im going to be putting a catback on my car.(06 ex). i was looking at the underbody to get an idea for piping and size. The cat is basically right at the header, so my catback is gonna be super long. is this benificial or not. im going to fab it all myself, but with the cat being where it is, im not sure whether or not to start right after the cat or start a little farther back. any suggestions, i have a friend who works for honda and has a hondata tuner. With a CAI, cat back and a good tune, what kind of gains am i looken at.
thanks