my car when it was running(the one on my avitar to the left) would over heat when I started running it hard? like instantly. I would get maybe one good 50-90mph pull when I was racing on the freeway, then my car would run really hot and my power went way down. Any Ideas?

 

Basics....are your fans running? Is your air dam in place? What temperature is it hitting?

 

even more basic, check the coolant level.

 

check your fluid lvl, make sure you get your system flushed get any of the junk that might be built up in it run it with the cap off to make sure it looks to be flowing properly if your thermostat is stuck shut it may not allow enough flow to keep it running cool also take a hose and if u can spray from your engine compartment out the front through your radiator to possibly clean out ne build up thats in there to help air flow

and as a reply to the well reply about your fans running my 91 rs has electric fans that the relay gave out on my way to tennesse (650 miles drive) and i lined up with a nissan 350z 120mph and no problems overheating it just couldn't sit in one place for long

 

Mine did that when the head gasket was blown.