will fitting an sti exhasut to my wrx give me any performance gain or i am better off going for an aftermarket exhaust ?

 

hayward and scott is the way to go.sti system wont add much.

 

Aftermarket exhaust everytime will give a performance gain over o/e system. A prodrive system will give a slight gain if you don't want a loud system . Failing that the likes of Haywood & Scott , miltek,cobra, blitz, etc all make pretty decent systems that are more free flowing than the STD exhaust system .