Tire pressures for cold weather.

[B13SER]

I have an autocross coming up tommorow. Looks like temps will top out in the high 40's with a wind chill factor so it will feel much colder. I have access to Nitrogen to fill my tires with What would you recomend as a starting point for pressures?

I am driving a 93 se-r with #350f and #250 rear springs, stock sway bars and 3 deg of camber. Tires are used/shaved RA-1 205/50/15 I usually start 35 all around and work it from there. We will be getting probably 8-10 runs and should be able to get "some" heat in them. I was wondering if I should start low to get some squirm in them and maybe generate a bit more heat or higher to punish them just a little.

[kbrew8991]

it was around that cold for me this weekend at CMP, I still started with my standard pre-session pressures and the tires felt fine all session (lap 1 through end)

[B13SER]

I had them at 35 f/r and that was crazy loose. So I dropped the rears 5 and for the most part that felt pretty good. There might have been a little bit more time in the set up, but I still think I got a top 5 overall. I got lucky. Everyone got lucky we didnt get blown away with the wind. Man We had gusts over 50mph.

[RacinDavid]

I have an autocross coming up tommorow. Looks like temps will top out in the high 40's with a wind chill factor so it will feel much colder. I have access to Nitrogen to fill my tires with What would you recomend as a starting point for pressures?

I am driving a 93 se-r with #350f and #250 rear springs, stock sway bars and 3 deg of camber. Tires are used/shaved RA-1 205/50/15 I usually start 35 all around and work it from there. We will be getting probably 8-10 runs and should be able to get "some" heat in them. I was wondering if I should start low to get some squirm in them and maybe generate a bit more heat or higher to punish them just a little.

I would start near 28 with an RA-1. Do you have a temp gauge at all perfect is around 200 degs? You could check after the first run how hot they are getting and also check and see if the wear is creeping into the sidewall; all basic stuff you already know. You should be able to notice if that low of a pressure is a problem on turn in but it should be fine. Used and shaved are a big difference. The compound gets harder after too many heat cycles where as if they are shaved you won't have that issue. None the less a road racing compound is going to be like ice no matter what you do...see if you can find a co-driver.

:cheers: