Looking for suggestions on intake and exhaust system upgrades. A local speed shop rep believes the current pipe diameter is a good size and that I should just change the muffler. I've been looking at AEM brute force air system (sorry haven't look at fram yet) with it's 9" air filter. Any thoughts on combination systems that will provide the proper back pressure so I don't loose any torque, it's a small motor and going to larger exhaust might reduce performance.