Exhaust drone elimination

[Nad_Yvalhosert]

1995 Chevy 2500 chassis cab that had a service body when I bought it. Yanked it and put on a flatbed, tool box, dual spare tires, the whole Baja look.
The original muffler is long gone, due to New Yuck salty winters, and its replacement was in the same condition when I bought the truck. I wanted to free up some back pressure and give her a good rumble, so a pair of stainless single chamber mufflers were installed, and a single tailpipe all the way out back.
I've got the exact same ones on my Yukon and the exhaust note (out of the OE tailpipe) is great on the SUV, but the truck has a loud drone.
Maybe it's the difference from flatbed to enclosed interior or maybe sound deadening material... I dont know.

So what're my options?
Resonator? Where to put it?
Before the muffler or after?

 

[Frank Enstein]

Glasspack muffler (resonator) the biggest one you can fit as far back as you can put it.

Paint the system with high heat paint after you have driven it an hour straight.

You have to get it hot enough to burn the anti-rust oil off it. Wipe it down with solvent and follow the directions on the can.

If you paint it right away the exhaust will last years longer.

I like https://www.summitracing.com/parts/vht-sp106.

 

[Frank Enstein]

What size is the pipe and how much room do you have. I can try to look some up for you.

 

[Nad_Yvalhosert]

Single 3" front to back, no obstructions.
No bed, only a flat deck above the frame. I routed the exhaust as high as I could over the axle with a straight pipe, then angled it out 45° past the rear shackle.
If it had a bed on it, it would exit through the sheet metal about 8" from the bottom.
I've used all unbent stainless pipes, stainless band clamps too. That way it all can be unbolted in the future.

 

[Nad_Yvalhosert]

Glasspack muffler (resonator) the biggest one you can fit as far back as you can put it.

Paint the system with high heat paint after you have driven it an hour straight.

You have to get it hot enough to burn the anti-rust oil off it. Wipe it down with solvent and follow the directions on the can.

If you paint it right away the exhaust will last years longer.

I like https://www.summitracing.com/parts/vht-sp106.

Dont glasspacks give a spitting crackle sound under load? Really dont want that reverberating under load from a certain 30' Sunny Brook travel trailer I might tow.

 

[Nad_Yvalhosert]

Much as I hate to admit it, I was on another site... (gasp! I know, I've been disloyal) the consensus is that straight pipes enhance sonic resonance. The reverse being: curved pipes, (over the axle, around to a 90° side exit, quell said resonance.
Dang, I reduced back pressure and created a feedback in the metal pipe, kinda like a trumpet. That's why my Denali, and its OE oval tailpipe tip, sounds so good.

 

[Supercharged111]

Have you looked into a Helmholtz resonator I think it's called?

 

[Nad_Yvalhosert]

Have you looked into a Helmholtz resonator I think it's called?

Wow... how on earth would I even graft something like that on there?
Reminds me of the proboscis silencer box on the Vortec air intake tube and ducts... The one above and behind the actual throttle body inlet.

 

[Nad_Yvalhosert]

All right, here's my potential solution:

Upower 3 Inch Inlet/Outlet Exhaust Muffler, 3" Inlet Resonator with 18" Length Overall Length 22" Resonator Great Tone Universal Stainless Steel Muffler Resonator

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[thegawd]

Well that's a new concept that I have not heard of before Supercharged. interesting.