1/4 Wave Resonator- Drone Fix- 2020 6.2L Muffler Delete

Terry Wood · November 3, 2020

Has anyone with a 2019 or newer 6.2L Sierra/Silverado successfully built a 1/4 Wave Resonator/J-Pipe to eliminate drone after a muffler delete? I am in the process of planning and trying to see which length will work best. My drone is the heaviest around 1500 RPM which is high 70's on the highway. It's not bad now but I know if I ever tow, it will be annoying.

Also, if anyone knows a good welder that would be willing to build one and ship it to me, I'd love their contact. I'm in a small area in Oklahoma and when I say "1/4 wave resonator or helmholtz resonator", I get some pretty odd looks. I'm looking to get a 3.5in "T" so I can install the resonator at home.

I have attached a rough drawing of what I'm looking for.

redwngr · November 3, 2020

No need to use the terminology with the fabricator.

Enough to just say you want to tune the sound.

Many years since I did any exhaust system design for sound level attenuation.

Are you planning to experiment with diameters as well?

Interested to see the posts about how it works out!

Terry Wood · November 3, 2020

53 minutes ago, redwngr said:

No need to use the terminology with the fabricator.

Enough to just say you want to tune the sound.

Many years since I did any exhaust system design for sound level attenuation.

Are you planning to experiment with diameters as well?

Interested to see the posts about how it works out!

I'm planning to be one-and-done. If I had a welder then maybe a different story. From what I've read, the diameter doesn't change the frequency being targeted but just allows for more attenuation which is why I'm trying to match the diameter of the existing exhaust for max attenuation.

Edited November 3, 2020 by Terry Wood

Sqrls · November 3, 2020

Ford and BMW (maybe others as well) use ballast weights or variations of the concept on the exhaust to help even out the sound. Might be an easier alternative to consider for the same result.

Terry Wood · November 4, 2020

8 hours ago, Sqrls said:

Ford and BMW (maybe others as well) use ballast weights or variations of the concept on the exhaust to help even out the sound. Might be an easier alternative to consider for the same result.

Thanks. I have two clamps coming, just need to figure out what to use as test weights and then where to buy more if it works. Also, trying to figure out how much weight would actually be needed.

I have decided to add a Borla XR-1 muffler to the equation which should be installed Friday. I wont make any other changes until that is complete. I hear Borla is very good with eliminating drone as they tune mufflers so I hope I have success with this. Or at least some positive change.