rdcpgh

I think I made a costly mistake today, and would be appreciative of any helpful advice. I had the Magnaflow Competition Catback installed on my 2011 GT today. It is intolerable. Between 1600 - 2200 rpms the drone, pulsation, vibration, and overall din is horrendus. It sounds good when starting the car up and when jumping on it with the RPsS pushing beyond 4k. But just normal driving around the city, stoplight to stoplight, RPMS in the 2 to 3 range most of the time, it is a terrible experience. I enjoyed this car alot more prior to today.

(1) Can any fixes be applied to eliminate or at least tone down the drone.
(2) What would the effects be of adding a catted x-pipe?
(3) The mechanic put this on easily and quickly. Would it be equally as easy and quickly to revert back to stock?
(4) Is it the tubing or the mufflers which cause the drone? or both?
(4) The tubing leading to the these mufflers is 3 inches. Are there any muffler kits that would fit this tubing and which might might tone down the noise/drone/vibrations, etc.?

Any thoughts would be appreciated.

wonger

I'm guessing the lack of mufflers is your problem. If you only did the axle back, you still have two cats and two resonators. If you have the cat back you have two cats and that's it.

Try some dynamat and or fat mat etc. In the trunk before you freak too much. It's like a big popcorn tin back there. You may be able to change the resonance in your car by that.

c0achmke

Mine were not a bad as you are saying but I had a lot of bass sound and rumble through the mid pipes. I put on an x pipe and it smoothed everything out. Cut drone way down just a nice throaty sound now.

newpony

I had terrible drone on my car (V6) after installing the Bassani Axle-Backs. I almost god rid of it until the exhaust shop put two Maganaflow resonators to quiet things down. Now I can cruise above 75+ MPH with no problems. You should give it a try.

rdcpgh

I have been thinking on the x-pipe, and from your story it sounds like that might be a fix. Did you have the same system? The Magnaflow?

c0achmke

Well mine is a 2010 but yes magnaflow cat back 3" and tru x pipe.

rdcpgh

I was really thinking about that being a viable option prior to your thoughts, and I am now willing to give it a shot after hearing your story. i spent this much money already, another $400 won't kill me. Just want to lessen the drone, lessen the deep, bassy tone, and lessen the pulsations, vibrations running throughout. I will give it a shot.

2010GT

It really just sounds like you don't love the tone of the exhaust . I wouldnt get nuts and keep adding resonators. Take it off sell it lose some dough and replace it with an axle back.

zcgstang

Give it some time. Let it all settle. I had the same with my muffler deletes. With time I.notice it Going away

Ethanjbeau

I have the same exhaust and I'll tell you now the drone will get worse in about 500 miles or so. I however dont notice any drone while in the city, just exhaust noise. On the highway between 1800 -2100, its terrible. So I try to stay out of that range. The only other thing you could be is switch out the mufflers for the street series mufflers. That will definitely help but change the sound.

rdcpgh

Thanks. I did not install an x-pipe. It is still the same stock H pipe. do you think adding the catted x-pipe would help at all? right now, the car is no longer fun to drive. I am not willing to trade my desire to run the car for a great exhaust note at startup at WOT.