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CBraden

CBraden

Member Since 19 Aug 2016
Offline Last Active Nov 12 2017 09:32 PM

#99247 WTB: Race capture pro Mk2 or Mk3

Posted by CBraden on 12 November 2017 - 09:28 PM

I can confirm that was sold. :smile:




#94080 1972 Opel GT Track Package

Posted by CBraden on 09 June 2017 - 01:39 PM

OK, clearly I don't know how to post video here... is there a tutorial somewhere?

 

<iframe width="560" height="315" src="https://www.youtube....ed/loo42rv1M00"frameborder="0" allowfullscreen></iframe>




#94079 1972 Opel GT Track Package

Posted by CBraden on 09 June 2017 - 01:38 PM

Understand and definitely not a critique, just an observation based on my own experience as you note.  The good thing is that setup really likes the go pedal in the fast sweepers. Getting on the gas is almost always the solution to instability.   :wink:

 

 

BTW - and it will always feel like it wants to kill you, that's what keeps it exciting.  :laugh:

 

Agreed, the car likes to be driven on the gas. The Opel has coilovers instead of the spring on the trailing arm, and tuning with bump stops helped enormously with the rear behavior - with the OE (OK, OE for a BMW 540 where the shocks came from) bump stops, once it hit the stop it was counter steering time _right_now_ but it is pretty easy to drive now. As you can hear in video below, you can get in and out of the gas in corners without it spinning.

 

[/media]

 

Personally, I like a challenge and it was definitely more exciting to drive before the taming of the oversteer, but since it exists for endurance racing and there are other drivers (and drivers can get tired toward the end of a long stint), it gets tuned to be as easy to drive as possible.




#94066 1972 Opel GT Track Package

Posted by CBraden on 09 June 2017 - 11:24 AM

This is a really cool and bespoke looking build -- they were having cooling issues at COTA last summer.  Hopefully those teething issues have been resolved.

 

Mike

 

Thanks lonestarrpm - yeah, major cooling issues @ COTA - ducting work to radiator and an XL oil cooler solved those based on TWS engine/oil temps last month. Now if we could just make the inside of the car cooler...




#94065 1972 Opel GT Track Package

Posted by CBraden on 09 June 2017 - 11:20 AM

Matt and Hornet, thanks for the kind words.

 

Bob, swapping suspension involves tons of criteria, and Z3 was what checked the most boxes (though most certainly not perfect). Also not sure if you are being ironic since your avatar has the same rear suspension  :smile:. The internet says there are ways to make it work without it trying to kill you... hopefully we will figure them out (j/k it does OK).

 

Jared - since racecar = weight is primary objective, headlights are gone (actually in the attic) due to weight off the nose, I think they were almost 30 lbs of parts altogether, plus the car is so small that space is actually used for other stuff now. 




#94028 1972 Opel GT Track Package

Posted by CBraden on 08 June 2017 - 08:45 PM

There is no reasonable explanation for this build.

 

crop2hresDSC_1677_3.jpg

 

1972 Opel GT shell (door hinges only remaining moving parts from Opel)
Chevy Truck V8 (4.8L - stock cam and internals)
Ford Mustang T5 (with Chevy S10 tailshaft)
BMW 325i front suspension (parts from e30, e36 and e46)
BMW Z3 rear suspension and diff 
BMW 330i brakes (e46)
Corvette driveshaft (C4)
 
Fourth race for the car was WRL @ TWS May 2017 - shows real potential, but still a work in progress .



#90125 How long are you getting out of a set of brake pads?

Posted by CBraden on 29 March 2017 - 02:42 PM

Replying to add another data point in case people search in future.

 

For non-street pads, after much experimentation - if you can run low amounts of power/vacuum assist or manual brakes, I can't recommend Raybestos race pads highly enough. ST43 last so long, I honestly don't have a wear projection on them, but it would be 70 to 100 race hours I am guessing. This is on two different cars 2425 weight, 150 hp, SN95 Cobra front brakes, and similar wear on a 2550 lb car, 255hp, e46 330i front brakes. They squeal more than any other pad I have heard, but for a race car, who cares. They don't seem to wear rotors, and the braking power is excellent. Never had fade (run vents in both cars), but we run 200 TW tires (255/40/17).

 

I will caveat: If you have highly boosted brakes, stay away, they can be too grabby to modulate in that application.




#87253 Maxxis VR-1 vs. Dunlop Direzza ZII Star Spec for HPDE tire

Posted by CBraden on 07 February 2017 - 11:28 AM

Just adding to this topic in case anyone searches in the future. I have used the Z2* and the VR-1 in the same size on the same car exclusively on track at speed, and I preferred the Z2* (next set of tires will be Z2*, unless Z3* or RS-4 shows more promise).

 

If the Z2* was sold out, I would be OK running the VR-1 again, but I felt it had less grip (though both are very predictable and easy to drive). Honestly, if I couldn't get the Dunlop, I might try another tire just because I like testing things - the Federal RS-RR looks interesting.

 

The Z2* seems to handle heat better

The VR-1 seemed to take a much longer time to scrub in to the point where it was predictably sticky (read: 2+ hours in Texas heat for VR-1 vs a few laps for Z2*)

Both these tires wear well, but I think the Z2* wears slower than the VR-1 @ race pace - I would guess I am getting a few more hours for the Z2* for a set

I wanted to like the Maxxis better as they are cheaper, and can get them direct, but I am back to Dunlops.

 

Braking seems equal between the two, the differences are mid corner to track out where the Dunlop seems more tolerant of heat and slight abuse.

 

If I had never driven the Dunlop, I would be driving the Maxxis again, they are better than the 615k/Kumho XS/NT05 stuff for my uses.