Hey guys, I was just wondering what average powergains are from a full exhaust? Header, 02 Housing, 3" Downpipe, and Straight 3" exhaust?

The guy I bought my Evo from put an Apexi N1 exhaust system on, then he hacked it all up trying ot get the car to pass emissions. IDK what in the hell he was thinking but he did it and now my exhaust goes from a 3" downpipe, into a 2" cat, then back up to a 3" catback. So I'm think about upgrading the entire exhaust and making my own exhaust from the dowpipe and back

 

I actually did the same thing he did. I was tired of exhaust fumes burning my eyes during the summer so I put a high flow cat on. There wasn't much of a power loss (nothing I noticed) when doing that. Oh yah, it was smoother and smelled better with the HFC on there as well. I recommend them, get a 3" if you need... but I hated my car when I was running straight pipe.

Now if you're doing a full straight 3" exhaust with what you said above, I'd say around 18-25 depending on the tune and other mods.

 

Thanks, I'm putting down around 310-320 right now with basic bolt-ons that came on the car, I'm a suspension/brake guy myself so thats what I have put my money in.. I figured it was time to show the motor some love.. 18-25 would make a large difference for me and what I do with the car

 

get a test pipe not a hi flow cat

 

I was just going ot run a straight pipe.. Where I live noise laws are not a problem and there is no emmisions testing so I should be okay.