I'm posting this here because I want to hear from turbo guy's that have the fmic and/or same kit as me. This way our rad. situations are the same.

So does anybody have a clue as to my overheating problems? I have a star stage 2 at 8psi. When I'm at highway speeds and I turn on the A/C it overheats. It never boils over but the guage goes up past 3/4 of the way to hot. If I don't have the air on it won't happen unless I'm really pushing it hard for like 1 hour or more. I have replaced the thermostat with the 160 degree, flushed the cooling system, and replaced the rad. cap with the gst's 13psi cap.(plus I use watter wetter!!!!!) Where the F should I look next. this is driving me nuts. I know some of you guy's out in the desert or in FL are in hotter conditions than I am. What the hell can I do now? coolant temp. sensor, guage what should I do guy's I'm at the end of my rope here. Also the compression is just fine I had a 205 / 205 / 210 / 210 comp test on the stock bottom end. I'm really flipping out here.
P.S. On the way out to the howell open house we were doing some mountain climbing in the cars and it got hot on just about every major hill. It seems to be only under high load like the A/C being on or me really pushing it or climbing hills.

I was having the same problem. I think I may have fixed it so far. I ended up pulling my radiator out and it was filled with crap. I couldn't even see through it so we took it to the car wash and washed it all really good and put it back in and so far the overheating hasn't started back up. Might be something for you to check out.

Yes, be sure your radiator is clean, and also be sure you pass side fan comes on when the A/C is on. That fan should ALWAYS be on with the A/C..