I want to upgrade my cooling system without a new radiator. I don't track race, but i do drag race now and then. I also punch it all the time on the street. Where i live it's at least 95 degrees from Mid May to early Sept, so i know it couldn't hurt to upgrade. I've seen a lot of posts saying the nismo and billion thermos run to cold, unless your running at the track alot. Some people have koyo's/howe's radiators and nismo/billion thermostat and say no problems. Why would a 12-22 degree coolant temp drop hurt the car? How much would a nismo thermostat help with a stock radiator?