Location issue for resonators

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Duster360LA

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I have a significant drone between 1900 and about 2200 RPM, which happens to be highway cruising speed for my Duster. I bought a pair of bullet-style resonators in an effort to reduce/eliminate the drone, but am challenged by where they will fit without significantly reducing my ground clearance. The only real place where there is space is about 18 -20 inches after the collectors on my shorty header (which would be ahead of the H pipe). Will they still be effective there?
Running a 5.9 magnum, TTI shorties, 2.5 inch exhaust and Dynomax Super Turbos.

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Nope. "Wherever" a muffler or resonator is, is where any noise is they produce. So if it's right under the front seat, that's where any noise will be. The proper place for a resonator is after the muffler in the tail pipes just like @Professor Fate described.
 
I've heard both before and after the muffler from some technical sources. After the muffler may be even more challenging since the tailpipes are only an inch away from my gas tank. Time to get creative, I guess.
 
I can tell you on a customers truck at work with an aftermarket muffler that resonated badly only under load at cruising speed a glasspack before the muffler cured it.

With the super turbo mufflers on my 01 Mustang GT it drones horrible at cruise. I put glasspacks in the tail pipes and......it still drones horribly.

I would not be afraid to try it (especially if that is where you have the most room) before the muffler. In fact on a couple of vehicles I own I will be doing the same when the time comes to change exhaust.
 
I’ve had good experiences with putting resonators on after the axle.
But exhaust system noise can be a funky problem, I’ve had one project car that I first put turbo mufflers with turn downs ahead of the axle, later on I made tail pipes that came out after the axle and then I had a drone.
 
On E-bodies the resonators were under the car and the mufflers were at the back. never saw any muffler style resonators on and a-body or b-body except chrome tips and they do improve the sound. My 1966 GTO had round resonators at the back with turn downs built on them.
 
How about 1/4 or 1/8 wave resonators to fit the space you have between the collectors and mufflers? Using a 1.5" 180 mandrel bend cut in half (for two J bends) and straight header pipe to cap at the ends. Add support to it with clamps to the main pipe or a gusset near the end and middle. A 1/4 wave res designed for that low an rpm would be extremely long. They were also called "interference" pipes in the 60s.
 
These are the smallest diameter resonators I have found if you're worried about ground clearance. I too have the 1900-2200 RPM drone.

Resonators - TR?

Another option is a Helmholtz or quarter wave resonator. These are custom made chambers or tubes that tune out the frequency that the drone occurs. Many members here have built them with success.
 
Just like the factory positions, I installed resonators ahead of the mufflers on my cuda. I used straight-thru MagnaFlow units. Very little restriction, and super quiet with the
4 units installed.
On my WO car, we put 3 1/2" bullets/resonators at the kick-up, over the axle, to 3" pipe and mufflers at the rear bumper, with turn-downs.

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