Originally Posted by S.C. Express
dual 3" pipes would kill your power. A single 3" pipe would be fine. You don't need a full 3" dual exhaust unless you are running a 500+hp big block or running boost. It's dyno proven that high boost aps need larger diameter exhaust. I've seen 4 cylinders with turbos running 3 1/2 to 4 inch piping making around 400 hp and tq to the wheels.
As for the resonators, they are not restrictive. You will see no gains from removing them. They just help minimize drone, thats it.
I meant 3" from the muffler back. Not the manifolds.
I wouldn't expect any gains, my main concerns were the resonators or whatever I could guess they were at the time being more restrictive emissions junk. I'm sure 3" after the muffler would change the tone a bit though.