ErikM3.7

Hello I have a 2014 Mustang v6 I have the Roush axle backs on it and they sound great but I want them louder and want more gains. When I bought them I tried looking for some roush cat backs but they don't make those for my car. So I was wondering can I get the 2.5 mandrel piping at a muffler shop (that's the size of all the catback piping I've seen of other companies that make catbacks) and attach it to the Roush axle backs to make them into the catbacks since when you buy a cat back exhaust its the same as the axle backs just with the bigger mandrel piping. Will this work or will something go wrong. (Also I don't want to buy an x pipe or headers because I do not want to void the warranty) Thank you

PNYXPRESS

No, it wont do what you are wanting. To make your car louder you will have too:
a.) replace the mufflers with some other brand that's known to be louder.
b.) eliminate the cats
c.) change out the h-pipe for a x-pipe
d.) install long tube headers
e.) combination of the above options

yourmom6990

I don't see why it wouldn't work. You're not going to get very much louder just by replacing the tubing though. And the gains would be minimal. If you want it louder, do what Xpress suggested and go for headers and or mid pipe. The amount of money you're going to spend on having a muffler shop fabricate tubing wouldn't be too far off from purchasing a mid pipe or headers. That will get you better gains and more decibels for the money than getting the "catback"

PNYXPRESS

It won't work for what he wants because if the roush axlebacks are 2.5" and are installed that means the exhaust mid pipes on the car are already 2.5" so he would not be gaining anything except a lighter wallet.

yourmom6990

Wrong. I believe the stock exhaust on the 11-14 v6s is 2.25in. I remember this because when I went to install my cut and clamp pipe, AM sent me the wrong clamps. They sent me 2.75" clamps and they were too big. They then sent the correct ones and they fit perfect which were 2.25in.

PNYXPRESS

I thought they stepped up to the 2.5" GT exhaust. My bad.

So how is it possible to run a 2.5" muffler on a 2.25" mid pipes.

Another option is to snag a 2.5" exhaust setup from a GT. you would then just need a shop to fab up a reducer piece to bolt you factory 2.25 to the the 2.5" pipes.

yourmom6990

No, the stock exhaust is 2.25in all the way through. They are able to run 2.5" mufflers because there is a flared end on the muffler which seats the rounded 2.25in pipe properly.

You can see the flange here in the picture of an axle back. The pipes kind of butt together and then are clamped:
http://www.americanmuscle.com/flowma...ck-2011v6.html

Where as a catback system doesn't have a flange because its 2.5" all the way through. The muffler actually slips over the catback piping and is then clamped:
http://www.americanmuscle.com/magnaf...ck-1314v6.html

Now that I think of it, I'm not sure that the piping would just bolt right up to the axle back because of the flared ends on the mufflers. You would have to slice off the very tip of the flared part of the axle back and use an adapter pipe to connect the 2.5"catback pipe.. That would probably be easiest.

To answer the question, Yes. It is possible to do it with the axle back mufflers if the shop knows what they are doing.

Kind of hard to explain without being under the vehicle. lol I think your best bet would be headers and/or midpipe.

PNYXPRESS

Yeah sounds like either way the mufflers will need to be replaced or modified to step up to a full 2.5" system.

yourmom6990

I edited the above posting.

It would be possible if you sliced off the very tip of the flared part of the muffler and then used an adapter piece. It would be a fluster cluck at that point though. Mights as well just sell the mufflers and buy the whole catback system.

cruisin5268d

There's some good information already provided in this thread.

OP, it is important that you have realistic expectations and understand that your car will never have the GT sound. Some people are happy with their V6's exhaust, and that's all that matters. Just don't get false expectations and set yourself up for endless spending while you try to achieve a V8 sound - you might as well trade your car in.