What is faster a toyota supra or mazda RX-7 both of them have 25,000 put into it.?

You need to talk to a professional on each of these cars, but I would say they're about equally matched. The Rx-7 is one of the best handling cars ever made, but has a rotary engine which can make do it yourself repairs difficult. My best advice is just make sure everything is done professionally, turbos are nothing to play around with, a bad set up can mean a blown engine real quick.