Why is my mountune cat back droning?

[bobjob]

Same set-up. It is loud but not a resonant drone. One thing is cap off the Sound Symposer. The Symposer works great with the OEM but is off frenquency with an after market CBE. Once I did that the Mountune was nice, deep, rich and burbly. And sounds Angry when you WOT. Sweet love.

Ahh good to know, Ive had the DHM plug for months but dont have the tools/time to install it. Maybe I can ask the guys that install the catback to do it while its lifted

 

[lx93]

Same set-up. It is loud but not a resonant drone. One thing is cap off the Sound Symposer. The Symposer works great with the OEM but is off frenquency with an after market CBE. Once I did that the Mountune was nice, deep, rich and burbly. And sounds Angry when you WOT. Sweet love.

Thanks that's worth a shot. I will try capping it off and report back as soon as I do that. Can you still hear the sweet blow off noise when you lift off the throttle like with the stock setup? I love that noise and it is kinda covered up with the louder mountune setup now

 

[bobjob]

I got my mountune catback installed saturday. I guess you can consider it droning if you keep the rpms at a certain threshold ( playing with the throttle) but its usually short since you rev past it quickly. at least that's what i notice. I got the cobb hangers too fyi, and have the DHM symposer delete done.

 

[D3 SS 3D]

Had my Mountune CBE put on last Wednesday (+ Cobb hangers). The day of and after it was pretty loud (seemed like), but this week it’s a little more subdued and deep tone’d. Not sure if there’s some type of breaking in period. Also, I’m really enjoying the deep tone of this exhaust and I’m happy that it doesn’t sound like the typical “fart can” running the streets. As far as drone, it really doesn’t have much when cruising or at steady speeds. However, get on the throttle and you’ll hear it. This CBE will do nicely until the weekend when I get in the GT500 and hear that beauty.

 

[InsTwin]

Yeah, I experienced similar things for the first 1000 miles. Once you get some carbon build up, it really leveled things out.

I have the MAP exhaust on Kartboy hangers and it sounds great when I want it to, and makes almost no sound at idle (idling at 850rpm, higher than stock but lower than alot of tunes).

On the highway, there is no drone unless I'm on the throttle.

 

[lessard.dcj]

My MBRP would drone on occasion so badly i had to pull over because i couldnt take it any longer.

i decided to investigate the issue and found that the exhaust tip had some sway to them under light pushing from my hand, so i figured while driving the engine and exhaust would move enough for the exhaust tip to make contact with the bumper cover and that would allow the vibrations of the exhaust to resonate through the entire car BADLY!

i pushed the exhaust hanger rubber over a little and put a small worm clamp in the hanger bracket to stop the exhaust tips from creeping over under driving conditions. my car drones no longer and sounds so sweet.

hope this helps

 

[Siestarider]

I have what used to be an MBRP and is now a 3" custom with Vibrant resonator and muffler, both straight through. Single tip. Drone around 3K was horrible, boomy, so I found a used "resonation damper" in the trash bin at muffler shop, supposedly off an old Mercury Marquis, used a 3" clamp to clamp it on above and just upstream of muffler, tamed drone. Muffler shop said it would not work, but it did. Big difference.

I still want to try moving it around to different places, but it worked well enough first shot I have not got around to it. Now I am going to grease hangers next time under there.

 

[John9851]

Guys, I'm new to all this so I hope this isn't a stupid question but how many Cobb hangers would I need for this application ?

 

[bobjob]

its ~$45 for a set of 3 if you get the cobb set.

 

[DP03]

Guys, I'm new to all this so I hope this isn't a stupid question but how many Cobb hangers would I need for this application ?

Well, the car has 4 hangers. The Cobb hanger kit has 3. I will never understand why Cobb shorts one on their kit, nor do they have a logical explanation (I've asked more than once). That being said, I have the Cobb kit and 3 hold the exhaust steady just fine. But if you want all 4 you'll pay an extra $15 on top of the $45 kit.

My only complaint to date with Cobb. I have all their stuff on my car, including CBE, but the hanger thing annoys me.

 

[CanadianGuy]

Well, the car has 4 hangers. The Cobb hanger kit has 3. I will never understand why Cobb shorts one on their kit, nor do they have a logical explanation (I've asked more than once). That being said, I have the Cobb kit and 3 hold the exhaust steady just fine. But if you want all 4 you'll pay an extra $15 on top of the $45 kit.

My only complaint to date with Cobb. I have all their stuff on my car, including CBE, but the hanger thing annoys me.

Get the focus ST kit for the extra 1 hanger

 

[DP03]

Get the focus ST kit for the extra 1 hanger

Yup, learned that one too late.

 

[Maxpowa]

Kind of a funny story, but my MTCBE droned because I had defective cabin pressure equalizer vents behind the rear bumper. They would flutter and flap open from the increased sound of the exhaust. I replaced both of them and the sound lessened somewhat. I also removed a lot of the junk I had stored in the spare-tire area of the trunk that might contribute to any vibrations or resonance, and this also helped.

 

[Clint Beastwood]

I made a thread about troubleshooting and eliminating drone, might help for yours