I'm doing the local PCA AutoX this weekend and they are calling for intermittent thundershowers. I'm running a stock 914 with street tires. Usually I run my pressures around 34-35 psi. I'm wondering how I should adjust them if it is raining or just wet? I've got a solid deep tread on these and they are 205/60/15's. Is there a general rule to follow?

THANKS!

General rule is to use more pressure in the rain, but generally refers to tires w/ little to no tread so the profile of the tire is more rounded to push water out to the side. For street tires w/ good tread, its not so critical. Depending on sidewall stiffness, I'd say your playing in the right ballpark with your pressures.

Good luck and have fun at the autocross.

After your 1st run @ 36 PSI make a radical jump to 40 and see if it's better. Heavy rain with puddles = more pressure, just a wet or damp surface you can run them normal.
225/50-15 with 1900 pound car Hankook RS2 likes 36-38 PSI.