Well, it's been two track days since my last post, one at Heartland Park Topeka and one here at Gateway International Raceway in St. Louis.
When last I posted, I was still fighting some pretty good understeer, so I made the following changes:
- Lowered front ride height 1/4"
- Using the washer trick on the lower strut bolts, managed to increase the camber up front from -2.2 to -3.1
- The new rear bar did NOT go on, as it didn't fit.
- Replaced destroyed 3.73 Clutch-pack LSD with a 3.46 Torsen unit from an 01 3.0 Z3 (40k miles).
Heartland Park (10/2/2010) results (sorry, no video GoPro case broke). - Man, a Torsen diff is a very very different beast than the clutch pack. The tail just sticks and sticks and sticks under throttle, until it doesn't and then it goes quick! Not the gradual break-away of the clutch pack, but it seems to stick better. Definitely takes some getting used to!
- Even with staggered tires (had to run my streets as I corded my slicks), the new setup was rather twitchy. Following dahamler's advice, I disconnected the rear swaybar. It seemed to settle the car a bit, but I think I'm going to put it back on at Putnam next Friday to see if some of my other changes have dialed that out.
- Worked tire pressures to help improve balance, but sadly it wasn't good data for me as the slicks are a whole different game.
Final result: The car was getting to be pretty darn quick even on its streets, starting to catch some M3s and other decent hardware even though they were running R-Compounds. Pretty good result given that this was the Instructors/Advanced only day.
Gateway International Raceway (10/13/2010) results - On slicks this time, working on tire pressures. Everything else was left alone.
- Car did a pretty good job, driver was having a hard time hooking up. It was faster than EVERYTHING in the Advanced/Intermediate group, even lapping a couple of cars twice. Apparently not many of the cars were heavily prepped. On the last session I was running 1:14s, but the car was definitely capable of running 1:12s. Needed a couple more sessions to get back in the GIR groove as it had been 2+ years since I ran at Gateway. Sadly, I won't get another chance as it's very likely that they're closing the track this year.
Still, it was a fun day, and it's nice to be getting all the point bys and not having to give any. It's not a competitive event, and it's all about learning, you shouldn't care what the other guys are doing, but it's nice to see you've done a decent job with car prep.
Video comp from Gateway showing every pass of the day:
Changes since Gateway: Added a 1.25" trailer hitch to pull a tire trailer (or mount bike rack).
Will have to fix a newly developed power steering fluid leak.
Next track day: 10/29 at Putnam Park Changes to try:
- Re-connect rear sway and evaluate.
- Work with tire pressures and wear, hopefully collect some tire temp data.
- MAYBE collect some actual telemetry using a proper data-logger.
Will keep everyone posted as I have time.
Thanks for the support everyone!