The Turbo XS Stealthback Exhaust for 2008-2009 WRX and STi features a huge free flowing 4.5 inch bellmouth downpipe. From there you can choose either a catless race-pipe or a high flow catalytic converter. Both bolt directly to your stock exhaust, and is compatible with any aftermarket catback exhaust system. This allows you to customize the sound of your car to your liking, and is perfect for anyone sneak up on a unsuspecting street competitor. Or someone who wants a nice daily driver without the additional noise. This Stealthback has 90% of the gains and only 10% of the sound. Just by bolting on this Stealthback exhaust system you are a looking at around 25 ft. lbs. and 25 whp increase. If you combine this with ECU tuning you can pick up an easy 50-60 ft. lbs and 30-40 whp. The Turbo XS Stealthback exhaust systems allows you to customize the sound, and a choice of whatever catback you want to use.