Originally Posted by MrFatbooty
The plain and simple fact is that a GSR with a bolt-on intake, header and exhaust (and a non-clogged stock cat) will put about 155 hp to the wheel. Adding a high flow cat to the mix will produce...surprise surprise, about 155 hp to the wheel.
I would indeed be surprised, but do you have a graph that actually shows zero gains from swaping out a stock cat for a Carsound on a mildly-modified GS-R? I'm actually very interested in seeing one, because finding a direct back-to-back comparision with the cat as the only variable is not an easy task. Most people either retain the stock cat or swap header and cat at the same time, making it difficult to break down the gains. Something like this would make an interesting test if someone could locate inexpensive dyno time.