Diesel engine: above transmission acoustic mat replacement

[Gnarlodious]

https://www.thesamba.com/vw/forum/viewtopic.php?p=10253946
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Vanagon ’83 diesel AAZ w/Giles injection, 5spd 4.57R&P+TBD and a '78 diesel Rabbit

[charleslabri]

following up here, just spoke to CascadeAudio, nice folks. Based out in Louisiana.
price for the 37x54 is $149

[valvecovergasket]

I removed all of that stuff in the course of my TDI swap... And with a proper muffler mounting setup isolating the exhaust from the chassis, and an air box channeling the intake noise into the rear vent and out of the engine bay, I think a majority of the diesel clatter is imperceptible from inside the van. You can still hear it quite well outside especially near the back and next to the drivers side vent, but moving down the road it's mostly gone.

Your mileage may vary, but I don't regret not applying anything to replace that nasty stock stuff

[coclimber]

Hi all! I have horizontal metal straps & vertical piping holding my OEM junk foam to the engine bay. Is everyone removing those before starting? Seems like sliding closed cell foam under the existing would be fine too. Thoughts?
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'83.5 Westfalia Camper - SOLD
'86 Westfalia Weekender
2001 Subaru Legacy 2.5L donor
Rocky Mountain Westy kit

[vwwestyman]

[vwwestyman]

Followed a rabbit hole of links and ran across this:

http://cascadeaudio.com/marine/vb_tsm_compostie_material.htm

Looks very very similar to the originally posted product.
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Dave Cook

President, Wild Westerner Club

1978 Champagne Edition Westy, repowered to '97 Jetta TDI
1973 Wild Westerner
My Thing

[Gnarlodious]

My muffler mounting is rudimentary. The upstream mount:

The downstream mount is more robust since it shook apart after a while:

I circled an angle profile behind that stabilizes it. Notice that I use the original diesel muffler rubber absorber.
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Vanagon ’83 diesel AAZ w/Giles injection, 5spd 4.57R&P+TBD and a '78 diesel Rabbit

[AndyBees]

VW Westyman,

Below is the only pic I have uploaded of my exhaust. You can see the spring loaded donut joint to a resonator to the right (ALH TDI engine). After the resonator it curves 90 and up by 18 degrees then down by 18 degrees and then straight across to the right rear of the Van. After that second 18 degree bend, it goes through the CAT and then immediately through a glass pack to the very short exit pipe.

I have it supported in two spots to the body using rubber to absorb the vibes. It works really good. By design, I can raise or lower the exhaust system considerably with it flexing at the donut joint. What I have noticed is when I raise the end (exit) up to or near the highest point, the noise is much louder inside... same with lowering it to the lowest point. Thus, I finally found the best level. And, I suspect the different positions add or take away stress from one hanger to the other affecting vibes, etc. It is mostly 2" SS and I used SS bands for joints. So, I can have the exhaust system completely off the Van/Engine in a matter of minutes.

EDIT: As others have stated/indicated, drone from the exhaust and intake are the primary noise culprits for the tin can. I pretty much addressed the noise issues as suggested in this thread. Of course, I never used the same materials (likely mine are inferior comparatively speaking). But, I used a two layer approach. Also, you'll be surprised at how much of a positive affect will be enjoyed by adding a barrier on the back of the kick-board of the back seat.

The pics below show the two layers as they were being installed on the back wall under the back seat and around the fabricated raised deck lid as well as the outer paneling.

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'84 Vanagon Tin-top, ALH TDI, two trips to Alaska, 2014 & 16. 1989 Tin-top unmolested.
1983 Air-cool, 225k miles, 180k miles mine, seven trips to Alaska from 1986 thru 2003. 1975 Bay hopeful.

[vwwestyman]

[Gnarlodious]

[vwwestyman]

With more looking on the site, they do have other thicknesses available with the vinyl layer.

https://www.boatid.com/soundown/
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Dave Cook

President, Wild Westerner Club

1978 Champagne Edition Westy, repowered to '97 Jetta TDI
1973 Wild Westerner
My Thing

[vwwestyman]

[Zeitgeist 13]

My primary issues are intake drone and to a lesser degree exhaust drone. It's definitely a drone and not a vibration point source. This is a very common issue when customizing intakes/exhausts since the manufacturers spend a lot of time tuning out the drones and rasps, and I just threw out all that R&D with my one-off install. I'd like to include the acoustic mat, but will have to wait until I can afford it. For now, I'm trying to tune the drones.
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Casey--

'89 Bluestar ALH
'01 Weekender --> full camper
NEAT, no ICE.

[?Waldo?]

You will get better engine vibration isolation mounting the exhaust only to the engine.

[vwwestyman]

[Gnarlodious]

How is your exhaust pipe mounted? I found that low drone pretty serious after an exhaust shop hung the tailpipe from the frame. Apparently vibration was propagating all through the body. I had it rehung from the engine and it was a lot better.
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Vanagon ’83 diesel AAZ w/Giles injection, 5spd 4.57R&P+TBD and a '78 diesel Rabbit

[Zeitgeist 13]

Agreed, but I'm trying to isolate the frequency. My calculations led to 50Hz, which will be my target for attenuation...to begin the process. There are other frequencies to target at other RPMS
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Casey--

'89 Bluestar ALH
'01 Weekender --> full camper
NEAT, no ICE.

[Gnarlodious]

Yeah but its a lot louder.
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Vanagon ’83 diesel AAZ w/Giles injection, 5spd 4.57R&P+TBD and a '78 diesel Rabbit

[Zeitgeist 13]

Since this is a diesel sound mitigation thread, I thought I'd ask folks if this is the drone sound you most likely hear at around 3k to 3.6k in your vans:


Link

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Casey--

'89 Bluestar ALH
'01 Weekender --> full camper
NEAT, no ICE.

[Zeitgeist 13]

That link is for a 2" thick sheet.

Here's a larger sheet of 1" foam for cheaper:

https://www.boatersplus.com/soundown-iaf10mnsft36....XcEALw_wcB
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Casey--

'89 Bluestar ALH
'01 Weekender --> full camper
NEAT, no ICE.