i know it does ruin handling on alot of the cars that you change the egnines in, like 280z with v8, its probably only going to be good on a 1/4, but some cars it would be fun on, and i dont think forza is going to put much studying into their cars, they probably just made the cars 'how they think' it would drive, with engine swaps, it would probably be unreal, like good handling, with lots of power on that 240z with v8, but i dunno yet have to see when the game comes