Expect about 12hp at the wheels from a Y pipe (20hp if you have a supercharger).

As for the exhaust, the general consensus is it really isn't necessary, as the least restrictive systems only yield around a 5hp gain.

Alot of people think the noise from the exhaust (such as the GReddy) is too much, but IMO they sound goooood

So...I'd recommend the Y pipe at the very least. As for the exhaust system, its up to you. Do you want a rumbly exhaust? A racier look? If you want both get the GReddy. If you low restriction with a relatively quiet muffler, get the A'Pexi WS system. If the only thing you care about is the look, save the $$$ and get universal muffler

Happy modding

 

this was meant as a reply to papichulo_001's thread about exhausts..

heh..doh