rear tires also dip into oversteer at corner entry, which I comment about several times in the video. With so much energy going into the rear brakes it is no wonder the tires were getting overworked out back.

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Somebody driving 7/10ths of a car's potential on track might not even notice it, but they'd be 4-5 seconds off the ultimate pace of the car if it had good brakes, just like I was. To do all of this upgrade work - bigger brakes, new pads, brake cooling, drive 9 hours to this event - only to make the car slower, kinda sucked. And of course it had to happen at the televised Optima series event, and not at a local test day (we had no time). I doubt the interviews that were filmed (after my autocross win) will ever be seen on the TV series that follows this series, due to my poor overall performance. But that's how this works - you don't get on TV when you finish 10th, and you don't test new setups at big events. I know better!



As you can imagine, the brake intensive "Speed Stop" competition times were even worse. If you are look at the times for my left and right side course it doesn't look that bad, but it really was. My 11.2 sec (left) and 13.7 sec (right) runs were each about a half second per side off of the GT class SS winner Chad Langley's 2018 Chevrolet ZL1 times of 10.8 / 13.1 seconds. But that's an eternity, and I was buried down in 9th place in class and 26th overall in Speed Stop. I'm not even showing any video of that hot mess. I had great launches, and the slalom speeds / lateral gs were great, just no stopping power.


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My overall GT class standing (10th place) was worse than any of my individual competition finishes due to the horrific D&E score (car show stuff) the car received.

Because of how they score the overall points, even if I had taken first the road course and speed stop and autocross, I wouldn't have won GT class. It all comes down to D&E judging - but hey, that's part of how this series works, and I get it. It still didn't make it sting any less to barely finish "top 3rd" after starting out by winning the autocross portion.


Overall the Optima/USCA folks did a stellar job running this event, and we STILL had fun for the 4 days we spent in New Orleans. Considering the flash flood they had to work around, it was quite amazing.


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Getting to see my nephew, niece, and grand nephew (?!) while we were in town made it that much better. I also got to see a LOT of friends who run Optima events and/or have similar shops to Vorshlag who I hadn't seen in a long time. I'll be back, Optima. And I will have brakes!


One person online had warned me that the master wasn't right for the 15" PP  brakes, while dozens said otherwise. I listened to the wrong people this time. The day I got back from Optima, I was hopping mad - at myself - and immediately asked Jon to order a 2018 GT PP1/PP2 master cylinder and booster.

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In my last thread update I showed how we moved from the non-track worthy 14" inverted hat front rotors and 4 piston calipers to the "normal" vented 15" rotors and 6 piston calipers from the optional S550 Performance Pack. I drove around the block right before we put the car in the trailer to head to New Orleans. I and made a few aggressive stops on the street and it "felt" fine. That's the problem - the pedal feel in regular street driving is close enough, and I feel that's what people who are doing this upgrade are feeling. But it is moving a LOT of brake bias to the rear when using the 14" master cylinder. The hydraulic math proves that (9% front piston surface area change).

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Of course, as you read above about our NOLA Optima weekend, this 15" brake with 14" master cylinder setup didn't work. AT ALL. I could press the brake pedal hard enough that it felt like I was going to break something - yet the car would just barely slow down. The g load traces under braking tell it all.

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I am not trying to start controversy here, but the on track g-trace data, lap times relative to my other drives at this track, and hydraulic math all prove this out. There is a reason why the master cylinder is different on the base vs PP1/PP2 cars. You can see me measuring it in the accompanying video. Its a big difference. I simply could not make this car stop on the 6 piston calipers pushing with the hydraulic master and booster from the 4 piston brakes.

At the same track in our S197 with smaller 14" brakes I could brake 200 feet later into Turn 1 and 100 feet later into T3, T5 and T13. In the 4th session I did some lead-follows with Matt's 2015 GT PP1 car and he could outbrake my car by 100+ feet on every corner with the exact same wheel and tire, the same brake parts (15" PP bits), and he was even using bargain priced Powerstop brake pads. I was on a better pad on the "same" brakes, the exact same wheels and tires, where only difference was the master cylinder hydraulics.


And when you look at the caliper piston surface area differences, the 15" 6 piston brakes shouldn't have worked without the proper master cylinder from the PP. Some people swear by that 14" hydraulics with 15" brakes setup. Others swear that the backwards 14" brakes work fine on track, too. My theory to explain those statements is this: maybe those people just aren't that fast. Inadequate brakes for one person might be fine if they were pushing the car 50% or 75% as hard. So yea, people driving slower might not notice some of the issues I remark about, but when I push a car on track in "qualifying" type laps, limitations start to become very apparent. I have been doing road course events for 30 years, driven tens of thousands of laps in hundreds of different cars. I am not saying I am better or worse than those that argue against me - just that I have a lot of seat time, data, math, testing and results to back up this claim.

The video above shows the bore measurements of the base 14" brake vs 15" brake PP2 master cylinders for the 2018 model Mustang GT, the two boosters, how we installed them, and even the removal of the "sound tube" and plastic engine cover. The 1.5mm difference in master cylinder bores matches the same relative difference in piston surface area from the 14" 4 piston to 15" 6 piston calipers - which might just be why Ford makes two different master cylinders for these two brake packages, right? Why, you ask, does Ford Racing sell the 15" 6 piston brake kit (M-2300-T 4 wheel or M-2300-V front only) kits without the related Performance Pack master cylinder and booster? That I cannot answer - but trust me, you need the matching master and booster. I am not trying to sell you anything here, just trying to save you grief.


Once we tracked down the right part numbers (they are in the images and videos above) we installed the correct PP1/PP2 master cylinder and booster (thanks to tips from the engineers at Powerbrake, who verified the math) on brake mod round 4, then went back to MSR-Cresson for some brake testing (track test #6, below).

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TRACK TEST #6: MSR-C, APRIL 22nd, 2018

This was an unusual and short test day for us. This was a Sunday "member day" at MSR, so I arranged to go with our tester Jerry, who has a membership. He had a bit of a delay that morning so we did not get out there until about 1:45 pm.


The track had double-booked a Camaro club event to run a few sessions on track that afternoon, so it was crowded, and we didn't get on track until 3:30 - the hottest part of the day. It was also the last member session of the day, so the members that were still there all came out to run at once.

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I took what I have learned from running this car over the previous 2 months and put it into practice - I filled the tank full of 93 octane, to prevent fuel slosh in the high speed corners. I tried to get the hot tire pressures to 35 psi (by starting 30 psi front, 31 psi rear cold). We towed the car out to the track, to prevent any flats or mishaps. And I made it to grid first, to try to get some traffic-free laps early.


Well even going out first, I caught the field still coming of the pits in the middle of my first hot lap. Then I fought for 10 hard laps looking for a traffic-free lap, but the tires were too hot after lap 3. Brakes got the slightest hint of fading after 7 laps but I could still push the brakes HARD. Track temp was measured 100°F, ambient was around 68°F, but I was still fighting tire heat after just 3 laps. 10 laps into this 20 minute stint I dove into the pits, Amy checked brake temps and tire pressures, and the right side tires had crept up to 40 psi! She bled all four down to 35 psi and I went back out on track in the same session for 7 more hot laps. The tires were still blisteringly hot. #500psi


In the end I managed to test the brakes well in this solid 30 minute session, over in two stints, and it told me all I needed to know. The pedal effort required to stop at 1.05-1.10 g was normal. The hydraulic issues were gone, and I only saw minimal fade when pushing the brakes hard over 17 laps.

In the video above I show one of several 1:23.1 laps, but never got clear track when the tires were "in the operating range", so I thought this was why I could not reach the previous best lap in this car here (1:21.9, NASA weekend in cooler weather). Going a second slower than my previous best lap, with bigger brakes, and I am calling that successful? Yes. More on this in Test #8, where I matched these tires again.


These Bridgestone RE-71R tires are made to get up to operating temperature FAST, and they perform best in their 1st or 2nd lap on track. The wear rate is somewhat in line with an "R" compound race tire, too (we have 8 events on this first set and they are wearing thin). We saw the same thing in the Focus RS testing at the same track on the same tires. Do these characteristics sound familiar?

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My suggestion is to treat RE-71R tires just like a Hoosier A7. Minimize heat cycles and run them in very short stints. Get out on track, minimal scrubbing on out lap, get a fast lap in quickly (within 1-3 laps), then come in and let them cool down. The RE-71R really is not a casual, daily driver, lap-it-all-day kind of tire. Its a "200 treadwear" ringer tire. Doing 17 laps in one session on them was enlightening.

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If you do want a "lap it all day" type of tire that is similar but lasts longer... the Hankook R-S4 is your answer. They have a lot of the same sizes as the Bridgestone, are a little cheaper, are a bit slower, but last a bit longer - and can deal with heat better over more laps. #TheMoreYouKnow


Talked to a GT350R owner who was running earlier at this same member day and he was super happy with his Vorshlag camber plates, supplied and installed by one of our dealers Doghouse Performance, located here at MSR. They setup up the car with max camber of almost -4.0° and it has helped him run his best ever lap time of a 1:23, and with a pro driver it has run a best of a 1:21 lap here.

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A few weeks later I saw this image below on the Doghouse Facebook page, from a similar/maybe the same car... :( "We saw this failure on a Shelby GT350R with 2,600 miles on it yesterday. That is a connecting rod cap and bolt jammed through the composite (plastic) oil pan. Zero missed shifts. Car lost oil pressure then died instantly with zero warning."


These Voodoo 5.2L engines have a good bit more vibration than the Coyote 5.0L due to the weird 180° fire crank. We are hearing about more and more oil pressure related failures, for sure. Even pro racer and test driver Randy Pobst has come out publicly about the issues with the Voodoo V8. If you own one just make sure that oil filter stays tight and doesn't fall off, people! I would check that literally before each session.

NASA AT COTA, MAY 5-6th, 2018


After a two week break, we were off to COTA to race with NASA on the big boy F1 track! Super excited, and while I have run here 3 times previously, I have only run COTA once in competition. After track test #6 I was at least semi-confident in the 15" brakes now, but could they stop well from 145+ mph, lap after lap? Also, could a 3950 pound street car on Bridgestones hang with race cars with max aero and Hoosier A7s? Well... don't hold your breath. :D


We got there on Friday mid-day, in the pouring rain - nobody got any decent testing that day, due to lightning that shut the track down for most of the day. Glad we didn't spend the $500 for that Test-n-tune day.


We unhooked the trailer, unloaded the car into our garage space, then busted outta there. Met up for a nice dinner at Javier's Tex Mex with a lot of racer friends, near the airport where all of the hotels are.



Early 6:40 am meeting for Instructors and then a TT meeting at 7 am. TT was out on track first and it was still wet - and I was SLOW running some 2:44 laps, trying to remember the line in a car I had never driven here. My BMW 330 lap times from 2017 were in the 2:42 range, which has now held up as the TTD track record through this weekend - somehow.


The track layout was different from 2017 with the removal of the big yellow curbs (sausage curbs) at the exits of Turns T11, T12, T19, and T20. The track limits for TT were also reset out past the second white line (which was past two sets of gator teeth curbing and big green painted patches). This change in limits could be worth 2+ seconds over last year, when we had those curbs to keep us in-bounds and away from 20+ feet of paved runoff.


I gridded for the first session in 14th, and then worked my way up the grid from there. After driving all four TT sessions and even an HPDE4 session, where I took my first student around for some coaching laps, I managed a best of 2:34.693 lap in TT competition Saturday. My first HPDE student Chris had a 2016 S550 Mustang GT automatic - and he had also just done the 15" PP brake upgrade without the PP master/booster. We noted significantly longer stopping distances than my car, but he was also on Hawk pads running about 15 sec/lap slower. Again - not everyone is going to feel the need for the correct master cylinder, but it does matter. His automatic trans equipped car never went into limp mode, and he was relatively quick for DE1. He was signed off for Solo in DE2 later that day I ended up working with 3 more students over the weekend.


The brakes on my 2018 felt "fine" all day. Sure, I could fade them after 2 hot laps in a row with some 145 mph stops going into T12, but with no way to cool the rears (they get HOT!) it is what it is. With Amy and I double-driving the S550 in warm weather, it puts a heck of a heat load on everything. Out of 7 cars in TT3 I was 5th fastest Saturday, and the only one on street tires. There was a LOT of traffic and I fought all day to move up the grid. Frustrating, and I never got a clean lap that day due to heavy traffic and tourists.


In Time Trial group we often get some folks who some of call Tourists. This includes anyone running in TT without a care for the actual TT competition going on around them. See, we often get W2W racers who pay an extra fee (about 50% of the normal entry fee) to be able to jump into TT sessions for "practice laps". They could be super fast cars, but without a previous TT session, they have to start at the back of the grid. The really fast cars then blast their way up through everyone and muck up everyone's laps. Another type of "Tourist" is when a TT drivers take passengers in the TT group. This is somehow allowed in this region, but it is something I don't like to personally do - since TT drivers are allowed to run in HPDE4 group it is always better to take students or riders along there. These TT Tourists might start in the back and drive fast thru the field or worse, or start in their grid spot and drive slower than normal. This REALLY isn't the right way to do this, and I need to talk to our TT director and NASA Region director about working out a change. With 63 cars in the TT group it was crazy crowded.


I had one Tourist in a prototype pass me in the esses, when I was on a hot lap, and he almost body checked me - so I drove off track and over one of the BIG curbs to avoid a collision. Bent a wheel, really torqued me off. Nothing seems to happen to these guys even when we complain about it. I think Time Trial competitors are put somewhere lower on the list of priorities than W2W racers - even in the TT sessions. We had 63 cars run in TT that weekend, often all in the same session - which was massively over-crowded, which led to crazy traffic. But I digress.

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In this session this same prototype Tourist passed me in the same esses - and I had to drive over a curb to avoid him!

I am sure there are some things I needed to apologize for - and I did, in person, to two TT drivers. There were a couple of folks who I held up and another who I passed "briskly", likely in frustration. With plenty of power and brakes for the straights, but lower cornering speeds than "slower cars" on Hoosiers with aero, I was often "that guy" holding up "slower" cars in some corners. I tried very hard not to be.


It took me all day Saturday and even into Sunday to move up the grid to be in the "right spot" where I could get a clean lap without holding up someone or being held up by cars gridded ahead of me. I tried to not blast by a slower car right before a series of corners, and instead waited until a straight and get them under power, or right before a straight and get them under braking. This car stops well and eats up a straight better than most, but the cornering... not quite up to Hoosiers+Aero level yet.


On Sunday I was gridded around 20th and in my first session, but still moving up and down the grid depending on my times and others'. I ran my best lap of a 2:32.7 on my AiM Solo timer (2:32.9 on AMD loop) on lap 4.


Never lost brakes but I got them VERY hot into T12 and T19 where I had to press hard to get the car to make the corner. We measured some rotor temps after a cool down lap of 600°F up front. Yes I am already complaining about brakes with 6 piston 15" Brembos! :D Just got so spoiled last year running the Powerbrake BBK bits on both my 330 and our FR-S, neither of which ever missed a braking zone or faded - they worked flawlessly, lap after lap. Soon.

This shot of me is still within "track limits". We were allowed two wheels past the white line that was past the green section?!

We had some TT guys sessions DQ'd for passing under yellow, and had a number of HPDE and TT cars "have rapid deceleration incidents with stationary objects" (aka: tag walls). It is hard to imagine how you find a wall at COTA, where most corners have 200' of paved run off, but some folks did. Maybe it was the liberal track limits + many missing yellow curbs? Some snap spins to the inside of corners? Whatever the reason it was another reminder that I HAVE STOCK SEATS/BELTS/NO HANS in this car.

My best lap shown in the video above was far from perfect, and there might have another second or two in a "golden session" with this setup and no traffic or mistakes. As you will see, I missed a 2-3 upshift right as hot lap 1 began - in typical MT-82 style - that cost me a position. Then I had to fight to get that spot back on lap 2. Lap 3 was when a Tourist passed me mid-corner and blew that lap, so it took until lap 4 until I put my best in. Brakes were pretty toasty on that lap, tires were boiling, and I was running out of stamina myself (damn this car needs seats/belts!) Rotor temps were 600°F+ after cool down lap.

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Braking into T12 goes from 145mph down to 42 mph, and on lap 4 it was barely pulling 1.0 g sustained there (in previous laps it could touch 1.1g). I think this is just a limitation of the OEM brakes and a lack of any possible rear brake cooling. That's still remarkable, as I was running at 3950 pounds with fuel, driver, and car. Likely the heaviest car on grid.

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In that first Sunday session I ran my best of the weekend with a 2:32.930. I was almost ten seconds slower the TT3 winner that day, my friend Paul Costas driving the cheateringest cheater buggy C5 Corvette, with max aero and 345 Hoosier A7s! :D

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Paul demolished the old TT3 track record (5 seconds) and gave me a reality check of where we need to be. His TT3 times were often 1st on the grid, when the TTU classed Ginetta didn't show up.

This Ginetta prototype with LS power was FAST AF! When it was on track, get outta the way - 2:09s!

Costas was beating all of the TT2 and TT1 cars for much of the weekend, until a few TT1 cars stepped it up. That's a C5 Z06 at 2900 pounds and only 288 whp... "allegedly". ;) Whatever the case, to run a 2:22.915 lap he had to drive the wheels off that C5.

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Its nothing radical - just a gutted C5Z with some big Hoosiers, nice brakes, good suspension, and aero. Sure, it has some hidden prep, but it looks like a sow's ear and yet it cleaned everyone's clocks. So... don't judge a book by it's cover! This is a fleet car at G-Speed that you can rent and drive at MSR-Cresson.


Amy got faster all weekend after I coached right seat with her in 2 sessions. It was nice to see my three other students improve as well. My Sunday 2 sec improvement pushed me up the grid and into 3rd in TT3 class, only 1.3 sec off of 2nd place. Does 3rd place seem like a weird thing to celebrate? Did I choke? Drive poorly?

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I drove my ass off and happily took that 3rd place trophy, got on the podium, popped the cork, then drank ALL the champagne (2 bottles!) that hot afternoon! I was just ecstatic to be able to sneak my way into 3rd place on street tires - in a fat ass street car running against a bunch of race cars with aero. Damn right I was happy.

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Of the three student cars I rode in - E92 335i, S550 GT, and 6th gen Camaro - this 6th Gen Camaro 1LE above was by far the most impressive. HPDE1 student driving it in bone stock form was really hustling around the track. We did a 26 minute long session and the car never gave us any grief - brakes, fluids, tires stayed cool in the heat of the end of the day (88°F). I suspect this car on these MSC2 tires could have given our 2018 GT a run for the money... it was quick. Owner said it does gobble up consumables at 3600 pounds, just like the Mustang does. But with so many coolers it doesn't overheat.

Our car was getting into "limp mode" after just 3 laps - it happened twice to me on Saturday - from high oil temps. Amy ran 4 sessions, I ran something like 7. We would use about 5 gallons of fuel per session but no oil was consumed.


Even having to deal with massive number of cars in TT and the Tourists, it was still a hugely fun weekend. 400 entries in W2W, TT and HPDE was a new NASA Texas record. I was really sore - gotta get some seats and belts in the car, because with 1.3g lateral spikes and these crappy seats, it takes ALL of my upper body strength to stay upright, steer, shift, and mash pedals. And we need more brakes. And more power. And more grip and aero! ;) We did OK relative to American Iron - a W2W class with pony cars running that same ratio on R compounds and aero. Our 2:32.9 lap time would have been 2nd fastest for AI on Saturday and 3rd quickest on Sunday. We will keep an eye on the AI lap time comparisons, like we did on the S197 when we ran TT3.

With engine oil temps spiking after 3 laps we need to look at a better radiator + oil cooler upgrade soon. Trans and diff are silently boiling as well, I fear. Lots to do.


So for the previous 4 events we have been chasing a noise, that is obviously a parts issue. We went to this event in the Mustang to try to verify if we had it fixed, and also to see if we could find the 1:21 laps again here at MSR Cresson.


Amy brought her FR-S out just to make some laps. She knew the car wouldn't be competitive on the 215 Firestone tires that have aged out, but it was her last event on this tire set - as we have 18x11" wheels and 315 Rival-S tires going onto this car this week. Wait... what?! You think I'm kidding about adding 4" of wheel and +100mm of tire to each corner? Think again. Can a 2634 pound car with 200 hp use a 315mm tire? We will see soon... just testing the limits of our "big tires are always better" theory. ;) I have a 6 year long build thread covering this car, of course.

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I drove the 2018 Mustang GT at this SCCA Club Trials event also to compete - turns out we had 10 cars in the "Street Prepared" class I got lumped into somehow (SP allows Hoosiers yet I was on street tires??). I ran the Mustang in 3 of the 5 sessions, drove the FR-S one session, and rode along in EIGHT sessions with either students (and I didn't even sign up as an instructor, LOL!) plus coaching over radios in the right seat. Long, exhausting, hot day... here's my best lap.

The key word here is "frustrating". I ran the same damn times in all three sessions, which matched as my last test here (April 22), but was still a second off our pace using the small stock 14" brakes in March! I have been trying to rationalize why we have lost a second of pace since then, back when we had a ONE LAP WINDOW of usable brakes on the bass-ackward 14" inverted hat, easy-to-overheat base rotors.

Our S550 Lap Times at MSR-C 1.7 CCW:
  • Stock 2018 GT laps March 2nd, 2018 -
  • After Round 1 of mods, March 10-11, 2018 -
    (1:21.9 on AMB loop)
  • After 15" brake upgrades, April 22nd, 2018 -
  • SCCA Club Trials at MSR-C, May 12, 2018 -

This consistent 1 second slow-down, two events in a row here, has verified to us that something has been wrong with the car since shortly after that March event. What I haven't been mentioning in this thread are some issues we have been chasing for 5 events in a row - a very persistent noise and a vague handling issue that has been a real bear to track down. Many components have been removed, re-torqued, and even replaced, yet it still persists. We still haven't definitely proved that a part is "bad" but we will know soon when another major component is swapped out. Until then, just know that this consistent slow-down at our MSR test track has not gone unnoticed. Due to some outside factors (shop move, explained below) we haven't had the time or resources to attack this quickly.

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Left: Street Prepared class results. Right: Overall results

Even being 1 second off the pace from March, we still won SP class with 10 cars, and had the 8th quickest time out of 57 Club Trials entries. But I was still not happy with the lap times. I ran almost the same times in each session, consistently. Session1 - 1:23.079, Session 2 - 1:23.124, Session 3 - 1:23.148 and 1:23.038. Sure, there was some traffic that forced my best laps in the first 2 sessions until after lap 4 or 5, but not on session 3. That time we were gridded by lap times and I built up a gap on the out lap to the 3 faster cars ahead, which yielded 3 clear laps. Tires are still pulling 1.25g lateral in sections, so they aren't totally dead (but they are far from new, after 8 race weekends). I'm driving the same lines, and running consistent times. Something just seems "off".


Very, very frustrating.


I better wrap it up here, as this update has run long. But for once we are caught up on events! We skipped all of the events we had planned to run in June and July, due to obligations every waking moment working on construction of our new shop, moving our business, getting things operational, then continuing construction while we are moved in. Absolutely not the right order of operations, but one contractor was so late wrapping up (8 months late) that it threw all of my plans out the window and put all development work (including this S550) on hold for more than 2 months.


We have been shipping orders for over a month and the shop is operational, but the '18 Mustang continues to wait patiently while we tackle some higher priority customer jobs that were delayed by the move. Because of this persistent lap time slowdown "issue" we have opted to not run the car again, even when we had a few hours on a weekend available and it was a local event. Until we can "fix" this glitch, it is parked.

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As more systems around the shop come online and customer cars are catching up, this S550 hiatus should end very soon. We have a prototype 380mm/6 piston Powerbrake front brake kit already on hand that needs to be installed and a few loose ends completed before that goes into production. That will need to be tested on track. We also have Sparco racing seats sitting here waiting for install - which we will do with production level seat brackets made with our newly added CNC plasma table. A whole new suspension setup is also sitting by, ready to to be tested (MCS Remote Doubles!) But until then, thanks for reading.

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Project Update for October 5th, 2018: Lots to cover since our last post. Due to customer obligations we did not have a chance to order parts and install these updates on our own S550 until the WEEK before NASA National Championships, so we did what say to never do - last minute updates with zero testing before a big event!

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There were also delays due to the sequencing of production testing for some new parts we have been working with, like the Powerbrake 380x32mm rotor / 6 piston Motorsports front brake kit. At the same time we installed a different set of coilovers (MCS RR2) - and we have more sets to test next. We also developed a production S550 bolt-in 4-point roll bar, seat bracket for a Sparco Circuit II seat, installed a new Schroth 6-point harness, and threw on a set of 315mm Hoosier A7s. Most of that was only wrapped up the day before NASA Nats. Yikes!


But I was excited to get back to COTA - so let's dig into Round #3 of mods to our car, then cover NASA Nationals and the short list of updates after.


Brakes: for cars used on track, this is the most important system on the whole car. We started with the base model GT, which comes with CRAP 14" front brakes. We then spent some time testing and upgrading the brakes to the 15" PP fronts. Now we wanted to go further...

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Left: Base model 14" front inverted hat brakes. Bad. Right: 15" 6 piston PP brakes were next

We have covered our extensive struggles with the base model inverted hat brakes. We wiped out brand new OEM front brake pads in just 8 laps, down to the backing plates. Then we tested two G-LOC compounds up front (R8 and R16). With aggressive driving I could still fade the front brakes in one lap. ONE. LAP. It was all the rotors' fault, so we upgraded to the Performance Pack 15" dia 6-piston brakes and new G-LOC pads. With 4" brake cooling, since that 15" rotor isn't made bass-akwards. Those worked much better. If I didn't know any better I would have thought this was "as good as it gets".

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But I do know better. I've been spoiled with Motorsports level brakes on two of my own track cars for the previous 2 years. Our BMW 330Ci got a Powerbrake 340mm x 34mm 2-piece rotor and large 4 piston caliper front kit, shown above. I used the same set of front pads for 2 years - and they were still good for another year!

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Our FR-S has the Powerbrake 325mm x 28mm 2-piece rotors and 4-piston caliper front kit. Still on the same pads 2 years later also. The difference in feel from the best OEM calipers to what these cars have is enormous. Side note: we did spend some time during the 3 month break between these S550 posts working on our FR-S, installing then track testing 315/30/18 Rival-S tires on 18x11" wheels with giant flares. #BigTiresMatter You can read about that in this linked build thread.


We knew before we even bought this 2018 Mustang that we wanted to help validate a new Powerbrake kit for the S550 chassis. We have worked with this company to develop and test 350mm 6-piston kits on SN95 & S197 Mustangs and C6 Corvettes, as well as our BMW and FR-S shown above. With the weight and power of this S550, Powerbrake wanted to use a larger 380 x 34mm 2-piece rotor kit to go with their X6EL 6-piston Motorsports caliper (shown above).

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There are many benefits to upgrading from OEM brakes with 1-piece iron rotors to Motorsport bolted billet calipers and 2-piece rotors. Caliper rigidity with the thru-bolted construction stays stable with higher temperatures. Staggered bore, stainless, vented pistons can be designed to promote even pad wear (no tapering). The 2-piece floating rotor style prevents coning ("warping") as the iron rotor ring heats up, and the aluminum hat keeps weight down.


The weight difference can really add up. On our BMW E46, the weight drop for the front Powerbrake kit was 4 pounds, with a MASSIVE increase in caliper and rotor size. On our FR-S the PB kit it was 9 pounds lighter than stock, also with a substantial increase in both rotor and caliper sizes. On this S550 Mustang, the weight drop from the entire 15" PP brake package (14.26 lb loaded calipers + 34.12 lb rotor x 2 = 97 pounds) was 21 pounds going to the Powerbrake kit.

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Left: 15" PP rotor = 34.12 lbs. Right: 380x34mm Powerbrake 2-piece rotor = 24.4 lbs

A good bit of this weight drop was in the rotors. The 14" inverted hat front rotor was 28.4 pounds and the 15" PP rotor was 34.12 pounds.

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The rotor rings are replaceable, which saves costs in rack consumables down the road. This was us installing a replacement set of rotor rings going on Jamie Beck's ST2 Mustang that has 350mm Powerbrake 6 piston fronts - after a season and a half of racing!


After the PP master cylinder and booster upgrade, and with 4" of brake cooling forced inside the hat of the front rotors, the 15" OEM Performance Pack brakes worked admirably. But again - I had two other track cars at the time with Powerbrake BBKs, and I knew what that difference felt like. The data logged braking on the upgraded OEM 15" brakes was better than the base 14" brakes, just not stellar. Not what I'm used to anymore.

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One week before NASA Nationals we installed this prototype Powerbrake big brake kit to our 2018 GT. We had to make a custom front brake flex line, but we have shared that info with Powerbrake and it should be in the production S550 kit by the time you read this. We also trimmed up our prototype S550 front brake cooling backing plates, just slightly, so that this can now work with the 15" PP brakes or the 380mm Powerbrake kit.


After bleeding the system with fresh RBF600 Motul brake fluid I was eager to test these on track, but our compressed build schedule would not allow for a dedicated track test - we'd be testing at Nationals!


We ran 7 of the first 8 events on the Whiteline monotube inverted coilovers. This was something they asked us to test, as we have a long history working with Whiteline. We had good results and ride quality but by the time we got them on the car and on our website for sale, the deal with their supplier went away, and we had to stop offering that setup. After that we ordered what we had originally intended to use for the long term with Hoosiers - these MCS Remote Doubles, which we call the RR2 model.


We paired these dampers with Vorshlag S550 camber plates, some of our prototype spherical rear shock mounts (more on that later), and one of 3 tested sets of Hyperco springs we spec'd for this application. The spring rates we chose are our "middle" set: 600 #/in F, 750 #/in R. We call this our "GTS" rates, with the GT rates being softer and GTR stiffer. We ran the softer GT rates (400 #/in) on the Whiteline set and still noted some body roll and dive, so we wanted to see the difference on the MCS set, which would only be amplified by the upgrade to stickier Hoosier A7 tires.

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Unlike the inverted Whiteline and Ohlins kit for the S550 chassis, the front MCS strut is a traditional (non-inverted) 22mm shaft monotube with the Rebound knob at the top of the shaft and the Compression knob on the remote canister. The rear damper is in fact an inverted setup, also using a 22mm shaft monotube with the Rebound knob near the lower "T-bar" mount and the Compression knob on the remote. This was the first inverted rear MCS we had run in anger, and we have passed on a few suggestions that MCS has already incorporated into their S550 shock.

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The installation was pretty straight forward, but as you can see the strut stem and knob would be pretty close to the edge of the strut tower opening - and in fact will limit camber travel. The Whiteline was an inverted front strut, which has a super short upper stem and the knob at the bottom, so that constraint wasn't an issue. The top mounted knob on the MCS makes for easier access, but the S550's small strut tower opening (only 1.8 inches - more on that below) made it to where we left the knob off for the COTA event (we ran out of time to modify the towers). I was able to make Rebound adjustments with the small Allen wrench supplied, using the holes in the upper hex portion of the adjuster.

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These went on the car on a Wednesday, and we loaded up for our trip to NASA Nationals on Thursday night. To call this "rushed" would be an insult to the word "rush", hehe. No major issues noted in the two test drives I took in the car that day, rode fine and we set the knobs to about "halfway" on rebound and compression both.


Most folks know that we make roll cages. For a dedicated race car that's all I want to have protecting me anymore. Of course our 2018 GT is very much a dual-purpose street/track car. For that situation a 4-point roll bar makes for a safer setup on the street (no rooftop door bars near an un-helmeted head), yet still gives us some rollover protection and a GREAT place to hang some shoulder harnesses from, for use with a fixed back racing seat and 6-point harnesses. I have been really missing those safety items in this car.


In the past we have used the Maximum Motorsports 4-point roll bars kits for the S197 chassis, with some key options picked. But its no secret that I haven't been too happy with the bolt-in roll bar options available for the S550 Mustang chassis (and Maximum doesn't have one for the S550, as of this writing). We looked at 4 different options and found things we could improve on all of them. If it looked like we could improve on the options out there we agreed that it could be a new production part from Vorshlag.

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We started by removing the front and rear seats and all of the rear interior panels. I wanted a "clean slate" to look for good factory bolt holes to key the roll bar off of. We also looked at NASA Club Codes & Regulations for material requirements, bar routing, angle suggestions, and other engineering aspects for W2W roll cages (that we applied to the "half cage" that we built).

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After copious scraping of seam sealer from some key areas, Jason (engineer), Myles (new engineer/CNC guy), Evan (fabricator) and I all brain-stormed some ideas using the best methods of attachment we could find in the back of this chassis. I had a few requirements that I would not budge on: a fully welded assembly (no post-delivery welding!); a diagonal in the main hoop; use 1.75" x .120" wall DOM tubing (not drag race tube specs); the main hoop kept tight to the roof; and a recessed harness bar for use with taller drivers.

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After some iterations in cardboard, I was happy with the landing plates for the main hoop and rear downbars (the "4 points" of this roll bar design). We transferred the cardboard templates into CAD files, then using our new CNC plasma table, cut out plate steel in two thicknesses over 4 revisions before we had the "base plates" and mounting plinths built to our liking.

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Unlike the S197 chassis that has a replaceable corner section for the main hoop to land, we made these that bolt into the chassis and nest over top of the OEM bits here. This puts the main hoop at the optimum location for the tallest part of the roof, close (but not TOO close) to the driver, and as wide as possible.

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Once the main hoop was bent and trimmed it was fit snugly into the car (with the interior roof panel in place - it's touching). Then the diagonal, harness bar, and rear down bars were tack welded in. It was removed and final TIG welded. The main hoop was routed to clear the OEM shoulder harnesses, so a dual-purpose car (like this) can use the stock belts for street use. Much safer that way.


The completed roll bar was installed for the final time before we moved to other systems. It sits on the rear seat bulkhead and just rolls back onto the rear seat belt mounting studs and holes. Two holes are drilled in the chassis at the rear down bar mounts (4 bolts per plate) and we could have slipped in the rear interior panels and given them a trim, but I'm going to see about that soon.


No, there are no provisions to install the rear seats or seat belts. Why? Because that is silly - nobody should EVER ride in the back seat area with a 4-point roll bar installed inches from their face. As you can see 62 pounds of back seats, belts, hardware, and interior panels came out and about 58 pounds went in with the 4-point roll bar. A net loss of 4 pounds while adding some safety.


At least now I can have some place to mount shoulder harnesses, and feel safer in this car than before. We ran the bar in raw steel for COTA but pulled it out when we returned for powder coat. Next up in our last week thrash... adding a racing seat!


If you have read my posts on other build threads you might know how much we dislike most of the "bolt-in" seat bracket kits out there on the market. I've yet to see one that I really liked. They tend to be weak, sloppy/floppy, poorly fitting messes. I talk at length about seats and mounting challenges in this forum post.

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The base "300A" interior GT 6-speed we got stickered for $36.6K retail. Of course the base seats are COMPLETE GARBAGE, and we thought about upgrading to the "$1595" Recaros. Those work fairly well and would be a great option - if they weren't $10K! Yes, go to the FORD website configurator or click the top right pic to see this: you have to upgrade a bunch of packages to be able to buy the "$1595" Recaro seats, which is how it becomes a $10,095 seat upgrade! :D

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Remember back to my original post about why we purchased a base GT? We wanted to avoid a bunch of useless fluff that would be replaced with better parts in our quest to make the "GT3 RS" version of the S550 Mustang. For less than the "$10,095" price for Recaros, we can damn sure pay for some fixed back racing seats, real harnesses, and a roll bar - just like the GT3 RS has.

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pics of the seat brackets we made - with production in mind - for the late model Audi R8

This time instead of fabricating the brackets one-off we wanted to make a production worthy unit, like we did in this Audi R8 V10 last year. For that car we made a 100% bolt-in seat bracket that fit the carbon tub of that chassis, had provisions for the lower 4-points of a 6-point harness, had a bracket to hold the OEM seat belt lower buckle, allowed for the use of a slider, and made the seat install easy.


That setup worked VERY well in this 2017 R8. Weirdly enough the car was wrecked HARD at COTA later that year, and our harness bar + seat brackets + harness mounts held up perfectly. Guy walked away without a scratch. #CrashTested

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With our CNC plasma table we could make the S550 "production seat bracket" version 100% in-house. Problem was... the first two iterations didn't look clean as the Audi version we made. Super heavy duty. I mentioned what a time crunch we were in - #NASAchamps was just days away! We had to make this version work for the short term, even if it was a little ugly. Plenty strong and rigid, just not production ready.

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The floor in the S550 has some funky angles, and we used too thick of a piece of steel on this iteration. The prototype worked well, even if a bit on the heavy side and time-consuming to weld up. I could fit my 6'3" frame inside with CRAZY room to the headliner, and the slider allows Amy to move forward as much as 18", so she can drive as well. I'm sitting at least 3" lower than stock. We will re-design this bracket and show the production version later in this build thread.

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We used a single Sparco Circuit II seat with a full halo. Scroth's new for 2018 "FIA 2016" rated belts in red were chosen. We went with the 2" belts to make it easier for HANS use. The seat fits very well, slides back for taller drivers and forward for shorter, has no movement outside of the slider's own, and made for a much more comfortable "day at the office" pulling 1.5 g loading with 315mm Hoosier A7s!



We borrowed a friend's Hunter alignment rack and Evan aligned the car to get -3.5° front camber and -2.2° rear. We were in such a rush we didn't print a sheet.

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We weighed the car earlier that day, right as the seat and roll bar install were wrapped up. We didn't install the other seat because of time constraints, but needed a weight and a dyno to figure out if we would run in TT3 class, and if so how close to the power and weight limit. 3607 lbs with no driver, 3825 lbs with driver and 3/8ths of a tank. We would always run the car full of fuel, which would add +50 lbs, even after some laps of fuel burn.

I was able to get into the busy schedule for a handful of dyno pulls at True Street Motorsports the day we were loading up. Richie made 5 pulls and he noted quickly that the car was hitting a 145mph speed limiter, due to the lower speed rated base model tires our car came equipped with. We had never hit 145mph on track (I just touched that speed at COTA in May, on the back straight) so I didn't know this existed. NASA rules require that the dyno tests are done in 4th gear, which on the 2018 GT's "MT82-D4" transmission is now 4th (from 2011-2017, 5th was 1:1).

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That's why the dyno stop at 6750 rpm in 4th, due to the speed limit. Without re-programming the stock tune, it was what it was. We double checked the NASA dyno procedures and we decided to stick with this, as this is how the car could be dyno'd at Nationals (and they DO dyno a lot of cars there).

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Dyno certification form, Dyno avg whp form, NASA TT classing sheet

With peaks of 443 whp STD / 435 whp SAE, using the NASA average dyno procedure calculates to 417 whp average. I ran the numbers, filled in our TT classing sheets, then ran the numbers again. We were safe for TT3 at 3825 lbs and 417 whp, but only just. To compensate for any scale mistakes or dyno errors, we claimed 423 whp avg (+6 whp) and 3855 lbs (+30 pounds). This comes out to 9.11:1 pounds per whp, and with our modifiers (+0.4 for stock aero and +0.5 for 3801-3900 pound race weight) we came to 10.01:1, p-to-w. We ran even heavier, crossing the scales  after every session at 3860-3876 lbs at Nats.


We ran out of time to have the 315/30/19 Hoosier A7 tires mounted to our only set of 19x11" wheels (for now). So we tossed them in the trailer and hauled ass down to Austin Friday morning, hoping to get unloaded and on track by 4:45 pm that afternoon. We would play it by ear with the weather, possibly running some of the first sessions on the RE-71R street tires... because it was raining. HARD. And the forecast showed much of the same.  

NASA @ COTA - May 2018 Recap

As a quick refresher, back in May we ran our 2018 GT at COTA with NASA. We did that event on the Whiteline coilovers, RE-71R tires, 15" PP brakes, and the track limits for that event were quite open (the large F1 curbs on the outside of T11, T12, T15, and T20 were missing). I ran a best lap of  2:32.9, which I was fairly happy with. That took 3rd place in TT3 class at this Regional TT event, losing to Paul Costas in the G-SPEED prepped C5 Corvette by a massive 10 seconds.

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As crazy as that sounds, the 2:32 lap time was actually pretty good, and would have been the P2 qualifier in the American Iron W2W race field (AI times are something I've always compared our Mustang TT3 times to, as they are all pony cars with similar 9:1 power to weight ratios, full aero, etc). We saw high oil temp problems, traffic/tourist issues, and the street tires were holding the times back a bit, but I finally had brakes that worked - where I saw 1.2g braking into T1 and 1.0g into T12 (after back straight). Cornering was 1.1-1.25g lateral on the 200 treadwear tires.


After loading the Donkey and the Mustang into the trailer, Amy and I blasted down to COTA on Friday morning. We got there around 12 noon but the off site registration had closed, so we wandered into the "A" lot out front. The weather had been bad all week during testing and not many dry laps had been taken until that Friday morning. We didn't pay ~$1M for Thursday or Friday test and tune sessions, and instead would rely on the 5 or 6 TT sessions to setup and learn the new suspension/tires/brakes, running Friday night through Sunday.


Parking was a bit of a thing, with 500+ racers and 70 in Time Trial. The garages sold out ages ago at $2000/per, and even the lower paddock lot was full. So we parked out front in Lot A, near the kart track, outside of the track.

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the distance to the paddock / grid area from Lot A was over a mile and a half, but luckily we had brought the Donkey - our recently restored Taylor Dunn pit vehicle. We drove many, many miles over this 3 day race weekend in the Donkey, staying dry in the rain and honking at everything that moved. Hauling fuel jugs and tires or taking passengers. A donkey is not known for its speed, but it sure beat walking! :D


With zero testing I was to go on track at 4:45 pm for the TT Warm Up. Raining pretty good, on the street tires. As I drive to grid I realize we have the rear ride height set too low and it's bottoming badly in paddock. Went out anyway, trying to move up from my 64th spot on the 70 car TT grid (they gridded us for the first session based on when we signed up?!) Passed over 20 cars in 3 very wet laps. Car bottomed out a lot, ran a 3:00 lap... terrible.


That night we had some major changes to make. In the dark. And rain. Forgot to bring a good floor jack and nobody around us had one, so we went to a local Harbor Freight and yelled "Sell me your finest jack, good sirs!" ;) Got back, raised the ride height a little at a time until we got about an inch and a half of rear bump travel. Big thanks to competitor Paul Costas who helped us with these ride height changes! Drove each iteration around the very bumpy paddock roads and it was not perfect, but better.

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Snatched the wheels off, took them using the Donkey over to Hoosier, who said they would change them first thing in the morning at 7:30 First in line.


We showed up early at Hoosier (7:15), nobody around. Came back at 7:45, and now we were 5th in line. Another TT meeting at 8:30, then on track at 10:10. We were waiting impatiently at Hoosier and they had all 4 tires mounted and balanced by 9:40. Hauled back to Lot A and went to mount the wheels and tires. "Only 10mm wider" than the 305mm tires we had on there? Should be no problem.

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Big problems. Tires won't even turn, hard stop against struts in front and e-brake cables out back. These 19" Hoosiers are fully 1" wider per corner. YUGE! You can see that in the stack of 4 Hoosiers vs 4 Bridgestone tires, below left. We had to do a mad scramble and add some random 3/8" and 1/2" spacers behind all 4 wheels, which was all I had in the trailer.

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Battery powered impact dies on the 7th wheel change, so we're spinning these lug nuts onto super long ARP studs by hand. We had NO TIME left. I jump into the car (sans driving suit), drive over to paddock, and make it at the 5 minute warning, when they are about to close grid. CLOSE!

I managed a decent first session, ran a 2:37.339 lap on a moist track, only a tenth behind Costas. Good time, moved me WAY up the grid.

2nd session was pissing rain as we went out, I was 24th on the grid, but I went out on the A7s anyway. then I passed everyone ahead of me. I had a blast - this was my favorite session on track of the weekend. Had a 2:51.0 best wet lap. I love racing in the rain, as its when I have always done my best in autocross and track driving. No tread on these A7 tires, but it was still 10 seconds faster than the street tires on Friday. Won't bother bringing street tires as "emergency backup" rain tires ever again. Either bring Full Wets or don't bother.


3rd Saturday session was finally not wet - our first dry session of the weekend, and I ran my best so far. I put down a 2:30.333 lap, which was 11th quickest of the entire 70 car TT field. I was finallyquicker than we ran in May here on street tires (*which had radically different track-out on 4 corners). That moved me up into 3rd place out of 10 in TT3 by then. Costas in the G-SPEED C5 ran a 2:24.948, provisionally had 1st in class, but his time was DSQd (blew dyno). Schotz was quick and really in 1st with a 2:27.559. Our customer Adam B in his EVO X (we had done a lot of safety work to thisd car) was ahead of me in 2nd by 0.05 sec with a 2:30.293. We were all bunched up, other than Costas, but he had dyno problems...

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At this point I felt pretty good about our performance, so we left the car alone and went to dinner at Javi's with Adam and also Danny Puskar from G-LOC brakes - where he had his first ever taste of Mexican food. Like... ever!


Sunday the Championship races were wrapped or wrapping up for the W2W classes. TT had 2 more sessions that counted, but those were each in a "split group" with the faster half of the TT grid in the A group then the slower half of the field in the B. Less traffic with half as many cars on track, and by this point the field had pretty much sorted itself out by times / placement. It was much easier to get clear track this way.

After our 7:15 am TT meeting, I went out in the 8:20 am A group TT session, where it was 77°F, overcast, and dry - our second dry session of the weekend. I spent Lap 1 behind Adam's EVO and and put down a 2:28.980 lap (shown in the video above). Adam started pulling away from me on lap two but I slowed down a half second; he ran his 2:28.4 best. In the B group some TT3 BMW threw down a 2:27 and jumped up to 3rd place, outta nowhere... so I fell to 5th and Adam to 4th.

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The next session was dry but considerably warmer, and almost everyone slowed by about a second. The "golden session" was that Sunday morning early one. That's when 95% of the TT racers put in their best time.


My 5th place time in TT3 would have been 3rd place in TT1 or TTU, faster classes that just had a little less depth in the field. Oh well.

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Podium pics from TT - congrats to all trophy winners!

We went to the award ceremony and congratulated everyone who got a trophy. I don't think any TT records fell - again, everyone was faster back in May. We packed up our paddock spot, loaded the Donkey and the Mustang into the trailer, got on the road by 3:30 pm and were home by 8 pm.

Results Analysis, Issues, and Lessons Learned

Driving in the rain on A7s isn't terrible, unless it is POURING rain. A pit vehicle with a covered top is highly desired at wet events! #TheDonkeyRules
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Oil temps were a real problem all weekend, even more than we have seen before. In the wet I could do 4-5 laps before oil temps got into the red and the car went into limp mode. In the dry sessions it was rare the car could go beyond 2 hot laps. I was taking precautions and not letting the car idle in grid, taking a super tame out lap, and only giving it full throttle and rpms on the hot laps. We have already ordered a new radiator and oil cooler, plus a suite of analog gauges (see below) to fix this.

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The Powerbrake setup was phenomenal all weekend. Super easy to push the car in the wet or dry. Best aspect of the car, even slightly better than forward acceleration, which this motor provides plenty of. Coupled with Hoosier A7s there are several 1.4-1.5 g stops into T1, and 1.2-1.3g into T12. Lateral grip was 1.3-1.4g when I loaded the car up in corners.

Forward acceleration was a little hampered here by the unusual trans+rear gearing - I was never quite in the right gear. 2nd was a bit much and could easily haze the rear tires out of T20 and T11. 3rd was a hair sluggish in some corners. Didn't top out 4th on the massive back straight (touching 146 mph), which is the 1:1 gear, at our fastest track on the calendar?! This MT82-D4 gearing is wacky and we will obviously change the rear gears to a 3.73 or 4.09 final drive soon. We will run the calcs for the tire heights we use and pick the best ratio and re-gear.


The rear suspension was bottoming out in 4-5 corners per lap, even after the ride height changes made Friday night. So I had to drive around apexes and avoid some of the bumpiest sections - that cost me some time. And of course the track-out on T11, T12, T14, and T20 were massively different from the May NASA event, which easily cost us 2-3 sec per lap (most racers that ran both events noted this delta). We could still track out of T19 as much as we wanted, which I always did...

video of tracking me out of T19 behind Costas... maybe that was a bit much, LOL!

Traffic was pretty ugly for the first few wet sessions, as some of the slower drivers in faster classes held up cars behind them. This TT1 classed Audi was particularly bad about blocking, and held me up on no fewer than 3 sessions. Driver was just not aware of anyone around him, at all, and dozens of us complained about him and a few others in the driver's meetings. This sometimes happens at Regional events, but to see drivers with so little situational awareness at a National Championship was odd. Some drivers very nearly got an eventDSQ from this stuff.

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I like the fact that National TT Czar Greg G. held 5 separate TT driver's meetings. It let us give feedback on issues like these blockers, rules situations, flag infractions, and dyno questions. I liked the meeting frequency. Very much favor of this format rather than the "one meeting for the weekend" format most NASA regions run. There were probably 10 people that got session DSQs from our feedback in these 5 meetings - all of which were well deserved. Greg always took roll, so if you missed a meeting and didn't send an approved proxy - you also got a DSQ from the previous and/or next session.

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The National TT rule of "no passing on the first hot lap without a point by" was a little strange, but we got used to it. Some folks had trouble with the dyno but we weren't fast enough to get called up, so it didn't effect us. There were two scales and we were weighed after every session. I had issues on the left scale twice. It read my car 200 pounds light once, 100 pounds light another time. On the right side scale it was always 3860 - 3876 lbs, depending on fuel load, which was on the money. We learned a long time ago to only run this car at a FULL tank, which helped with ballast as well as prevented fuel starvation on left turns. With Hoosiers this was more important than ever.


My first lap was usually the quickest, as tires would get just a tick slower after one lap (normal for A7s). Obviously the 12" wide "315mm" Hoosiers didn't fit the car as we had it setup, and we had to scramble to make it work. You can see that clearly in the "as measured" tread width and section width numbers below for the RE-71R and A7. We've since fixed the spacer/camber issue (will show later in the thread) but I should have invested in another set of (18x11) wheels long ago, and test fit the Hoosiers at the shop (note that the 18" version of the 315mm A7 is $86/tire cheaper than the 19", below). There is a way to fit these 12" wide tires without spacers, but not without a lift and power tools. We have two more sets of race wheels ordered now (MOMO).

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Of course setting up a car with all new EVERYTHING at a National Championship race weekend is the WRONG WAY TO DO THIS. Again, customer obligations forced my time table back to the 11th hour. Which meant I was still learning and tweaking the new setup in the handful of dry sessions we had that weekend, but still managed to close the gap to the #CheateringestCheaterBuggy C5 ;-) by 5 seconds, down from a 10 second gap from our last match-up in May.


The C5 that won TT3 was 2650 pounds (2880 with driver and ballast) and made about 288 whp (tuned down from 480 whp) with a custom "flat power" tune. Costas was often the quickest car on grid, and he put down some damned fast laps. G-SPEED had done some major improvements (Penskes, Brembo Motorsport brakes, rear diffuser, moved up to 335/345 A7s, new motor, magnesium C7Z06 subframe, and more) to this Corvette, dedicated testing and data collection at COTA, and we still caught up 5 seconds to their times. G-SPEED had the motor for this and the TTU winner built by HPR (which I am a small part of) and Costas is a good friend of mine, so I was happy for them. :)

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That 5 second catch-up to Costas was my stretch goal for this event, and we managed to do that as well as outpace the entire American Iron grid (the fastest AI racers ran high 2:29s); they were the closest cars to our Pony car, at this event.

American Iron Champ Race results lap times

At one point our Mustang was 10th quickest on grid out of 70 in TT, in what I am fairly certain was the heaviest car on track, and one of only a handful of street cars around.

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It was a VERY busy weekend here, as we had a crowd at our trailer at almost all times (customers, dealers, vendors), plus we had to park 1.5 miles away from grid, so there was significant time spent going back and forth to drive and for meetings. Next year we will register early and get a GARAGE in the front straight paddock - damn the $2000 cost! I missed just about every W2W race I wanted to watch, being stuck out in lot A.

Adam Baltutis in his TT3 EVO X (at left) and me throwing silly "VM" gang signs in front of our Fat Bastard! (on the right)

The new seat and harnesses worked GREAT! Wish we could have done this sooner. Even with higher g loading my back and arms weren't on fire, like they normally are after a long TT weekend. I wore my race suit in every session except one (where I barely made it to grid, jacking with the Hoosiers). It was hot and humid most of the weekend and I definitely got hot in my suit, so we need to seriously think about a cool suit (note the hoses coming out of Adam's suit, above - we added a cool suit setup to his car). If we add more power we will need the ballast anyway. ;)

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Amy was my rock over the 3 day Nationals weekend - she could have driven on Team Vorshlag but due to the limited number of dry sessions she let me drive them all. She kept me hydrated and fed between sessions, helped with tire changes, took pictures, everything. The weather was a constant challenge but everyone had to deal with it, and we got our two dry TT sessions. There was a little drama, and a car that was handicapped a bit (oil temps & rear shocks), but I was damn happy to run a 2:28 lap in a heavy car, with a bone stock engine, AC, zero aero, and that was still street legal. I used the AC on many occasions!

We had a good time running this National Championship event, and I look forward to running with Texas TT3 guys like Costas in the G-SPEED C5 and Adam in his EVO again next season. :)


We got back from COTA with the big spacers on, and the tire poke was KILLING me. Why does any amount of tire sticking past the fenders matter? Well in reality its not that big of a deal - if you have sufficient clearance at full bump travel. The #CheaterC5 had gone to 335mm fronts (from 315s) between the May and September events, with just cut fenders, and it was still plenty fast.

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Left: #HellaPoke! Right: At full bump travel and loaded in a corner, the outside tires were very close to the fender lips!

But having the tires sticking out past the fender lip can cause tire damage when going over a big bump. Luckily when our car loaded up in corners, the sloppy rubber suspension bushings loaded up and pushed the wheels inboard enough that the outside tires it just barely cleared the fenders (see above). Man it was close!

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Still, going down the straights with a spinning tire sticking out in the air stream, especially the fronts, adds a lot of drag. We often make fairings that blend into the flares/front cover (or even just basic "tire walls") to cover up the leading edges of the front tires - like we did on our TTD/TT4 BMW E46, above. That is something we need to address on the S550, eventually. We may or may not do big aero on this car...

Changing from 1/2" to 1/4" spacers made a big difference, above

I asked Evan to look at the rear E-brake cables (which was where the rear tires touched inboard). Those got bent out of the way (just a few gentle taps with a 5 lb sledge) and now we have 1/4" more inboard rear room (see below left). Then we swapped out the front spacers to smaller 1/4" thick units, and the #HellaPoke is much removed (see above).

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Up front was a balancing act between the strut-to-spindle slotted connection and opening up the strut top hole. The strut brackets almost always has one slotted hole, especially on aftermarket coilovers. We will show how to "fine tune" this interface for the ideal tire clearance + camber in the next thread update. With these splined spindle mounting bolts, it is tricky (above right), but possible.

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I'll show more of the strut tower opening next time, but we made a new series of tools that we will sell soon for the S197 and then another for the S550 towers. These bolt in place of the top mount and line up a hole saw.


We chose a 2-3/4" hole saw and cut the towers on my 2018 GT here. This allows a good bit more camber travel as well as caster travel. With the MCS RR2 struts in place we can kick the top of the strut a lot more inboard now. This allows the strut-to-spindle junction to push outwards for more inboard wheel room to the strut.

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We took the Hoosiers off the 19x11" wheels (above left) - they looked great and should give us another competitive weekend or two of NASA events, with careful tire management. The RE-71R tires (above right) were re-mounted to the same 19x11 wheels again. I had them flipped relative to the wheels, and after 7 events/weekends there is plenty of rubber left. Still has a good durometer number, too.

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We have a few street tire events lined up (to test the Ohlins coilovers we just added), then a NASA event at the very end of October (back on MCS RR2s). By then we hope to have our new MOMO wheels (Heritage 6 in 18x11, above left, and RF-20 in 19x11, above right) on hand, to be able to swap tires and wheels more easily. The plan is move (the next new set of) Hoosiers to the 18x11 set and keep running 305/30/19 street tires on the 19x11 wheels.

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The brakes looked great after COTA. Again, braking was the BEST thing about the car at Nationals. Could always pass other cars into a braking zone, if I needed to. Made a LOT of passes T1, T11 and T12. Temp paint on the rotors and temp strips on the calipers showed that we were in the right heat ranges. The Powerbrake PB13 front pads had good bite without upsetting the ABS tuning in the wet. Going to keep these going on the front for a while. Rears are R16, very aggressive compound, but it's working.

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We have another set of dampers on the car right now, Ohlins R&T, for a track test and some other events in the next month. The MCS dampers are going back on the car for a NASA event in late October, with a few small tweaks to the rears. Will share more of all of that next time.

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Last but not least, we did an oil change. We went from Motul 5W50 to 0W40, at Motul's suggestion. We will try this at our next track event to see if there is any change.


There are a number of items we have shown in this build thread that will soon go into production. Our front and rear S550 tow hooks. The 15" PP / Powerbrake 380mm brake cooling backing plates, and the 2018-19 GT brake inlet ducts.

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We will also heavily re-design our S550 seat bracket kit, and we are coming up with the costs for the 4-point roll bar. Just got that back from powder coat and its about to go back into the car.


A number of things have kept us from making some of these new S550 parts. Mostly suddenly high materials prices - aluminum and steel costs are SKY HIGH right now. I'm losing $1000-2000 a month covering these increases, but I don't want to raise our parts prices yet, since the panic over the tariffs should be temporary.

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We have a lot of other parts coming to test. An S550 oil cooler from Mishimoto will be here later this week and their S550 radiator soon after. Auburn sent us their new 34-spline differential to try, so we will put that into a new S550 aluminum housing with a new gear ratio (3.73 or 4.09) very soon.


Lastly I have a set of 3 analog gauges coming to monitor engine oil, diff and trans fluid temps. I don't trust the OEM data for any temps. These 2-1/6" diameter, 270° sweep, stepper motor, electric gauges are going into a Ford Racing M-6304GPOD-A housing (Boss302) for a dash mounted setup. It should look like the image above. Will show the install of all of that next time.

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We have a lot more plans in store for this car over the "winter" and we will post up again, shortly after the final NASA Texas event of the year. There are many more events for 2018, too. I definitely need to redeem myself after the dismal showing I had at NOLA with Optima back in April, but having functional brakes might help! :D

Thanks for reading,

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Hi Terry, quickie question on this statement:


"Engine oil was also upgraded to Motul 5W50 Ester based synthetic. This lubricant is one we have used on several race cars in the past couple of years and they tend to drop oil temps by up to 30°F. If any engine needs it, it's this one."


30*F drop just from oil? Seems hard to believe. Any more info on that? I recently switched to the Motul 8100 line in my ND Miata HPDE car so I'm interested in this ;) Thanks!

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Hi Terry, quickie question on this statement:


"Engine oil was also upgraded to Motul 5W50 Ester based synthetic. This lubricant is one we have used on several race cars in the past couple of years and they tend to drop oil temps by up to 30°F. If any engine needs it, it's this one."


30*F drop just from oil? Seems hard to believe. Any more info on that? I recently switched to the Motul 8100 line in my ND Miata HPDE car so I'm interested in this ;) Thanks!


That was from data provided by Motul, from a race team that monitors oil temps on a 600 hp Viper. Unfortunately we have not seen a significant oil temp drop on our 2018 Mustang, and have a prototype Mishimoto oil cooler which just arrived about to go onto our car. 

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  • 2 months later...

Project Update for December 29th, 2018: Plenty to cover over in this, my last forum build thread update for 2018! Since the last entry 2+ months ago, we have done 3 more track events. I will cover the last NASA Texas TT event at NOLA (late October), a dedicated test day MSR-Cresson (November) where we tested the Mustang on Hoosiers and RE-71Rs, and an SCCA Club Trials at MSR 1.3 (December).


Several of the prototype bits we showed in previous posts are now in  production, including our S550 rear tow hook, the 2018-19 GT front tow  hook, S550 front brake cooling backing plates and 2018-19 GT front brake  inlet ducts - with more in the works. We even released a new S197 part! Our new shop setup (we moved in June) and some new equipment is allowing us to turn out more new products quicker than ever before.

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We cover the installation of the S550 Ohlins R&T kit. Now that I have tested these on the street and at 3 track events, with Hoosiers and street tires, I have some good first hand opinions of this Swedish built setup. We will also show a trick for adding rear tire room out back for the S550. A 3 gauge pod  install will be shown, plus the Mishimoto oil cooler install - which made a huge improvement to the track abilities of this car.

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We will show what 9 track weekends have done to our original set of 305/30/19 RE-71R street tires. After seeing this, I don't feel they are as delicate as some others say, but we have been very careful how we utilize  these sticky 200 TW tires. #NoStreetDriving


We have also put together a proposal for sponsoring a new Street Tire Time Trial series within NASA Texas for 2019, which I will discuss briefly at the end. Excited to make this happen and hope it brings more new people to come try out Time Trial. Let's get started!


So there are a lot of opinions of what tires and wheels can "fit" the S550 Mustang chassis under stock fenders. We have sold 12" wide wheels to S550 guys, but we always warn them that the tires will stick past the fenders (aka: poke).

This is easily defined as a "past the fenders" fitment, but people still like to argue

And  yes, 12" wide wheels will poke past the fenders on the S550. Ask  online, however, and a dozen folks will chime in that they have seen  people running 12" wide wheels and 335mm tires "with no problems".  Again, these folks live in the KINGDOM OF POKE. We have not seen a 335mm  tire that actually fits under the unmodified fenders of a  Mustang GT. If we felt like we could fit a 335mm tire under an S550  without cutting or hammering, we would have damn sure done so over the  past 4+ years.

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Then there are the "Real" measurements of some tires. For instance, the 315/30/19 Hoosier tire is one big fella, with 12.3" of section width. It barely fits on an 11" wide wheel (above left). In a rush to get these onto our car  during the 2018 NASA Championships with no prior testing, I just slapped a big spacer on each corner to make it clear inboard, and it poked (above right) outwards. Not my proudest moment.

According to tire markings, the "315" tire set (left) should only be 40mm total wider than the "305mm" set (right)

This  giant 315mm Hoosier is so big it would actually be better utilized on a  12" wide wheel, but that would create even those fender poke problems,  so we're sticking with 11" wide wheels for our shop car - for now. There  may come a time when we cannot ignore the 335mm tires for street tire  events, and we do have new front bodywork coming sometime in January  that could help there. I've just decided I don't want to modify the rear  fenders on our 2018 GT here, as that is impossible to "un-do".


After  the COTA Championship event we got back and wanted to remove some or  all of the wheel spacers I added there - in our last forum update I  mentioned that we made some changes for the 315mm Hoosier setup. I have a  few images to show the steps to gain inboard rear tire room on a S550  to do this. This is an old trick we first figured out for the S550s in  2014 but didn't photograph until now.


Watch  the rear e-brake cable for rubbing. The 305/30/19 fit like a champ but  the 315/30/19 Hoosier needed more room... That e-brake cable bracket is  pretty easy to move....


After  a little persuasion we gained over a 1/2" of rear inboard tire room,  and I was able to remove the 3/8" thick spacer added on the back to  clear the Hoosiers. Up front we tweaked some adjustments to the  strut/spindle location, then opened up the strut tower opening, and  managed to reduce the spacer needed by half... but I'm still not 100%  happy with that end.


Again,  this is a non-issue with our S550 19x11" spec'd wheels and 305/30/19  tires (below left), or even our 18x11" wheel spec and 315/30/18 Rival-S  tires (below right). Just an issue when running 315mm Hoosiers - which run really big.

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We are still not ready to make a production run of this S550 bolt-in 4-point roll bar yet, but at least I got our prototype powder coated. So it is not raw steel anymore.

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One of the many advantages of having a real roll bar - other than the  obvious safety aspects - is it gives you a place to mount a video camera  mount. The I/O Port articulated, isolated mount is bolted to the diagonal in the main hoop (below left). With the camera mounted here we can see what the driver is doing better.

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I'm  still researching modern vidcams that have the features I need: remote  start/stop, remote mic input, and a proper FOV lens. My old unit would  work, but its fairly old and the image quality shows. The wide  angle/fixed lens Sony HDR-MV1 (above right) is still being used on a RAM  mount suction cup mounted to the windshield, for the near term. And yes, that is a Toll Tag on the windshield. #BecauseStreetcar


We  have been really happy with the Ohlins R&T shocks that we have  tested and installed on number of customer cars over the years. We  became a dealer for this Swedish monotube adjustable coilover company in  late 2017. They wanted us to try out the S550 kit and sent us a set for  testing - which we installed onto our 2018 right after COTA Nats.


The  main difference between the Ohlins R&T kits and the MCS 1/2/3/4-way  Motorsports shocks are the following: Thr R&T kits include springs  and parts made so that they can work with the OEM top mounts. These kits  often include remote ride height adjusters, when necessary. Its a  complete kit in one box. The MCS kits don't include springs, remote  adjusters, etc. The R&T kits have one knob that adjusts Rebound  (mostly) and compression (a little). They are usually sprung and valved  for street use with some track use. MCS kits are valved for the spring  rates dealers order them for, and can be used on the street (many of our  customers have dual purpose cars). MCS has separate adjusters for  Rebound and Compression, depending on the model. We like to talk to  customers about goals, tires, and uses before recommending one model or  brand over another.

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The  R&T front strut uses a massive inverted strut, which is rigid and  resists deflection under lateral loading. This S550 kit was setup with a 504#/in (90N/mm) front spring and comes with adapters for use with the OEM strut  top mount. Of course we opted for the Vorshlag camber plate upgrade. We did have plans for street and track use, with both the RE-71R street  tires and the Hoosier A7 race tires.

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Out  back these S550 R&T dampers use a non-inverted damper with the  adjuster at the top. The kit also comes with a ride height adjuster in  the stock/divorced spring location. We installed one of our spherical  top mounts for this kit, of course (below right).


There  was a slight challenge adapting this to the 2018 GT rear control arms,  which we have shared with Ohlins - but it was a simple fix. All of this  is covered in our S550 Ohlins R&T installation gallery.

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We  used our shortened Whiteline front endlinks and set ride heights where  we had the MCS setup, about 1" lower than stock. This time I drove them  on the street a bit before we went to our next track event.

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Loading  up the car before this event was somewhat eventful - getting the  trailer unstuck from my property was a mess. We had 4+ months of rain  here in north Texas, which has turned the ground into mush in many  areas. Amy and I left the shop early Friday morning for the "8 hour tow"  down to New Orleans, and of course I got popped by the Popo 30 miles  from the house, in a town with literally one stop sign. Great.

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After  some road closures, crazy detours, crappy roads, and just typical  traffic we made it to the track 10 hours later by 6:10 pm, 10 minutes  after registration/check-in closed. We got unhooked and ready for to  take off as dusk arrived.

Event picture gallery:

Temps  were great all weekend, with lows down to 59°F and highs in the 77°F  range all weekend. The Hoosier A7 tires were used, which had about 7  heat cycles on them from COTA. The Ohlins R&T were out of the box  stock, with their included springs that were a touch on the soft side  for 315mm A7s. Again, this is really a coilover kit made for the street car that sees a few track events a year. Ride quality is  excellent, by the way. They still worked admirably for the grip levels  we were throwing at them.

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We  brought the Donkey inside the trailer with the Mustang, so we had a way  to get around the LARGE paddock area here at NOLA Motorsport Park all  weekend. My niece's son (my grand nephew?) had a ball riding around in  this vehicle all weekend.

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He  also "helped" me fuel the car (with an empty fuel can), "check the  tires", and had to sit in every tractor and race car on the premises.  Thanks to those that let hm sit in their car when asked. He was on cloud  9 with this much machinery around. wink.gif

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I was there for our final NASA competition of the year, and I drove the  2018 Mustang in TT3 class. This set of tires had taken a shellacking at  COTA but I had hoped they would get through this weekend and leave us  one test session at MSR-Cresson soon after (see below for that).


This  is an aero-centric track, with entry speeds into T1 as high as the fastest corners at COTA (145 mph+), and a 130 mph entry into T8, with sustained high speeds through the esses from T9 to T12. Other than the  lack of elevation here, this track is closer to COTA than any other in  the Texas/Louisiana/Oklahoma area, with similar average speeds.

Our car is still a tick under powered/over weight and definitely  under-prepped for TT3, but who knows? I went here hopeful that the car would make some decent grip, I could test out the brakes (when we ran here with Optima earlier this year we had the 15" PP brakes with the  wrong master cylinder), and we'd see if the Ohlins R&T setup worked  with Hoosier A7 levels of grip.


I set the current TT3 record here back in 2013 at a 1:50.535 with a more prepared 2011 GT, but not a max  prepared TT3 car. It had decent power, with a plastic front splitter  and APR wing on sticker 315mm A6 tires. I also spent the Friday before  testing and learning the track, dialing in the setup. I figured our 2018  GT would be 1-2 seconds slower than that more prepped car, but that  might be enough to win the class this weekend.

Saturday - TT Race 1

We  had 7:30 driver's meetings for TT with follow up meetings at 11:30 both  days, which was nice. This "2 meetings per day" policy comes from  changes implemented by NASA National office, which I agree with, as  strange as that sounds.


We  had 5 competitors signed up but only 3 that made it to the event. My  two TT3 competitors all weekend were Bruce Mowry in a gutted E93 M3 with  Hoosiers and Aero (above). He had run the Friday test day and he told  me he had got down to a personal best of a 1:54 range in testing. There  was also a 911 Carerra 4S driven by Joey Dumas - also gutted/prepped, on  Hoosiers with aero. Joey's car lives here at the track, where he is a  member, and he gets a lot of seat time here. Hmm, so scrub cars here - I  might be outgunned.

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Right  out of the box on the TT warm up I got stuck behind a yellow Corvette,  who went off in front of me at T1 in the first hot lap, and then came  back on track right in front of me. Yikes!

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Amy  almost got the picture of this incident... I avoided collecting the  yellow Corvette with a quick evasive maneuver but it ruined my lap and  the session only yielded a 1:54.259 lap, putting me 2 tenths behind  Mowry and 2 seconds behind Dumas.


Saturday  TT session 2 put me into a 1:53.542 best, but the 911 ran a 1:51.669, so I was trailing by 1.8 seconds, but only back a tenth from 2nd.  Saturday session 3 was a lot closer, with all 3 of the TT3 cars running  1:53 laps, less than 4 tenths separating us all, but I was still in 3rd.

I  kept moving up the grid as I dropped time, yet still kept being held up on the first couple of laps each time. These A7 tires "switch on" very fast  and get greasy by lap 2 or 3, yet other cars take longer to get up to  speed. There were some quick TT1 and TT4 cars that were quicker at the  end of the session, but rolling roadblocks early on. So I wasn't getting  a clear track until lap 3 or 4, and by then the A7s were boiling and  the oil temps spiking. Frustrating. This not being my home region it  took a little time to get to know the local TT competitors and I was  hoping that on Sunday I might be able to grid swap with some folks to get a clear lap 1 or 2.

I  was really abusing the A7s by running them for 4 or 5 hot laps in a  session, and usually by then the high oil temp issue would crop up and  the car would go into limp mode, cutting off the top 2000 rpm of engine  revs. Some of my best laps Saturday were while running in limp mode.


Session  4 was better - I had parked at the very BACK of the grid, planning  to hold back a LOT on the out lap and try to get ONE lap clear of  traffic early on in the session. I sat back there until a few guys came  and asked what was up, then they moved me to like the front of the grid,  and WHAMO! I was able to get a quick first lap, dropped 1.3  seconds, and jumped into 2nd in class with a 1:52.190 best. I was back 5  tenths for the day (final Saturday TT3 results shown above), but 5  tenths is not much - maybe I can find that on Sunday, getting clear  track in an early session?

Sunday - TT Race 2

Now  that I was dialed in a little better to this setup and track, I planned  on getting my best lap in the first session Sunday. The temperatures  almost always worked out to be more favorable on the first session, and  this day was no different.


I gridded better and built a bit of a gap, so I had not only a clear  first lap but a clear second lap as well. Bruce as behind me but I was  enough ahead that I didn't impede him, and popped off a 1:52.177 lap 1, which was only 2 hundredths quicker than my Saturday best. I kept going and slowed down to a 1:52.544 on lap 2, but still kept at it for a hot lap 3. The rear tires were sliding like mad and I knew I had overheated the rears. Oil temps had spiked and the tires were toast. I pulled off line after Start/Finish, backed off and let Bruce go by me. That sneaky M3 driver had put some A7s on without me noticing, ran his personal best of a 1:51.873, and he jumped ahead of me! Dumas put down his best in this session at a 1:51.760 staying in 1st once again.


And that's how the day ended, with no TT3 competitor going quicker in later  sessions. I came in after that first session and noticed a patch of cords on peeking out of the left front tire, so I was done for the day.


The video
shows a couple of laps in this first Sunday TT session, where I almost  exactly matched my time from Saturday. Losing sucks, and a 3 tenth  spread from 1st to 3rd made it harder. I had seen a 1:51.5 predicted time, so the car had more in it, I jut couldn't find it. My stupid mistake of gentle out laps hurt the braking performance on lap 1, which I didn't figure out until it was too late. With cords on the LF tire  there was not a good way to find that time in a later session.


So the $2000 set of Hoosier A7s were done in less than 2 weekends. Fudge.  It has a lot to do with the weight of this car (3900 with driver and  fuel), maybe little to do with the power potential of this engine, some of it is my driving style, but mostly the fact that this 315mm tire is still relatively narrow for the massive weight of this car. I didn't help things by taking more than my normal 1-2 hot laps on most of the 12 heat cycles I put into these A7s, which hurts their lifespan.

The weekend ran well, and NOLA region does a great job even when it is a  merged event with Texas region, which triples their attendance. Sure  there were a number of delays, and we ran about 1 hour behind schedule all weekend. But its the Big Easy, and you just roll with it. The suspension and spacer changes we made since COTA helped - the tires were tucked under the fenders and no longer rubbing, the suspension wasn't bottoming, and the brakes worked very well (once I put a little heat  into the pads). I have since learned to not let the brakes stay ice cold  for my first hot lap, so my out lap procedure now puts a little heat into the PB13 front pads, and they work perfectly on the first lap now.


I ran that dismal 1:56.867 best lap here with Optima back in April, with the brake hydraulic mismatch issue, on 200TW street tires. Finding 5.7 seconds  from that event to now was partially from the differences in tires, but the massive improvement in braking was most of it.

All of the fast cars in TT1/2/3/4 were gutted race cars with full aero, but  here we were in a street car with full interior, a stock engine, and  out of the box R&T coilovers. Maybe losing by 3 tenths on Sunday shouldn't sting, but it still did. It was beyond time to address this oil temp  issue, and I needed to think about cutting this car (to add more tire) and putting on some real aero, or the performance is always going to  suffer in TT3.


If  you have been following this build thread you know we have posted many times about "high oil temps" on this 2018 model. Other 2018-19 GT track rats have seen the same thing. After 1-3 laps of HARD track driving the oil temp gauge (a digital "analog sweep" readout, but with no numbers associated to it!) spikes into the red, then the computer implements a limp mode that chops off revs to 6000 rpm max, and if you keep pushing it, it drops to 5000 rpm.  By that point I just give up and come in to let everything cool down.

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What's going on here? Why is this effecting 2018-19 models and not 2015-17  GTs? We have some theories. Contrary to popular belief, we don't just  service Mustangs, and not all of our customers are 100$ track rats - so we have only worked on a handful of 2018+ Mustang models. Our car is what we have the most first hand track experience and this oil temp issue with, but others have mentioned similar issues on these cars  online.

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Question: Don't these cars have a factory oil cooler? Answer: Yes they do - see above right.  This little heat exchanger "brick" has radiator coolant that passes through it to both PRE-HEAT and hopefully "cool down" the engine oil once it has reach operating temperature. The radiator on the base model GTs are also much smaller than the PP or Shelby cars, as shown above left) and  we think that the pre-heating (for engine efficiency / fuel mileage)  works a little too well.


The  2018 GT also got this electronically controlled grill louver system -  which can BLOCK OFF ANY AND ALL AIRFLOW to the radiator. This was  originally designed for the 2015 Ecoboost cars but Ford put it on the  non-PP 2018 GTs as well (see this article).  "active grille shutters (on all Mustangs not equipped with the optional  Performance Pack) to reduce drag at higher speeds" That isn't helping things if it is programmed a little aggressively.


We  knew that Mishimoto made a complete oil cooler kit for the 2015-17 GT  but were told that it needed some changes to fit the 2018-19 cars. We  aren't going to go into every detail on this oil cooler install, as I'm  waiting for Mishimoto to produce the 2018-19 GT kit. Just the  highlights.

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The front bumper cover has to come off, as do the coolant lines and main  radiator hose shown above. Then an oil filter sandwich plate goes in  place of the little cooling brick shown before.

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This  oil filter sandwich plate is a very well made part and has a thermostatic bypass, so cold oil doesn't pass through the Mishimoto heat exchanger. It also has two 1/8" NPT plugs - one of which we installed with an oil temp sensor (more on that later). The "Active grill shutter" system is in the way of where the heat exchanger goes, so it was removed.

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The sandwich plate plate is installed at the oil filter location (after removing the Ford brick) and the included -10 AN braided lines go from  there to the external cooler. The oil filter then goes back below the plate, in the same spot as the OEM.


The  heat exchanger is nicely sized and fits right behind the factory upper  grill opening, with a well made bracket that attaches to the carbon  composite radiator support structure above. The lines connect to the  single pass cooler at opposite ends, as shown.

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The  install is pretty straight forward, other than clocking the sandwich  plate and routing the lines. It gets a little tight around the giant  Whiteline swaybar, but there's a 1/2" of room to the hose ends. We only added a little bracket with a Vibrant dual hose separator attached to keep the braided lines from sawing into any nearby plastics, but that might be overkill.

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Brad and Evan wrapped up the oil cooler install and we moved on to the new temp gauges...


Rumor has it that the factory "oil temp" gauge readings are fake - they are  inferred numbers based on other inputs and readings. I also wanted "real  gauges" that I could see without having to scroll through menus while  on track. Ideally these could be data logged, but with a rear mounted  camera (and me calling out temps while driving to the mic) I could  capture this data with discrete, analog type gauges.


I purchased these three 2-1/6" "GlowShift" gauges above, which are ranged and marked for engine Oil temp (100-300F), Trans fluid temp (80-260F) and Diff  fluid temp (100-250F) uses. Electric steeper gauges, work pretty well. These are all three trouble spots on the S550 chassis, especially trans and diff (and for 2018-19, oil temp). It  would have been better to install real gauges for engine oil temp sooner, but our testing and work schedule doesn't always allow for this. Instead we planned to install oil temp, diff temp, and trans temp gauges during the Mishimoto oil cooler install (since the sandwich plate had  the oil temp sensor port).

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We popped the front dash cover off then the center top panel of the dash  was removed. We plan to mount a 2012-13 Boss 302 Ford Racing triple  gauge pod to this panel, which can be replaced if we ever want to un-do all of these mods.

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There were many aftermarket gauge pods to choose from out there but none of them looks half as good as this Ford Racing unit, made for mounting three 2-1/16" gauges.

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Once the gauge pod was mounted to the upper dash panel the GlowShift electric stepper motor 270 sweep gauges were installed and wired in. I'm not  going to bore you with the steps for wiring but it takes a number of hours to do this correctly - where it is tired into the light circuit, with fuses, and soldering and heat shrinking everything. Brad also added weatherpack  connectors near each sensor, so that things like the trans and diff could be removed by just unplugging the sensor circuit.

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The MT82-D4 six speed manual trans was easy tap get a sensor into. We researched, ordered, then replaced the M16 threaded lower drain plug on the bottom with this special adapter we found, which has a 1/8" NPT female opening in the middle. This meant we needed to do a trans fluid change, the 2nd in 1800 miles of use, but its never a bad idea.

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The diff sensor install was a bit last minute, and I did this one myself. I had  ordered what I thought was the right adapter, in stainless steel, with overnight shipping. But what showed up five days later (!?) was wrong. Some evening searching in the Home Depot plumbing aisle got me what I needed: a 1/2" MIP to 1/8" FIP adapter. This replaced the stock 1/6" NPT lower drain plug.

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One thing I noted when adding this sensor: when I drained out the diff (which we had changed early on to MOTUL synthetics) it was about 1/3rd of the fluid missing... gone. It has been boiling off due to high temps, we  suspect. And there was a LOT of material on the magnetic drain plug. This was likely material from the clutch packs on this base model car's clutch style differential (its worn smooth out). The Performance Pack  and Shelby cars all get a Torsen.


These gauges really do work great, especially considering they are under $70 each. The install was a total pain but in the long run it should be worth it. I am making sure I take a picture of the gauges right after I come in (it  takes several minutes for them to cool down from their peak numbers) from each session, hopefully getting the AiM Solo readout to know which session (lap times) they correspond to. Again, once I get the rear mounted vidcam in place this shouldn't be necessary. Already seen some great data from these 3 gauges.


This  was a member day at  MSR Cresson where they were running the 1.7 CCW  and a bunch of buddies were going. I had finished the gauge install the  night before and was going to load up onto a trailer in the morning. Due  to some things out of control, my enclosed trailer and the open trailer  I normally use as back-up were both out of commission.

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I borrowed a trailer the night before, picking it up late and in the  dark. In the light of morning we noticed it was about 4" too narrow to  clear the track width of this car - it would be inside the trailer  fenders. So we went to a nearby trailer rental place and rented their so-called "car hauler", which took a lot of ramps and wood to get the car up onto the deck (of this tractor/utility trailer). The fenders were so tall I  had to crawl out the open window. Good thing we didn't buy a Camaro - that would be impossible!

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We made it to MSR rather later than we had planned, but the weather was  overcast and cool so the "early session" wasn't the only fast session. The weather was so nice in fact that the track was rather crowded with members, and that turned into a challenge for getting clan laps.

Picture and video gallery:

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