Autocross Tyre Pressures
Thread Starter
Drifting
Joined: Jul 2002
Posts: 1,254
Likes: 1
From: Edinburgh
Autocross Tyre Pressures
Hi Guys,
I'm considering taking my car to the track for the first time in the next week or so and wondered what I should be thinking of in terms of tyre pressures. My tyres are 245x40x18 and 275x40x18 Pirelli P Zero's.
Thanks
I'm considering taking my car to the track for the first time in the next week or so and wondered what I should be thinking of in terms of tyre pressures. My tyres are 245x40x18 and 275x40x18 Pirelli P Zero's.
Thanks
Race Director
Joined: Sep 1999
Posts: 11,361
Likes: 383
From: Plano TX
You have good tires so you don't have as much to worry about as far as sidewall flex as the ones running stock tires.
That said, as a starting point I'd probably go with 38 PSI front and a few PSI less in the rear... about 35. Chalk your tread including a little bit onto the sidewall. After the first run you can look at the chalk and see if the tires roll or not.
You can then fine tune handling with the rear tire pressure. Increasing it will make the car understeered and vice versa.
Have fun!
That said, as a starting point I'd probably go with 38 PSI front and a few PSI less in the rear... about 35. Chalk your tread including a little bit onto the sidewall. After the first run you can look at the chalk and see if the tires roll or not.
You can then fine tune handling with the rear tire pressure. Increasing it will make the car understeered and vice versa.
Have fun!
on suggested pressures.. Good luck and have fun.....
Melting Slicks
Joined: Dec 1999
Posts: 2,116
Likes: 156
From: Mid West
Cruise-In III Veteran
I agree with zwede, start there and make sure you have an air compressor or one of those air tanks. I had slight oversteer on the road course, and ended up running 40 psi all the way around. I think your tires are slightly shorter than mine (255/50 17's), so you can probably get away with a little less psi. Even with 40 psi, I could see a small amount of scuffing on the side of the rear tires .... maybe 3/8-1/2".
Have fun.
Have fun.
