HelmHoltz resonator - No more drone !

[Yukon Joe]

Easy fix for sure.

I'll make that appointment first thing tomorrow!

Delta Lead
Yukon Joe

www.runraptorrun.com

 

[F150Feste]

So I did the research and measured and designed an adjustable J-tube (helmholtz) resonator onto my Roush exhaust the other day and it performed exactly as planned. The problem was finding anyone in the DFW area that had mandrel bent tubing, was lucky to find Kinney's Muffler in Watauga (great shop by the way, very clean/professional and good pricing). I took two different designs that I liked and put them into one, to make a 3" tube that was 26" long and then flared it to accept to the capped piece that could be shortened to 26.5" total length or 31" total extension and made the cap that way to have something to grab to pull out or push in vs being flush - and still allow the clamp to hold it. I started off at 28" length and it was perfect. Still have the loud grumble of the Roush exhaust and at most RPM ranges, absolutely no in cabin drone/harmonics to interfere with stereo/phone or conversations any longer. 100% pleased and still shocked that no muffler shops even know what these things are or how they work, seems that this could remedy a lot of unhappy customers with exhausts that are put on that have too much drone and make a few extra bucks in the process.

 

[Yukon Joe]

So I did the research and measured and designed an adjustable J-tube (helmholtz) resonator onto my Roush exhaust the other day and it performed exactly as planned. The problem was finding anyone in the DFW area that had mandrel bent tubing, was lucky to find Kinney's Muffler in Watauga (great shop by the way, very clean/professional and good pricing). I took two different designs that I liked and put them into one, to make a 3" tube that was 26" long and then flared it to accept to the capped piece that could be shortened to 26.5" total length or 31" total extension and made the cap that way to have something to grab to pull out or push in vs being flush - and still allow the clamp to hold it. I started off at 28" length and it was perfect. Still have the loud grumble of the Roush exhaust and at most RPM ranges, absolutely no in cabin drone/harmonics to interfere with stereo/phone or conversations any longer. 100% pleased and still shocked that no muffler shops even know what these things are or how they work, seems that this could remedy a lot of unhappy customers with exhausts that are put on that have too much drone and make a few extra bucks in the process.

Nice design.
I like the cap idea.

What material did they use?

I wanted stainless, instead I ended up with carbon pipes welded to my stainless exhaust. [emoji53]

@Yukon Joe
Drive your raptor here!!!!
www.runraptorrun.com
( * Y * )

Post a pic ofyour Raptor here:
https://r.tapatalk.com/shareLink?ur...&share_tid=49261&share_fid=17668&share_type=t
Calendar contest August 17
♤♤♤♤♤♤♤♤♤♤♤♤♤♤♤♤♤♤♤♤

Vote for a pic here: vvvvvvvvvvvv
http://www.fordraptorforum.com/showthread.php?p=1010757

 

[F150Feste]

Thanks.

They used same 409 stainless that the Roush pipes were made of, so it will rust over on outside just like the mid-pipe it's attached to, and blend in but shouldn't rust through for a long time.

 

[t_j]

So I did the research and measured and designed an adjustable J-tube (helmholtz) resonator onto my Roush exhaust the other day and it performed exactly as planned. The problem was finding anyone in the DFW area that had mandrel bent tubing, was lucky to find Kinney's Muffler in Watauga (great shop by the way, very clean/professional and good pricing). I took two different designs that I liked and put them into one, to make a 3" tube that was 26" long and then flared it to accept to the capped piece that could be shortened to 26.5" total length or 31" total extension and made the cap that way to have something to grab to pull out or push in vs being flush - and still allow the clamp to hold it. I started off at 28" length and it was perfect. Still have the loud grumble of the Roush exhaust and at most RPM ranges, absolutely no in cabin drone/harmonics to interfere with stereo/phone or conversations any longer. 100% pleased and still shocked that no muffler shops even know what these things are or how they work, seems that this could remedy a lot of unhappy customers with exhausts that are put on that have too much drone and make a few extra bucks in the process.

Looks great, welds are well questionable (Lack of penetration on the cap at one point and only some tacks between the bend of the main tube and the adjustable section)! Probably want to have a support welded in between the outer tube and the main exhaust tube if you are doing any serious off roading. Get a hole saw and cut into that cap, pick up another one and bolt it on, that way you can have a cutout if you want to be a little extra loud some days.

 

[F150Feste]

Thanks, I hadn't noticed the tack only on the main to bend tube. The rear cap I'm not worried about but will have them take a look at it next time out that way. I can fab up support and use one of the bolt holes in cap if it needs it, but it's stoutly held on there despite the appearance that's it's not.

**update, that tack was only until they adjusted the pipe, it was fully welded. My pic was before it was completed.

 

[SHAI HULUD]

So I did the research and measured and designed an adjustable J-tube (helmholtz) resonator onto my Roush exhaust the other day and it performed exactly as planned. The problem was finding anyone in the DFW area that had mandrel bent tubing, was lucky to find Kinney's Muffler in Watauga (great shop by the way, very clean/professional and good pricing). I took two different designs that I liked and put them into one, to make a 3" tube that was 26" long and then flared it to accept to the capped piece that could be shortened to 26.5" total length or 31" total extension and made the cap that way to have something to grab to pull out or push in vs being flush - and still allow the clamp to hold it. I started off at 28" length and it was perfect. Still have the loud grumble of the Roush exhaust and at most RPM ranges, absolutely no in cabin drone/harmonics to interfere with stereo/phone or conversations any longer. 100% pleased and still shocked that no muffler shops even know what these things are or how they work, seems that this could remedy a lot of unhappy customers with exhausts that are put on that have too much drone and make a few extra bucks in the process.

I need this for my SW lightning!!! Well done!

Sent from my SM-G930V using Tapatalk

 

[RV-Junke]

Hey guys, I've been off the site for almost a year. It is awesome, all of you have tweaked the solution, congratulations. It is amazing how it killed the noise. Thanks for keeping this going. It went unnoticed for almost a year. Fred.

 

[Otis857]

So I did the research and measured and designed an adjustable J-tube (helmholtz) resonator onto my Roush exhaust the other day and it performed exactly as planned. ...
I started off at 28" length and it was perfect. Still have the loud grumble of the Roush exhaust and at most RPM ranges, absolutely no in cabin drone/harmonics to interfere with stereo/phone or conversations any longer. 100% pleased and still shocked that no muffler shops even know what these things are or how they work, seems that this could remedy a lot of unhappy customers with exhausts that are put on that have too much drone and make a few extra bucks in the process.

A while back, I asked a local muffler shop about the Hemholz resonator and got a similar response. They essentially said, get me specs and I cam make it.

Question; did you experiment with other lengths since you made it adjustable? If so, any difference or did you stay with the 28" length? I dont suppose it would matter, but do you suspect any tuning/drone difference with this length for us normally aspirated Raptor guys?

 

[RV-Junke]

I did not check lengths. I actually downloaded a bunch of wave files for the radio that allowed me to dial in the length based on the wave that was most canceled. I do not think it is an exact science that covers every situation. For example when it is 40 deg I get a VERY slight drone at 50mph, so I am assuming the length covers most variables.

A while back, I asked a local muffler shop about the Hemholz resonator and got a similar response. They essentially said, get me specs and I cam make it.

Question; did you experiment with other lengths since you made it adjustable? If so, any difference or did you stay with the 28" length? I dont suppose it would matter, but do you suspect any tuning/drone difference with this length for us normally aspirated Raptor guys?