xray_racer

Just wondering what people recommend as far as tire pressure goes for autocross racing. Let's say on a sunny day about 90 deg F if that makes a big difference.

Judder

On the stock continentals I run 38 front and 36 rear.

lewis_trash

Dude you may save gas with that amount of pressure, but your tires are definatly gonna wear in the middle. I run 34 in front tires, and 30 back (and the sidewall barely touches the ground)

peachpuff

Add 10psi in the front and a bit less in the back for autocross.

metroplex

+1

I run 30 psi all around and the shoulder corners are not touching the ground. The stock tires are too stiff (XL) for the light chassis, or the tires are overinflated at 30 psi. I think it is a combination of both since the tires are rated for 186 MPH (Y) and the car can actually drive 150-160 MPH.

Judder

The question was for autocross, I do not run that much in my daily driving.

ogc

For autocross on stock tires I ran 35 front and 38 rear.

30 psi is to low for hard cornering on stock tires in my opinion.

Maybe as a cold pressure that could work, but hot you want to be at least 35 psi, and I havent experimented over 38 or 39.

Terminator2

It seems like any more then 35 psi in the front causes the car to ride mostly on the center of the tread so less contact patch and it seems like it wants to understeer more at 38 psi than 34-35 psi that is what I feel on the street anyway.

ninja44

iTrader: (1)

I run 34 PSI cold and it seems like it understeers. I'm gonna try dropping it to 32 cold and see what happens.

Judder

I experimented with 40 in the front and it was too much, I got understeer where I should not have been. With 38 hot on the stock tires for me was my sweet spot.

I would start with a higher pressure then work your way down, it is also dependant on your driving style for autocross. Just keep checking the wear on your tires after a run and you will find your ideal pressure.

Terminator2

Oh, You ment hot pressures not cold. In that case, mine are 37-38 psi hot front and rear.

ogc

Precisely, however under hard cornering like autocross at 30psi you will be rolling over on your sidewalls 35, for me feels very nice and there is not much roll over on the sidewall.

I bump the back to 38 for autocross to help with rotating the rear of the car, you want it to get loose so you dont understeer.

Roadcourses I stay even 35-35 on stock tires 42-42 on R compounds.

06black

with how under-steery this car is, and has to be, i'd be at least 7-8psi higher in the rear then front.

you want the ware lines just at the edges of the corner blocks on the side walls.

to much and your loosing effective area, to little and your not letting the tire work.

Terminator2

Cold pressures or hot pressures? I never thought of running a few pounds more in the rear to promote a more neutral balance. I am getting a rear sway bar to help with that though.

xray_racer

Awesome. Thanks for all the responses. I'll be autocrossing next week and I'll report on what works best for me.

ogc

Hot pressures.

Rear sway bar will make more of a difference than tire pressures ever will and is the actual way to get that rear nicely balanced.