Well I autocrossed my 2nd gen Sunday. I'm new so I kept the car in 2nd gear for most of my runs. It got about halfway up the temp gauge (s4) by the end of the run.

I have replaced the thermostat, water pump, radiator cap, and the factory underduct. On the street the car always runs a hair over C, and on the interstate it gets cooler the faster I go. So I assume there are no cooling issues. The temp increase I guess comes from the massive revving with too low speed to ventilate air up the underduct.

Does anyone have tips on keeping the car cool? I'd rather not install electric fans or anything so I can stay in a stock class for now. Should I pull the thermostat before runs, or any other tricky ideas?

 

If the temp went to almost 1/2 during some demanding driving conditions, then I would say that you have nothing to be worried about. However, during normal driving it sounds as if it is running a little cool. What brand of thermostat are you running? temp?

 

I'm not sure on Autocross rules, but get a real temp gauge if you can. Put some 40 Below radiator additive in with distilled water - much better than Water Wetter. It'll set you back about $25 but it's good stuff. There is a 160 thermostat from Atkins, I think most thermostats are 180-190, that should get the water flowing earlier. What RPM's are you turning, possible pump cavitation? You probably can't change pulleys anyways in stock, I don't know.