The Revolution RS for the Subaru WRX/STI sedan features full 3.0” diameter piping for superior performance. Dyno test have shown increase in 12hp and an amazing 32ft-lbs of torque. The purposeful single-sided cat-back layout with minimal bends produces a cost-effective, light-weight system. Classic GReddy styling positions the muffler and tip stylishly underneath the right side of the car while matching the profile body-lines perfectly. Like all GReddy Revolution RS systems, the exhaust is made from fully hand-welded 304 Stainless-Steel and carries a Limited Lifetime Warranty.