I'm looking into cat-backs as one of my first mods for my 2013 V-6. For now, let's assume the current crop of 2011-2012 V-6 exhausts fit the 2013s. Sound laws are strict in my area and my autocross club also has strict noise limits, so I'm not looking into anything unmuffled.

My question is, are there any real power, gain, torque gain, or weight loss differences between any of the different brands of cat-back exhausts on the market? So far it looks like they all about the same. From what I've seen only Flowmaster and Dynomax list any dyno charts and I haven't seen any user dyno charts that cover a stock car with a new exhaust (there's always some other mods in the mix). It's not a big deal if they are all about the same, I'll just choose based on sound.

 

Hp gains from axle back only upgrades are negligible. Choose on sound and or lack of drone.

The biggest performance gain in my experience was actually the weight. You would not believe how heavy the stock mufflers are.

Sounds like you have a hot car on order, enjoy!

 

I figured not. Thanks for the advice. And yeah, I can't wait for my Mustang to arrive!

 

The stock exhausts are huge and heavy. Replacing them alone should garner some weight advantages.

If you really want performance, go headers.

 

What he said. Sound and weight reduction are the only real gains. You might pick up 5-10hp, maybe. Removing the cats is really what's providing the gains. That may or may not be legal where you live and will also increase the noise. You would need a tune to take full advantage of off-road x-pipes or LT headers.

 

I still have cats -- albeit, highflow cats -- and made great gains, with my LT Headers. So if you have any concern for the environment, you can still keep your cats and make some decent power with a full exhaust.

 

Yeah, I've got a muffler guy and we've talked about basically replacing the piping to the cats and replacing the cats with some Pypes ones. I'm guessing I might find a few extra ponies but nothing to re tune for.

 

I plan on autocrossing my car in SCCA D Stock, which allows me to replace the stock exhaust only from the cats back. If one exhaust had a major advantage over the others I would have gone with that, but since they're about the same I'll just go with whatever I think sounds best. Thanks again.