[krnnerdboy]

Originally Posted by The HACK

That's interesting...

Plugging those numbers into the typical drag race calculator:

http://www.eldemoniorojo.com/calculator.htm

With muffler: 265 HP @ wheel

Without muffler (assuming ~50 lbs weight removal): 268 @ wheel

Well within statistical error range. In fact, the car weighing less sans muffler probably, by OP's account, the conditions on the launch with the muffler was ever so slightly WORSE. I guess we can safely say that the presence of the muffler makes very little statistical change in HP output (at max HP).

Which is safe to say that any muffler only exhaust making any real appreciable HP are pretty much false claims.

I don't think there is any manufacturer that claims major hp gains w/ exhaust mods...but there are claims to intake mods and the car seems more receptive to them.