Date:         Wed, 17 Jul 2013 20:21:43 -0700
Reply-To:     Tom Boldway <jboldway@HOTMAIL.COM>
Sender:       Vanagon Mailing List <vanagon@gerry.vanagon.com>
From:         Tom Boldway <jboldway@HOTMAIL.COM>
Subject:      Sound proofing, was: Muffler question
Content-Type: text/plain; charset="iso-8859-1"

I have used a multitude of sound deadening methods. Unfortunately I have revisited a few areas and applied another layer of peel & seal and also glued on some cut out pieces of closed cell foam sleeping bag pads that are 1/2" thick or so. Wallyworld, like $7 for the sleeping bag pad. I have used a product called "Goop" to glue the closed cell foam on. It's a hassle as the foam wants to curl when you apply the glue so you have to maintain pressure on it for a while. My exhaust is louder than most as I went to the hardware store and got a 12" long 1/2" drill bit and drilled up through the core of the muffler to try to cut backpressure. I also modified the "Y" pipe adapter to eliminate the horrible restriction that the "Y" pipe specific to the 1.9L motor has. I need all the power I can get . . . I have an automatic 1.9L in a 1984 Westy with a lot of weight added (solar panels, two extra batteries, microwave, and other stuff). Next power upgrade will be the 1.4 ratio rocker arms. 
Automotive headliner material has been glued (using rubber cement) to the hardboard headliner in the cab area, in the rear area and on the rear hatch panel. Make sure your seals on the door and such are tight. 
The rear floor where the engine lid attaches has been covered in a double layer of Peel & Seal, and same with the doors which then got the closed cell foam treatment, even the rear hatch. I put some closed cell foam over the holes in the bottom of the rear hatch, I assume moisture will still escape but the noise won't be as bad. 
Next steps: possibly replacing the flat side mirrors with something a bit more aero and for what I assume will be another decent reduction - installing a set of Synchro plastic wheel well arches from busdepot. You're sitting right over the front wheels - all the noise is right under you!
Put the peel & seal in like two or three layers under the rug where it attaches to the wheelwell (right next to driver and passenger seat) and all over the wheel wells inside the cab 9again pull up the carpet to gain access).
The michelin Agelis were noticeably quieter than most vanagon tires, but I do not see them around anywhere. I just got Kuhmos which are not that quiet but better than what I had. 
Pictures are at http://www.pbase.com/spacecommander/westfalia_vanagon_mods
Hope this helps somebody

Tom

'79 Mercedes 300SD "Green Hornet"
'84 Westy Vanagon "Spiny Norman"
'86 Alfa Romeo Spider "Dinsdale"
'98 Mercedes E320 wagon "Silver Hornet"