Originally Posted by mrkbbd
That's definitely not true, a by-product of more power = more sound, there's nothing you can do about it if you want to "go fast", I Wanna go Fast!
The power gains by swapping exhaust alone are negligable. And certainly if you compare a quiet quality aftermarket exhaust to a loud one, I'd say the power gains are not noticable at all. There are many quality aftermarket systems that aren't illegally loud.
There's more advantage in weight savings by going to an aftermarket exhaust (from stock) than there is in power advantage.