I see what you guys are saying if I keep everything else stock, but I have plans to do some upgrades on the intake side of things as well. This isn't just a "I-wanna-put-a-Flowmaster-and-3"-pipe-on-'cause-I-want-it-to-sound-cool" idea. I want it to flow well, and with the increase of air coming in, I want to make it easier for that air to flow out. What other performance upgrades are avaliable for the Renix setup?