I'm running my first autocross in over 20 years this Sunday at the AutoClub Speedway in CA. Stock E92 335i 6MT with ZSP and 19" ZCP style wheels. Michelin Pilot Sport 235/35 PS2 front, 265/30 PSS rear.
I drive my car on Mulholland Drive every morning. What I've noticed so far: The 335i has a bit more body roll than my M Sport II E39. This is due to the small (13mm) rear sway bar. The staggered tire sizes don't help either. But I haven't been troubled by understeer -unless- I get heavy into the throttle too early in the turn.
The simple driving adaptation to understeer is: Turn in later into the turn with more trail braking. When you're doing it right it will feel like the car is "pivoting" slightly under you. Don't dip into the throttle until you can at least see the apex, even better have one of your front tires nearly on top of the apex.
Also, the Steptronic probably doesn't help because it reduces your engine braking to the rear wheels (torque converter). More engine braking helps reduce understeer because it makes the rear tires work harder. Are you downshifting going into turns?
I would be interested in hearing what tire pressures you guys have run with stock ZSP suspension. Obviously less pressure in the back with stock ZSP would work, but how much bias?
Also, what do you guys think of running DTC vs. traction control full off? I was thinking of doing my practice run with DTC and seeing how that responds. If it intervenes too much I can turn it full off.
Last edited by NoTempoLimitN54; 09-28-2012 at 11:14 AM.