C5 autocross set-up question
#1
Safety Car
Thread Starter
C5 autocross set-up question
First, please don't tell me to ditch the F45 and get coil-overs, etc. 2nd I can't afford any major mods right now.
What I have: regular non-Z06 2001 coupe, 6MN, F45, minor cat-back, CAI mods, lowered on stock bolts, C6 Z51 front sway bar w/stock ends. Ran the first time a couple of weeks ago with Nitto NT-01's after running Kumho MXs the last 2-3 years. Love the Nittos. Now the rearend is not oversteering with the added stick but now getting more understeer on exit, or am I overcooking the corners since I'm sticking more on entry? I have the rear C6 Z51 rear bar sitting in the garage. Should I install that bar? Could that reduce the push by snugging down the rear a little more? This is basically a free mod since I'll do the install and I already have the bar.
So my question is to install the rear C6Z51 bar, or not, or give myself more time riunning events with the Nittos?
Thanks for you in advance for your educated guesses, opinions, advice
What I have: regular non-Z06 2001 coupe, 6MN, F45, minor cat-back, CAI mods, lowered on stock bolts, C6 Z51 front sway bar w/stock ends. Ran the first time a couple of weeks ago with Nitto NT-01's after running Kumho MXs the last 2-3 years. Love the Nittos. Now the rearend is not oversteering with the added stick but now getting more understeer on exit, or am I overcooking the corners since I'm sticking more on entry? I have the rear C6 Z51 rear bar sitting in the garage. Should I install that bar? Could that reduce the push by snugging down the rear a little more? This is basically a free mod since I'll do the install and I already have the bar.
So my question is to install the rear C6Z51 bar, or not, or give myself more time riunning events with the Nittos?
Thanks for you in advance for your educated guesses, opinions, advice
#3
Instructor
If your lowered all the way on stock bolts I'd raise it up some, about 1/2inch helped me out.
I went from C5 Z51 bars to C6 Z06 bars on both ends and the rear was to tight for myself and I went back to the Z51 bar on the rear. But if you already got the bar give it a try.
A cheap shock upgrade is a set of C6 Z06's if you want to get way from the F45.
I went from C5 Z51 bars to C6 Z06 bars on both ends and the rear was to tight for myself and I went back to the Z51 bar on the rear. But if you already got the bar give it a try.
A cheap shock upgrade is a set of C6 Z06's if you want to get way from the F45.
#5
Safety Car
If the rear end is sticking and the car is pushing then you need to dial out some front bar or increase the rear bar. I'd put on the bigger rear bar as I'd want a tail happy car for auto-x. Oh... and ditch the F45 stuff... probably worn out by now anyway.
#6
Melting Slicks
Member Since: Jun 2002
Location: Charleston South Carolina
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This first. And then you could reduce your rear toe-in if you run a lot of rear toe-in. And you might want to raise the rear of the car to add some rake if you've lowered it so much you've taken the rake out. In autox you actually want a soft rear bar to get the power down on exit.
#7
Understeer
What air pressure do you have in your tires?
Use the chalk method on the outer tire tread and tire sidewall on three places around the diameter. Make a run. If the chalk is completetly gone on the tread, you are utilizing the full tread. If there is chalk remaining on the outer tread, lower the air pressure a pound or two and run again.
If the chalk is gone on all the tread and some from the sidewall of the tire, the tire is rolling over. Add air pressure and run again.
Doing this will optimize the tire tread.
If this does not resolve you understeering, persue alignment, and bar adjustments.
Roger T : )
Use the chalk method on the outer tire tread and tire sidewall on three places around the diameter. Make a run. If the chalk is completetly gone on the tread, you are utilizing the full tread. If there is chalk remaining on the outer tread, lower the air pressure a pound or two and run again.
If the chalk is gone on all the tread and some from the sidewall of the tire, the tire is rolling over. Add air pressure and run again.
Doing this will optimize the tire tread.
If this does not resolve you understeering, persue alignment, and bar adjustments.
Roger T : )