Im thinking of upgrading my stock muffler to a Flowmaster Super 44 Delta Flow muffler. I was aiming for an aggressive sound but not so much as loud. Im wondering if anyone knows the size of the inlet and outlet diameters of the muffler? As well as what size muffler to not make it loud, if possible? Thanks

 

I wouldn't do it, if I were you. Go with the Magnaflow. I had the Flowmaster on my Xfire and the resonance inside the car was terrible. It was deafening between 2,000 and 3,000 rpm. So, freeway/highway driving was not enjoyable. The Magnaflow sounds better on the outside and does not have the resonance inside the car. If you go to youtube and search Crossfire 12158, you can see and hear my car with both the Flowmaster and the Magnaflow mufflers.

 

I dont really like the magnaflow as much. Sadly, since i know pretty much everyone that has upgraded their exhaust has went with magnaflow or custom exhaust. I read on another thread that installing dynomat in the trunk decreases the resonance alot. I'm really on the fence about the whole thing..

 

I have the magnaflow 12158 and really love it, much more "expressive" than the stock exhaust note. I'd recommend it, but again, its all a matter of personal taste. In the end, the exhaust was cheap, but twice as expensive to have it installed with the use of the oem tips, but, that being said Im still happy with it and it feels like it picked up a few extra HP's.

 

I installed the Magnaflow 12158 with Borla Performance tips ! Really like the exhaust note at WOT ! (Sounds like a Formula 1 from a dig outta the pits) The only drawback is a drone inside the cab between 2200 and 2800rpm when cruising.
Got in the habit of downshifting or kickin the tunes up to 40 when the drone becomes something I don't wanna deal with !

Just my Dos Centavos