Exhaust question (drone elimination)

[DZLROKET]

OK so I dumped the factory muff. on my 06 2500 SWB 4X4



Bought a straight through Summit racing 40"X6" muffler.

( Louver openings facing the motor)



I like the sound but now I have a drone in the cab under load.



Short of buying a different muffler, would some sort of resonator or small straight thru muffler cure this condition and still give me the benifits I got?



IE: faster spool up, lower EGT's, slightly more HP



Thanks for your suggestions

 

[nickleinonen]

how about just trying to reverse the muffler direction?

 

[DZLROKET]

It's already installed in the "quiet" direction

 

[mberry]

I thought the cat also functioned as a resonator to eliminate drone.

 

[opjohnny]

I think some people have had luck with a bed liner or dynamat in the cab. Changing the position of the muffler also helps. I think the back of the cab and front of the bed are trouble spots the metal is thin and the sound frequency change is enough to cause the problem. The natural frequency of the exhaust is to close to one on the truck somewere. That causes the drone.

 

[nickleinonen]

It's already installed in the "quiet" direction

that may be, but if installed reverse, it might change the way it resonates to kill the drone. if it isn't too much work, try it and see if it kills the drone. if it works, it won't cost much eh? [hour of time maybe???]

 

[EMD-Run8]

I found on my '04 that when the muffler is mounted as far forward as possible, that there was practically no drone. A muffler like an Aeroturbine is small and will mount right behind the downpipe. Sounds excellent.

 

[AHunter]

my 97 3/4 ton ctd has a 5 inch exhaust with muffler and drones but only when the engine and the exhaust frequency is close.

 

[Greenleaf]

I installed a Nelson Resonator. 4" in/out. Straight through. It's only 16 " long and thought it wouldn't do much but it sure has. No drone. I have shorty stacks w/miter cut. Still pretty mouthy, w/out drone, even applying throttle up hill.

 

[steved]

I installed a Nelson Resonator. 4" in/out. Straight through. It's only 16 " long and thought it wouldn't do much but it sure has. No drone. I have shorty stacks w/miter cut. Still pretty mouthy, w/out drone, even applying throttle up hill.

Do you have a part number by chance?? I need to take the edge off my exhaust... short of buying a full 51" donaldson...



steved

 

[CStraface]

I am currently running just a cat and no muff. I am cutting out the kitty today, and putting in a 30" muff. I am going to put it as far forward as possible just for ease of installation.

 

[Greenleaf]

Fleetguard/Nelson Resonator



4" pipe/ Body dia. 9. 00inch/Body length 11. 50inch/Overall length 16. 2inch



Part Number 86144M



I install them onto the bus fleet as well. Replacing the 51 inch long straight through muffler. It's loud and the driver say so, but I like the sound of it.



BTW, $55. 00 at my truck dealership.

 

[DZLROKET]

bought one from cummins /fleetguard but had to pay $72, will report results. installing between cat and muffler

 

[Greenleaf]

bought one from cummins /fleetguard but had to pay $72,

Sorry. I often forget that I price parts at the government discount. Out side of toilet seats and the occassional hammer handle, I recieve a break on parts.