why bother witha catback? do a turboback with a grimmspeed downpipe and get tuned to stage 2! stage 2 08/09 wrxs get near 350 lb/ft of torque with itty bitty bolt ons!
I agree with the previous comment about getting a Turbo back system, not Cat back. Exhaustsuk.com (Sheffield) fitted full Turbo back 3" stainless system including competition CAT, 3 flexible pipes and twin pipes at back for £780. This was for a Saab 9-5 Aero (don't laugh) and it made a HUGE difference. If you fit a CAT back you'll only get more noise and not a great deal of extra power. I gained 40BHP, have a rust proof system front to back, and they specialise in Imprezas and have off the shelf systems for them. Give 'em a click on the interweb and have a look. If you're in a country outside Britain though, I don't suppose this helps!!!
Search Subaru Impreza WRX Questions
Subaru Impreza WRX Experts