Cool, that answers my question! Thanks for your feedback on both posts KB

 

I no longer have a GM truck, but I do have a Grand sport LS3 Vette that I'm currently researching how to eliminate the drone, maybe you all can help.

If I read the original post correctly, the resonator pipe is supposed to be installed after the muffler/s. The vette has an axle back system, where mufflers are after the rear axle. No room for a resonator after muffler.

Is there a way to still make this system work with a resonator pipe of some sort either in line installed in mid-pipe or installed somewhere before the axle back mufflers?

My Vette is an LS3 with LS7 manifolds, LS7 cat-deleted cat-pipes, 3 inch x-pipe and a 3 inch Akrapovic dual mode axle back. It drones around 1500-1800 rpm. An ear piercing drone. Even with the dual mode exhaust closed.

Thanks for your help!

 

Perhaps you can weasel a loop like this around the muffler.

 

here's what i had done a local muffler shop and it elimated drone and i have a blower and headers. it is welded in-between the my magna flow resonator and corsa sport muffler

 

The length of the resonator tube can be any multiple of the frequency length. The example just so happened to be 1/4.

Thanks,
Jim Parker

 

It can be, however the more times a standing wave travels through a medium without active forcing, the weaker it becomes. For example the manufacturers these days often explicitly calibrate for several harmonics specific to intake runner size and geometry. The strongest pressure reinforcement at the intake valve is always due to the wave that has traveled back up the runner the fewest number of times.

 

I did this on my '06 Denali. 6.0 with magnaflow dual inlet dual outlet muffler. Stayed with the outlet y pipe with 3 inch tail pipe and the drone was terrible. Kids were having a hard time hearing when on long trips. Changed the tailpipe to a 3.5 inch HD style tail and added the resonator tube, approximately 32 inches and 2.5 inch diameter. It is night and day difference. It is almost quieter than stock now, until you WOT. Then you know something is up. Great mod! Thank you all for the thread.

 

Again digging up an old thread... but how does adding a 90* bend change the length required to work properly? Anyone have the math on that?

 

Calculating pressure deltas due to tortuous flow is sort of black magic in the mechanics world lol. The biggest impact it will have is reducing the effectiveness of the resonator. It will likely end up requiring a slightly shorter tube, but it could be on the order of a millimeter or less...not really a big impact. I'd probably just do what Kyle did and make it adjustable with an exhaust clamp.

 

Built one of these today. 24" long. Hopefully it helps. Otherwise I'll be removing the spare (wrong size anyways) and extending it with some flex pipe.