wuz up guys, i have a question, i have an 86 rx7 N/A, and i bought the HKS Hiper racing cat-back for a turbo cause i was gonna swap my car from N/A to Turbo, now the thing is that i didnt swap it and i installed the exhaust in my N/A, now the pipping is 3 inches, is it ok for me to us this exhaust or am i losing power, i also got a bonez high flow cat. and headers, thankz!!!

 

you should be ok. I don't see why you would loose power. you still have cats??

 

I had 1986 GXL that I installed the RB header and presilencer, and it did loose some low end grunt in the low RPM's. But on the high RPM's she really gained the power. I am sure that you will find other threads if you look at some of the older posts. Good luck!

 

Well it might lose a little but with a cat you are still holding some good back pressure. I wouldn't worry.
I'm in the same boat cause I have the CorkSport single.

 

I noticed a slight loss in power when I went from a 2" dual cat-back to a 2.5" dual cat-back. I could actually feel that it wasn't pulling as hard. (this was when I was still N/A )