2004 6.0 NV4500 Tahoe

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Sam Harris

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Its 1" per 100rpm right? so 2,000rpm drone you want a 20" pipe? does it matter the diameter or the pipe?
There’s a little more to it than that. I don’t remember off hand how it was calculated, but it’s pretty simple. Here’s a video of a guy explaining it. Haven’t watched this yet, but seems good from the start anyway. https://duckduckgo.com/?q=how+to+ma...i=https://www.youtube.com/watch?v=z5SY5oUTEcc
After my work meetings I’ll watch. [emoji16][emoji106]
 
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Dantheman1540

Dantheman1540

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There’s a little more to it than that. I don’t remember off hand how it was calculated, but it’s pretty simple. Here’s a video of a guy explaining it. Haven’t watched this yet, but seems good from the start anyway. https://duckduckgo.com/?q=how+to+make+a+helmholtz+resonator&t=iphone&iax=videos&ia=videos&iai=https://www.youtube.com/watch?v=z5SY5oUTEcc
After my work meetings I’ll watch. [emoji16][emoji106]

Interesting character there but good info. I found this thread on it I remember reading some years ago. I think I will everything I can to get the clearance needed for the exhaust and get as many of the resonators that I already have in there. Then if it's still droning I will do a J tube.
I could probably do the J tube myself with a kit of 2" tubing bends.

https://www.performancetrucks.net/f...-resonator-tube-eliminate-drone-489463/page6/
 

iamdub

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I might finally try that, whats kept me from doing one from the start is that they only target a specific rpm right? For example, If I built one to cut out drone at 2,100rpm while on the highway in 5th at 75mph it wouldn't do much if I'm towing and keep it in 4th and 2,650 at 75mph right?

It targets a specific sound frequency. You use the RPM that the offending noise happens at as an earmark and run the calcs to determine what frequency it is then build the tube accordingly. If you had a way of knowing the frequency of the offending sound regardless of the RPM, then you could skip a lot of the math and build a tube 1/4 the length of that sound wave.

It targets the center frequency, but there is a rolloff of the surrounding frequencies that are also attenuated. I don't know the rate (slope), but it's not just that one specific frequency and that one only.
 

Sam Harris

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Dantheman1540

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It targets a specific sound frequency. You use the RPM that the offending noise happens at as an earmark and run the calcs to determine what frequency it is then build the tube accordingly. If you had a way of knowing the frequency of the offending sound regardless of the RPM, then you could skip a lot of the math and build a tube 1/4 the length of that sound wave.

It targets the center frequency, but there is a rolloff of the surrounding frequencies that are also attenuated. I don't know the rate (slope), but it's not just that one specific frequency and that one only.

When the time comes I'll probably do one off the 4" single tail pipe kinda where the spare tire used to go. I think it could be tucked up there nicely.

Man, Mr. Lahey is gonna be so mad...!

(RIP Mr. Lahey)

There was a maintenance dude pacing back and forth in his golf cart.

R.I.P. Mr. Lahey



Gave the clutch a good workout today dragging the last couple of oak logs into position around my planter. I'm not sure how heavy these are but it takes some serious whoopow to get them moving. The last one really gave me a fight because the position of the back tires was sand and dry leaves, a recipe for no traction. The 420s did their best but it ended up taking multiple clutch dumps and laying a path of boards and pavers to get it out. G80 is truly a champ in these situations, locks right up and starts digging.
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Tonyrodz

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