Well, most spoon motors have a pretty high compression ratio but the blocks are built and the valve train is top notch so I'm assuming 10-15 psi would be okay and a stoked spoon motor puts out close to 200Hp as is it is so it would be a screamer with a turbo. Now JG can give you an engine built for forced induction duty so it too would have mad potential. There are several places you can buy pre built engines at several build levels. There is also a place in New York that sells built B18B1's for turbo duty. That would be awesome.