Lime Rock Park Proving Grounds Autox 6-1-24

I have not done one of these for quite some time, wow. I had to look back at some previous posts on how I usually formatted these. Some background: This is the 3rd time I’m attending this event, but in a way just my 2nd. After doing this event for the first time last year, and getting FTD & invited to the shootout, I had a transmission failure during the shootout event. Somehow, downshifting from 3rd to 2nd, the transmission jammed, getting stuck in 3rd. So, off to TRE – the trans had needed a rebuild for a while, the synchros were going and 2nd gear had been popping out with ease – a massive issue for autocross.

The transmission rebuild was fine – surprisingly, the gears were in great condition for ~35k miles of abuse. There had been some signs of overheating, but nothing too crazy. The synchros were absolutely toast, and one of the synchro keys was on the magnet. The rebuild went quick, went back in the car fine, but 2nd, and now 1st gear started popping out. I had hoped for a simple fix – I installed shifter cable bushings and shifter base bushings – surprisingly two easy modifications that I had never bothered. The lower shifter cable bushing was a pain to get to, but eventually was able to knock out all the bits. Shifting quality improved, but no change to the gear popping out issue. I sent it back to TRE, and it turned out it was a simple collar that was not in place properly – a “violent” shift from 2nd to 1st letting the clutch out actually forced the collar back in place, and the popping-out-of-gear issue went away completely, leaving me with a fresh trans that felt amazing to shift.

Fast forward to this event, and while everything went fine, I jumped one of the curbs on one of my warmup runs, while staying WOT. I didn’t notice any issue at the time, but when I did my final timed runs, the car felt really odd. First thing I noticed was that the car felt like it didn’t want to turn. I assumed I had actually overcooled the tires, which I had been spraying with water between runs. The car just seemed to lack grip/tires felt off, and the front tires moaned every time I turned the wheel. I also encountered ice mode on braking, where the car almost flat out refused to turn. I experienced it frequently in the Mini, maybe once in my entire ownership of the Evo. I ran a 44.8 on my timed run, a full half second slower than my warmup runs. I chalked it up to having overcooled the tires, and packed up and left the event. On the drive home, massive whining in higher speeds, and on decels to 0. Only in gear. Either the transfer case, front diff, or both seem to have failed, which matches my experience of the car not wanting to turn, especially the front wheels. We haven’t fully gotten to the bottom of it yet, but I’ve gone ahead and purchased new front and rear diffs, in an effort to change the setup to something more reliable.

Hoping the car will be fixed and back out there, for at least one more event before the shootout.

Set Up (Evo):

  • Ohlins DFV (Custom valved); Shocks 6/8
  • OEM FSB 4/5; WL 26mm RSB: Medium
  • RE-ACD: Gravel; ATS 1-way CH Front Differential; ATS 1.5-way CH Rear Differential
  • Camber at -4.0 0 toe, -2.5 rear, 0 toe-in
  • Brakes F: AP Racing 8350, Ferodo DS2500s, Brakes R: Girodisc 2-pc & ST43s
  • CE28N 17×9.5; 255/35-18 Bridgestone RE71RS
  • 36psi

Notes (Evo):

  • Tires have probably 20-30 equivalent runs on them, they do ok with heat

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