Originally Posted by
RickyLee53
Psi doesn't mean anything. A big turbo on 4psi will outflow a small turbo on 14psi. So it depends on your turbo/spec and how its mapped.
I think it was more the fact that a T38 is a larger, more powerfull turbo than a GT28 and both would probably be using the same (standard bar springs) head
Oh and I'm sure someone has done over 400 on a standard bottom end