I think my turbine side is .63, I'm not sure aboutt he compressor. But if you want quick spool, smaller is better on the hot side, but there is more back pressure, so your top end wont be as good.
If you want your power to be there very quickly when you his the gas, go for the .48. But that gives you more back pressure, and the top end power wont be as high as with the .63.
If you want your power to be there very quickly when you his the gas, go for the .48. But that gives you more back pressure, and the top end power wont be as high as with the .63.