Drone issues with the following setup …

[singingwhodat]

Originally had just the Gibson Catback and had zero drone. Currently have the SPD Downpipes, Lethal MidPipes and Gibson Catback When I first installed this setup everything sounded great. I am now experiencing drone from 1500 to 2000 rpm’s and it is progressively getting worst.

I brought it to an exhaust shop thinking it was rattling but it wasn’t. Now the drone is just obnoxious. What would cause the drone to get louder over time? Please share any experience with this issue and any suggestions on how to get rid of it.


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[mycbtech]

Heat expansion and contraction within the baffles of the cat back causing them to change resonance. Also could be from a connection that is causing the exhaust to press against a body panel when expansion is happening due to heat creating a resonance that is proceived as drone.

 

[UNBROKEN]

If you’re positive it’s not the system getting hot and growing to the point it’s touching something and causing a resonance issue that could be fixed by adjusting the system for more clearance…you could have had a muffler spit out the packing or come apart internally causing the drone. If everything is good on both those fronts maybe the mufflers just burned in and now it drones…in which case a pair of Helmholtz (j-pipe) resonators will cure it 100%.

 

[GearHead_1]

If you’re positive it’s not the system getting hot and growing to the point it’s touching something and causing a resonance issue that could be fixed by adjusting the system for more clearance…you could have had a muffler spit out the packing or come apart internally causing the drone. If everything is good on both those fronts maybe the mufflers just burned in and now it drones…in which case a pair of Helmholtz (j-pipe) resonators will cure it 100%.

I'd have said the same but couldn't have said it better. A muffler "burning out" is about the only thing I can think of that would make things progressively worse.

 

[singingwhodat]

If you’re positive it’s not the system getting hot and growing to the point it’s touching something and causing a resonance issue that could be fixed by adjusting the system for more clearance…you could have had a muffler spit out the packing or come apart internally causing the drone. If everything is good on both those fronts maybe the mufflers just burned in and now it drones…in which case a pair of Helmholtz (j-pipe) resonators will cure it 100%.

I thought the same on the system getting hot but now it starts droning as soon as I start up and take off. I will have to check the mufflers and also check the alignment one more time. Any recommendations on where to get the J-Pipes?


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[TMac]

Unless the packing is slowly but progressively blowing out, it just doesn't seem feasible that "it is progressively getting worst." Once you start to notice something like a drone, you can't unhear it- and it might seem that it's getting worse. I'd see f you have some internal break.

Get underneath at idle and listen. An easy "stethoscope" can be made with a bit of tubing and a bolt. Find a length of 3/8" hose that you can fit one end in your ear. In the other end, thread in a bolt or a punch or something metal that fits tightly. Put the metal piece on the muffler or connection and see if you hear a tell-tale buzzing.

 

[Cdubya]

I'd check for an exhaust leak. My Gibson seemed to progressively get more drone but I found the stock flex section had failed. Since you don't have that problem, make sure all the exhaust connections are tight and haven't worked their way loose.

 

[singingwhodat]

Well it looks like I do have some leaking Any suggestions? Weld?






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[Cdubya]

Those clamps need to be super tight. I used a breaker bar because the car was not jacked up...otherwise I'd use an impact wrench.

 

[UNBROKEN]

Tighten the clamps again but condensation/soot seeping out is fairly normal.

 

[singingwhodat]

Those clamps need to be super tight. I used a breaker bar because the car was not jacked up...otherwise I'd use an impact wrench.

Any recommendation on torque? Don’t want to smash the pipe lol


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[Cdubya]

the OE exhaust that you are mating your midpipe to have slots in them (or at least my early MY2020 does). make sure the midpipes are inserted far enough past those slots.

 

[UNBROKEN]

Any recommendation on torque? Don’t want to smash the pipe lol


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That style of clamp won’t smash the pipe. The bolt will break well before that.

 

[singingwhodat]

I’m about to toss the Gibson Exhaust. I hear something rattling inside of one of the mufflers and the drone is louder so I’m pretty sure it’s coming from there!


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[Dale5403]

I’m about to toss the Gibson Exhaust. I hear something rattling inside of one of the mufflers and the drone is louder so I’m pretty sure it’s coming from there!


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If your the original purchaser of the Gibson exhaust they have a lifetime warranty. Might be worth checking.
https://gibsonperformance.com/ft-2073-lifetime-limited-warranty.html

 

[singingwhodat]

If your the original purchaser of the Gibson exhaust they have a lifetime warranty. Might be worth checking.
https://gibsonperformance.com/ft-2073-lifetime-limited-warranty.html

I appreciate the heads up. I am the original owner. I will reach out to them


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