I'm going to give it to you straight. As long as you are going with a strong tuning company like Greddy, Apexi, Skunk2, Spoon....etc....they'll all be the same as far as making power. Also, don't expect too much power unless you've also done headers and intake. That said, the reason they're all going to be pretty much the same is because they're all mandrel bent tubes, and all 2.5 inches or 60mm...which is perfect for non turbo cars. If you ever go with a turbo, you'll need to buy a turbo exhaust which is usually 3in or 80mm....from Thermal Reseach or a custom shop. If you are not going turbo then there are only 3 things you need to look at. 1. The muffler type and resonator. The canister style muffler exhausts without resonators will drone quite a bit, and be a bit louder, but will only net 2-3 extra horsepower over a simple sports exhaust system from any other company unless you've got a built motor and cams...etc. Some people prefer the deeper quieter sound from the non-canister exhausts.2. The look of the exhaust. Do you like it? I hope so because it's what you'll be starting at. :-)3. The WEIGHT. Since most systems will give about the same gains, look at weight. Some are made out of stainless steel or aluminum...and some are made from full titanium, which can save up to 40lbs on an RSX Type-S. This can be a noticable difference in performance.Other than that, I can't think of much else to tell you. Probably the most well engineered exhaust system for the RSX was from Toda Racing. With a good Cold Air Intake system, the Toda Headers, and Toda exhaust and a mild cam...they made an additional 56whp...which is pretty huge for a non turbo car. I'll leaves some links to check out. Good luck with your decision!www.opakracing.comwww.kingmotorsports.com
http://todaracingusa.com/onemake?id=...x/performance/