Fast Motorsports 3" Catback exhaust for 2008 to 2010 WRX Hatchbacks keeps your motor breathing freely by introducing full 3" stainless steel piping into the system for better throttle response and more power. Fast Motorsports systems come fully mirror polished and include everything necessary to bolt directly on to your WRX. The muffler is subtle, yet will still turn heads and will provide an exhaust note that matches perfectly with the sleek look of the latest generation WRX. . This system has it all - from looks to performance, not to mention one of the most attractive price tags on the market.
The stock exhaust on my 2008 2.5i hatchback completely rusted off thanks to Ontario's harsh winters and liberal application of road salt. I bought this kit knowing that a full 3" catback is entirely too much pipe for a stock NA 2.5 litre engine, but that I'll be able to take advantage of it once I get around to pulling the engine and doing cams/heads/intake/cat next spring along with the 100k mile maintenance schedule. I expect this stainless exhaust will outlast the car.
Here's what you need to know to put this on a 2.5i:
1) The 2.5i differs from the WRX where the catback bolts onto the cat pipe. It is a 3" pipe, but the 2.5i uses a flex gasket with spring tensioned fasteners. The included M10 bolts will not work, and the stock fasteners are not long enough to thread through the thicker flange that this kit has without modification. You may need to purchase a new gasket, depending on the condition of the OEM one. You may want to purchase longer spring tensioned fasteners, instead I cut 2 coils off of the OEM springs which allowed me to use the stock fasteners.
2) The heat-shield above where the stock resonator sits will touch the new 3" pipe. It is malleable enough that you can reshape it with a ball-peen hammer to clear the pipe. Alternatively, you could remove the heat-shield and wrap the pipe with heat-tape. I did this since I was removing the catalytic converter's heat-shield and wrapping it at the same time anyways. This eliminates the 1400rpm rattle the 2.5i is infamous for.
In stock form, this catback is too much pipe for the 2.5i. The muffler is too loud for how slow this car is, and it is droney under partial throttle from 1400-2000rpm. Especially with the automatic, you hear droney resonance every time the torque converter unlocks and the 4-speed starts to downshift. It does sound great above 4k under power, and I notice it carries smoother to redline than the stock exhaust. I am considering installing a muffler silencer with a 2...