2.25 mandral bent pipe with a magnaflow muffler...noise depends on resonators...get a long one, the less noise will come of it....2.25" will be good until 210 crank HP...get a 2.25" cat and a new header as well....you want to keep backpressure at a minimum and most aftermarket exhausts don't offer this....most aftermarket exhausts aren't a true 2.25" throughout..they have a bottle neck somewhere along the bent...usually where it connects to the cat...I know most tanabe exhausts have this..necks down to 2" or less...essentially bottlenecks the exhaust flow and creates unwanted backpressure...you want no backpressure, people that tell you otherwise are dead wrong...most aftermarket exhausts yeild 3-5 psi..and this is for a good one