if i put a RMM downpipe w/o cat and a Tanabe cat back system on my supra how much of an HP gain would i see at the rear wheels? I'll be also be putting on a highflow cat just to keep me sorta legal and for the added back pressure for torque.<br><br><br>Thanks

First, with a turbo car you don't want any back pressure. No matter what anyone tells you, you don't want back pressure. The addition of an HKS cat back system (similar to yours I guess) yielded a total of 35 RWHP according to Turbo Magazine in 1987. If you get rid of both cats it should be more. If you haven't installed this exhaust system you're talking about yet, be prepared as it will make a very significant difference at 11 psi or more.

ok so no back pressure...hmmm....so what about the cats then...i'm going to have to stay legal. So with one cat it shouldn't too much then right