Need New One

Getting ready to purchase an 06-GT automatic (will be my first automatic Mustang, Hmmmm, We'll see.) Anyways, the car is too loud for my preference and probably my neighbors. I've attempted to attach an AVI file so you can hear the exhaust.

When you combine BBK long tube headers, cat delete, Ford Racing cam, Pro Chamber Mid Pipe (which I do not think constitutes a muffler, but I don't know), you get a loud car which is cool, but not for a car I actually plan to drive. The current owner has put 2k miles on the car in the past 4 years.

So I want to quiet the car down and I know I will be giving up some HP. The shop that did all the after market work for the current (soon-to-be previous) owner suggested installing a catted-x pipe and said it would quiet the car considerably.

Can anyone throw out a decent percentage reduction in sound just by adding the catted x-pipe? Would this alone reduce the volume by 25%, 50% or 75%? If the car is still really loud with just a catted x-pipe, I may want to install mufflers as well but I think I need to decide now, before the catted x-pipe is installed, just to keep costs down.

If I do add mufflers, any specific muffler suggestions for a mildly aggressive sound considering the other mods already done to this car?

Dino Dino Bambino

You won't give up any HP by adding a pair of mufflers which, incidentally, is your best option rather than a catted midpipe. Since the car would remain catless, go for a pair of chambered mufflers as these would do a better job of cancelling out the sound. Straight through mufflers will be louder and raspier.

Need New One

Thanks Dino Dino Bambino but I want it to be street legal so I need the cats

ghunt

High flow cats will help some with the sound, but you'll want mufflers on there too.

I don't know about chambered mufflers though, because I was running some for awhile and the drone sucked. My current mufflers are big case, perforated core straight through mufflers. They sound good (only really loud at WOT), drone is much better, but they are not cheap (I found a really good deal on mine on ebay, but normally they are expensive since they are Borla).

The core problem is that most axle backs are designed to sound good with stock cats- once those are gone, they are way loud.

Dino Dino Bambino

Then you can add a catted X-pipe as well as the aforementioned chambered mufflers.

Derf00

Depending on your states emissions regulations, just having cats on the car may not be good enough. Double check with your state if the Cats have to be CARB certified. Just check withy any smog shop and they'll be able to tell you.

2007CalSpec

I had an off-road prochamber mid-pipe with MAC boomtubes which were basically muffler deletes with baffling. I hated the trumpeting so I switched to Mac mufflers. The sound was awesome. Deep and throaty. No, not deep throat. Deep and throaty. :-) I heard x-pipes don't sound good with chambered mufflers. X-pipes are better with straight through mufflers. This is what I have now. For your setup I would keep the prochamber and just add MAC mufflers and cats.

Need New One

So the shop is recommending the BBK catted x-pipe as it pairs well with the BBK long-tube headers that are on the car. Now I need to know what muffler to install. The catted X-pipe should reduce the sound but now what mufflers work best with this setup for a deep, classic muscle car rumble?

2007CalSpec

Have you seen this thread? It might help.

https://mustangforums.com/forum/gt-s...nd-thread.html

Dino Dino Bambino

In some states (e.g. CA), long tube headers aren't smog legal and the cats are required to be in the stock location, so you might wanna check for that too.