I have a 2010 GT with Roush Cat-backs. Love they way they sound and I'm considering a couple of things to enhance the sound.

First of all, I'm not interested at all in how much HP I can attain. I'm looking more for a sound upgrade than anything else. Additional HP would be a bonus.

What sound difference is there in just installing headers and not changing out the mid-pipe?

I've listened to several youtube videos and read a lot about x-pipe vs. h-pipe and decided I like the h-pipe sound better.

One thing I've noticed when perusing the various vendor sites is that the h-pipes that are sold are shortys designed to go with LT headers.

Has anyone installed only headers? Do you like the results?

 

pypes makes h pipes for shorty headers or stock manifolds
summit and jegs also make an h pipe for shortys


so by headers only, you mean shortys, bc LT's need a matching midpipe.
shortys only may get you a little louder and deeper, but not much.
you'll make more of a difference in sound and loudness with an o/r mid pipe vs shortys.
and the midpipe is cheaper too.

so you have the Roush extreme catback?

 

Yes, I have the Roush extreme catbacks. No mufflers...just resonators. Love the way they sound, but wouldn't mind something a little louder.

And I was mainly looking at shorty headers. There is emissions testing here, so I'm in need of cats unless I want to swap out prior to inspection each year. Not sure I want to do that.

Would a high-flow cat H-pipe be a better option over shorty headers?

 

the high flow catted h would be another option, i'm not sure if it would be louder than shortys.
but it would be an easier install.
would the hi flow catted h still pass emissions?

 

There is a guy on fnsweet.com (Dimora) who put the Mac long tubes on with their shorty mid pipe and custom fit it to hold high flow cats. Long and detailed How-To with pics and a video.
So, it is possible to have long tube headers and cats.

 

I put JBA shortys on my 08 Bullitt and I could not hear any difference at all in the sound.

 

you could also buy a catted mid pipe for LT's, but mac doen't make a catted prochamber.
i think thats why Dimora fabbed his prochamber.

having LT's alone may fail inspection.

 

Thanks for the replies everyone.

I'll probably pass on shorty headers since they may not offer much difference in sound.

Probably go with some cams instead.

 

Cams aren't going to change the sound as far as volume is concerned. I put a set of the JBA shorty headers on mine and it did change the sound slightly..... a little louder. I then added a set of the MRT hi flo cat / H pipe and that did make a big difference when you step on it. I am also running a Whipple and my boost dropped by a half a pound which means they really do flow more.

 

I cut off the stock H pipe and installed it behind the high flow catted downpipes from my Magnaflow X pipe and I love the sound (especially with my chambered mufflers). I had the X pipe with these mufflers now and it was definitely not as throaty.


Pypes makes a stainless off road H that you could put some high flow cats on to keep the volume down. All the others I've seen are aluminized unfortunately.