[stonenewt]

Originally Posted by nikitopo

Changing just the exhaust won't give you more power. OEM exhaust is pretty much open for the NA engine. Why so many companies think they are much better than the factory? This is nonsense. By changing the exhaust, you'll get just a better sound.

Or maybe not

... you need to replace the second cat pipe and back to see gains on the BRZ and GT86... ...the manifold back road system [second cat, resonated mid-pipe & back box] delivers an extra [in addition to just the exhaust manifold] 5.3ps. On their own none of our road or race exhaust components liberate more than 1ps when placed in the stock exhaust system