Contour Enthusiasts Group Archives Forums General Autocross and Open Track 51 lbs air in front is too much!!

Autocrossed today and tried Chris Ludwig's (rrxp689) higher air pressures on my front KDWs. IMHO that's a big no go. I always go fast on my first run and am usually pretty consistent in my runs without big improvements at any given setup:

1st run: 66.595 clean, smooth run
2nd run: 67.139 got way sideways once
3rd run: 68.205 got tail-wagging sideways
4th run: 66.615 went slower and smoother again. Note similarity to 1st run time.
Decided that the car felt funny compared to running it previously at just 45 pounds at previous events. Lowered front pressure from 51 lbs to 46 lbs. Kept rear at 45 lbs.

Result: 5th run: 65.677

A full second faster on a run just as smooth as my 4th run at higher pressures.

We had high quality out of region visitors again so I PAXed my time against theirs. Heath McMillan brought his CSP Honda CRX that he won the 99 National CSP Championship in. He ran a 59.787 raw time. Renee Hines who is now running the same car at Atlanta and beating all the guys in CSP ran a little more than a second slower at 61.035. PAXing their times yielded:

Heath: 50.221
Me STS: 50.359
Renee: 51.269
Me G Stock: 52.147

I always run G Stock but on street tires so I threw in the STS for comparison.

Conclusion: Trust me when I tell you that my first run is often my fastest or close to my fastest. My times are nearly always very close together. So a full second improvement leads me to believe that 46 lbs in front is better than 51 lbs. With that pressure your contact patch is just too small. It is great for tire wear, though. I may start running earlier runs at 50 and then lower to 45 for the final run to save tires!! This was also on concrete where more rollover would normally occur, so if 50 was going to be good anywhere it would be on concrete.