Diesel engine: above transmission acoustic mat replacement

[AndyBees]

I picked up bits here and there for my fabrication.

I used the pipe going down the back of the engine to the Turbo from the donor engine. I cut it into useable pieces. One piece to connect to the turbo which was connected to a small accordion pipe I found in a junk yard.

The accordion piece is connected to a rubber 90 degree silicone pipe that points straight cross the back of the engine bay toward the front side of the right tail light. It goes just at the top of the license plate hole. At that point, it is connected to the upper bit I cut off the donor pipe then is connected to the OE pipe that normally goes to the Jetta air box/MAF. The MAF is connected to my fabricated air filter tube.

Hopefully the photos in this link will be helpful to understand what I did.

http://pics.tdiclub.com/showgallery.php?cat=5268&page=1
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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.

[tkic]

Thanks for the data on this, It inspired me to order some acoustic foam and get cracking.

[iliketowalk]

[tkic]

[vwwestyman]

Well the product in the original post is NLA, at least from the linked seller! Just called and tried to order but he said it was kind of a side thing for their company and when the manufacturer went out of business or change distribution or something, they didn't bother to find a replacement.

He suggested that there may be similar materials either from McMaster Carr or Grainger.

Back to the drawing board.
_________________
Dave Cook

President, Wild Westerner Club

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

[joetiger]

Googled "Soundown Acoustic Foam."

Is this the same stuff?

https://www.boatid.com/soundown/32-x-54-x-1-vinyl-...eiEALw_wcB
_________________
Joe T.

'86 NAHT Vanagon GL Syncro/ supercharged ABA 2.0 "Pigpen"
'91 Wolfsburg Carat "Barchetta"
'02 Baja-ish Beetle "Bubbles"

"get metaphysical with it. if it's simply a means to get to and from places, it will let you down. if it becomes your zen, it can't fail you." -dabaron

"Still, it's good to be afield."--VWagabond

Justice for Megan: https://linktr.ee/justiceformegantrussell

[Gnarlodious]

Looking at the spec sheet and it does appear to be the same stuff:
https://www.boatid.com/images/soundown/items/pdf/vinyl-foam-technical-specifications.pdf

May as well add that I have been using this stuff for 4 years now and am very impressed with its durability. I have pressure washed it several times and the surface has not ripped or damaged, and the aluminum tape is holding good.
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Vanagon ’83 diesel AAZ w/Giles injection, 5spd 4.57R&P+TBD and a '78 diesel Rabbit

[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.

[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

_________________
Casey--

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

[Gnarlodious]

Yeah but its a lot louder.
_________________
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]

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

[vwwestyman]

[?Waldo?]

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

[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.
_________________
Casey--

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

[vwwestyman]

[vwwestyman]

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

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

President, Wild Westerner Club

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

[Gnarlodious]

[vwwestyman]

[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.

_________________
'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.