where can i look for some tec article in exhaust system comparison test for eg+c5

 

It's really simple actually.

The larger, and smoother the flow the better. (Stop at 3 inches)

IF the exhaust has a resonator it will slow the flow.
If it doesn't have a strait through muffler it will slow the flow.

But, if it does have no resonator and a strait through muffler it will be loud as hell.

 

i was looking for either apexi n1 or tanabe hyper both cat back for eg w/c5 motivator. is there any difference between these two?