First of all, the desired exhaust size for a turbo engine is about 3", correct? Second, would it be ok to put a resonator (probably about 20"-24") on the cat-back, or would that cause too much backpressure?

Thanks in advance...

 

It gets loud as hell without the resonator with 3" even with a highflow cat.

 

I'm not an expert but if u put a 3 inch resonater, its not gonna make any difference in back pressure than 3" pipe. I'ts just gonna quiet it.

 

correct soulfly99 as long as the resonator is a race type. some resonators shrink the inner diameter or have restricting slots in the internals. I am using one from summitracing.com, dynomax. It helps tremendously.