skeetshooter

My bone stock 997 has Michelin PS2 tires on 19" Carrera Classic wheels. What cold tire pressures should I used for those tires at an autocross and what hot pressures should I maintain?

How much tire life am I going to lose?

It's been years and years since I autocrossed on regular street tires...

Thanks,

Scott

KenJ

Since you implied you've AX'd on stickies, you've probably already got a good idea that with a bone stock set-up and not too much camber, you're going to hammer the outside shoulders with real aggressive driving. One very aggressive day (4-6 runs) and you'll 'notice' the outside wear. Now that you got the 19s, it gets a bunch more expensive to replace rubber. If I recall, the PS2 are asymmetrical and once you've scrubbed the O/S shoulders, they can't be rotated inside/outside to get use of more of the tire.

Anyway, not having the 19s myself - I've AX'd on 17s with SO3s, PS2s and Yoko Neovas. The PS2s in my size seemed to need a bit more pressure to keep from rolling over on the shoulders excessively. According to the TireRack stats., the PS2s are much lighter than the other 2 and I can only attibute to a little softer sidewall - hench my theory about needing a little more pressure. I used hot pressures between 40-42 lbs (sorry, for a Boxster this time). If you're playing with PCA, you'll have a full day and can expect cold pressures to climb quite a bit from AM to PM as the AX site heats up .... 6-8 lbs?

I just tossed that out for thought - and would also like to see who's out there AXing on 19s.

Good luck,

kj