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XLR8

New build - RX8 LFX swap

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Last year i had a friend start a new WRL/AER build using an RX8 with an LFX swap kit from https://www.keislerautomation.com/ 

The car is a blast to drive, offers lots of room inside for a cage, is well balanced and cheap to build/maintain.  In December i pulled the trigger on my own build for weekend/TT car. I bought  really low mileage blue RX from a seller in Denver. Andrew Keisler who builds the swap is doing the work for me outside of Denver. The cars are cheap and plentiful but the real bonus is the drivetrain.  It's using the GM LFX v6 along with the camaro trans and diff. You pick the gear ratio or diff but all in my drivetrain was $2200 shipped. The ECUs all talk to one another and all the gauges will work.

I'm short on time right now but here are a few photos.  I'll have the car at some NASA events and at ECR members this year if anyone wants to see it.

 

 

 

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3 hours ago, jared said:

Following.

I've been waiting for the Rocketeer Swap guys to get the NC done and move to the RX8. I didn't realize an LFX swap was so "cheap".

Not familiar with them but anyone swapping is good with me.  I'm guessing you don't consider this cheap but for a fully integrated swap that can be done by someone themselves in 50 hours i'd say this is about as easy as you can get.  

17 hours ago, robertcope said:

Ooooh. These are so hot.

Indeed!

Engine is in now. Also photos of oil cooler and engine vent mockup.

 

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The exahust manifold integrated into the block saves alot of room. I've seen toyota do this with their turbo cars, but I haven't seen it yet on a NA car. It also has 3 too many cams ?

 

Looks like it'll be a fun car. There use to be a TDE instructor with a similar swap in a RX8. It was pretty fast. 

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And a few more about the brakes.

Wilwood Superlite 4 piston calipers
Custom front stainless steel brake lines
CNC machined adapter brackets and hardware.

Why a caliper upgrade? Why not a complete big brake kit?

Economically priced @ $600.00 vs. typical "BBKs" $1800+
The most inexpensive Rx8 unsprung weight reduction on the market.

OEM floating caliper assembly weight- 11 lbs
Superlite caliper + adapter bracket weight- 4.95 lbs
Over 12 lbs of total unsprung weight reduction

Upgrading to a larger 2 piece rotor will show minor improvements compared to the caliper upgrade. 2 piece rotors are approximately 2-3 lbs lighter than OEM and cost $700.00+ compared to $20.00 OEM centric rotors. When it comes time to replace the disc on the 2 piece rotor, the cost will still be upwards of $400. That money is better spent elsewhere for most applications.

The caliper upgrade kit is designed around the Front Mazda Rx8 SPORT rotor. At 12.7" diameter, the rotor is sized sufficiently for competition use.

Superlite calipers utilize a quick change brake pad design for track-side modularity.

Superlite calipers house THICK brake pads at .63" for drastically extended pad life.

Decreased brake fluid temperatures due to the Superlite calipers large aluminum composition.

Fixed caliper design eliminates additional moving parts and potential failures found with floating calipers under extreme temperatures.

9% increased front braking force. The added front braking force is optimal when utilizing aggressive 200tw, R-comp, and slicks which shift increased mass to the front axle.

The caliper adapter brackets were engineered and FEA simulated to withstand infinite braking cycle loads of 1650 foot pounds of torque. In other words, they will never fail.

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On 1/17/2020 at 12:18 PM, XLR8 said:

And a few more about the brakes.

Wilwood Superlite 4 piston calipers
Custom front stainless steel brake lines
CNC machined adapter brackets and hardware.

 

The LFX is the a great swap, I am doing a more standard 2.5 L swap and would like to do an LFX in the future.

Where did you get the caliper brackets and hardware? I have the standard BBK on my NC and the pads are tiny in comparison so I am looking for a better solution.

And which specific caliper did you get? I am looking at the 120-11128

 

 

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Are you confident this caliper change is an improvement?  It looks like the pad sweeps a good bit less rotor surface than stock, and the stock brakes are really quite good.   For a NC or RX-8, the big RX8 brakes are difficult to beat under a 17" wheel.  

 

Andris

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20 hours ago, skillman11 said:

The LFX is the a great swap, I am doing a more standard 2.5 L swap and would like to do an LFX in the future.

Where did you get the caliper brackets and hardware? I have the standard BBK on my NC and the pads are tiny in comparison so I am looking for a better solution.

And which specific caliper did you get? I am looking at the 120-11128

 

 

The 2.5 is a lot of fun and you'll enjoy.  Calipers and bracket are coming from Keisler Automation, he designed and machined the bracket and did the engineering.  I'm merely his guinea pig.  See his Facebook site and there's a post about this, you can ask him there. 

9 hours ago, Andris said:

Are you confident this caliper change is an improvement?  It looks like the pad sweeps a good bit less rotor surface than stock, and the stock brakes are really quite good.   For a NC or RX-8, the big RX8 brakes are difficult to beat under a 17" wheel.  

 

Andris

Yeah i noticed that too. I didn't design or engineer the solution and am merely a test subject....well I'm the first car at least.  We'll be testing them this spring but the math says these will provide more stopping force.  I agree that the stock brakes are good and if this doesn't work i'm not out much money.  

8 hours ago, skillman11 said:

Are those the calipers that come with the sport suspension like these from RockAuto? 

 

No sir, these are Wilwood. I'd stick with the stock calipers unless these work as we hope they do.

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Latest update:

Just sent an order into Penske for some custom 7500DA shocks. Keisler is speccing 3 sets uniquely made for the RX. He will be machining all shock ends to fit them perfectly to the chassis.  The RX has an unusual rear top shock mount so these will be inverted and provide around 7" of travel.  Most off the shelf solutions provide 3" give or take.

The math says these will be a slam dunk...we'll see.  

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Car shipped last week and is at a friend's house this week getting it's rear cage work done. Penskes should be here in March and hopefully it's ready for ECR NASA but it's gonna be close.  Last tidbit to get sorted is fuel pump.  It's got the typical saddle tank, one pump deal so need to figure out how to deal with the low fuel level issue.  For the Spec e46 Bimmerworld made a kit that you installed a transfer pump on one side, removed the inside tubing and connected that pump to the main and wired it on. One hour of work and allowed me to get down to under 1/2 Gal. Anyone think i could use the same thing here?  Link below

https://www.bimmerworld.com/SpecE46/E46-Fuel-Starvation-Kit.html

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It's been long time since i submitted an update but not much was done until the last few weeks.  I got the car back to Dallas in March and pulled the sunroof and installed a proper steering wheel.  I also took it out to Darin @ MER for tune.  We tuned for 93 and came away with some very nice curves....285 whp from 6250 to redline at 7250.  Torque came in at 246 from 4500 to 5500.  

The car was really damn loud, apparently running with no cats and only a few resonators will do that but i couldn't take it.  I added a sideways Magnaflow with a turndown exit behind the drivers rear tire (more on that soon). Still too loud.  I then added another Magnaflow resonator before the diff and after the Y pipe.  It's perfect (almost) now and can be heard on the track but is fine around town. It's tough to make a NA V6 sound good that's for sure.

Installed some 17x10 RPF 01s and 275 R888Rs.

I'm still waiting on the coilovers from Andrew and Penske.  The machined parts are coming from Germany and have taken much more time than normal.

On order is a new from bumper which i'll match to a splitter and 9LR rear wing with custom gooseneck uprights.  I won't do all that until the Fall though when i'm prepping for the 2021 TT season. I need to sort out safety equipment, cage seats and whatnot...not sure what i'm doing in that regard yet.

Lastly, i took it out to ECR yesterday for a member day.  Drivetrain performed flawlessly and running on the original struts and springs was awful as you can imagine.  I had a few tingling moments when i pushed it a bit too hard. It was my first time there since the rear section opened and I have a ton to learn. Car is still in 4x4 mode so putting 2 off, which happened a few times, wasn't a big deal.  Car will sit about 3" lower soon but won't be so damn scary.  Now to that exhaust....i had a feeling this would happen but that turndown melted the lower corner of the bumper and i ended up having to rip it off. I'm going to trim the entire lower section of the rear away soon since it's just a damn parachute.

Still happy with my choice of build but have a long way to go.

 

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On 1/20/2020 at 11:18 AM, XLR8 said:

Here's an interesting read, the owner of the shop who makes the swap kit put this little document together.  Full of great details.

LFX+Car+Comparison+Brochure.pdf 14.63 MB · 12 downloads

Wow - really cool to see those torsional rigidity numbers. I knew the RX8 was a solid chassis but seeing the comparison to other popular track vehicles is eye-opening. I'm guessing the NC Miata doesn't have anywhere near the same rigidity even though the chassis closely related to the RX8 (given the whole no roof thing and all).

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30 minutes ago, vchengap said:

Wow - really cool to see those torsional rigidity numbers. I knew the RX8 was a solid chassis but seeing the comparison to other popular track vehicles is eye-opening. I'm guessing the NC Miata doesn't have anywhere near the same rigidity even though the chassis closely related to the RX8 (given the whole no roof thing and all).

Yeah don't think the NC is even close, for obvious reasons as stated.  You can tell just when closing the doors how rigid the car is, it feels like a tank.  I'm pretty happy so far but need more budget to get it completely sorted, but as a project guy i need this car to carry me over for awhile. 

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