Xpipe+super44's=nightmare
 

I recently picked up an off road xpipe for my 07 and had to get mufflers since I had deleted my stock ones.... Having 2 other mustangs with flowmasters I decided to go the same route but try a diff set ( both the others have the traditional 40 series) so I picked up a set and installed them. Truely I have never been dissapointed with flowmaster till now, the sound is good below 2400rpms but above that it has this horible rahsp or buzz.... It reminds me of the way a v6 with no cats would sound with 40's on it. Has anyone else awoken the buzz monster with this setup? If so what did u do to stop it haha.

Thanks in advance
John

O/R X with almost any chambered design axleback/muffler will produce a raspy sound. Either put the stock H back on or get a bullet type axleback such as stingers, bassani or maganpacks.

Put the cats back on and you are good to go!

An O/R prochamber will fix you up.

Well without changing the O/R X, get better mufflers. The FRPP GTA's or GTB's would eliminate the buzz for the most part.

Here is a video I found with the GTB's

http://www.youtube.com/watch?v=EdeWTWQkgGg

keep the flows and get some cats or an o/r h...

OR

ditch the flows and get a turbo style or bullet muffler.

I have an X with chambered mufflers, but it sounds awesome because I have cats.
(Edelbrock SDT's with splice in FRPP X. Perfect balance of rumble and rasp.)

Great!!! Thanks 4 all the feedback guys. I def don't want to sacrafice the performance benifit of having no cats so I'm leaning towards a resonator setup or even a short glasspack muffler to take some of the harsh sound away. Anyone try this yet?

yeah, i heard of people adding resonators in to tune the sound.

I actually lost tq down low when I ran with no cats. With my stock cats and H pipe, along with other mods I dynoed 298 RWHP, 308 RWTQ. With the O/R prochamber I was at 302 RWHP 305RWTQ, with hi-flows added I was 307 RWHP 312 RWTQ.

Cats dont cut away as much power as people think they just make the car a little quiter.....