Insulation Experiment

[IdahoDoug]

When I was with Lexus, we went to great lengths on soundproofing to achieve industry records for ambient noise levels in the interior. I didn't do the engineering on this but I remember studying the drawings and what they did and here's what I remember.

They found putting foam plugs in all the roof pillars was worth doing as they transmitted wind roar through essentially hollow steel tubes into the interior. A can of that expanding foam carefully used through a screw hole in each pillar might work. Just a tiny pffft as some of it expands greatly and you don't want it coming out every hole. Heh, getting a visual on that.

Also, foam plugs in the rocker panels. I'd also consider any hollow floorpan sections leading from the engine bay also for a foam plug. I'd definitely get some guidance on using a product that would not absorb moisture after it has cured, and also study the sections to be sure that VW did not design them to drain water from the body. Look for slit drains. This would be especially important to look for if you have a factory sunroof which usually has 4 drain tubes down roof pillars.

On the floor, the greatest benefit was on the firewall, the front seat floor and the rear seat floor where they used double walled sheetmetal with a visco layer between. I'd guess the only way you could duplicate that would be a layer that dampens vibrations but I couldn't guide you as to apply it on the outside or interior side but my suspicion is it does not matter for acoustics but may matter for corrosion potential with moisture (favoring the interior).

They also lined the outside of the wheel wells with a tarlike substance to absorb gravel/road debris sounds.

HTH,

DougM
_________________
1987 2WD Wolfsburg Vanagon Weekender "Mango", two fully locked 80 Series LandCruisers. 2017 Subaru Outback boxer. 1990 Audi 90 Quattro 20V with rear locking differential, 1990 burgundy parts Vanagon. 1984 Porsche 944, 1988 Toyota Supra 5 speed targa, 2002 BMW 325iX, 1982 Toyota Sunrader

[PIRATE]

two things that spectrum stuff blows!!!!!!!!!!!!!!!! and buy peel and stick!!!

I also put spectrum in my van I had it in my van for 2 years. it took me a week to install all of it because of the dry times. you need at minimum 4 coats i did 6 and I cleaned everything then used paint degrease to clean all the panels and floor before I installed it.

I put everything back together and it did a pretty good job but then i went to pull a door panel and it had started peeling i was pretty bummed. I talked to the manufacture and they said that it must have been greasy before I put it on so it was my fault. I did more prep then the instructions required and I wiped it down with degreaser.

Its to hard to install

It takes lots of time to install

One 12x12 piece of B- quite from ebay does the exact same thing for the same price and I could of been done in a day

I cant believe they say you can use it as an under coating

Dont buy!!

mas
_________________
2003 jetta wagon
1987 westfalia 2wd
1987 Syncro GL
1964 vespa vbb 150
1973 vespa sprint
2005 toyota tacoma Ole reliable

[Jamos]

If you're looking for a measurement microphone on the cheap, I would recommend this:
http://www.amazon.com/Behringer-ECM8000-Condenser-Microphone-Omni/dp/B000HT4RSA
You want a mic that has a really flat frequency response for this type of applicatoin.

Then get a USB computer interface, like this for example:
http://www.amazon.com/gp/product/B002QZ402Q/ref=pd...7Q47YDS2NZ

and the RTA software...
and then you'll see what's happening across all frequencies in live time!
_________________
'86 Wolfy Westy Weekender
2020 Audi Q5

[1621]

FWIW, I've had the Spectrum in my wheel wells for a couple years and probably 20K+ miles now - no peeling, flaking or chipping yet. Good stuff.

I really appreciate IdahoDoug's comments on this, nice to hear from someone with genuine auto design and manufacturing experience. I've always wondered what they did with the Lexus to make it so quiet.

As for sound deadening, I think there are good and better options available. I think it's important to point out that many only place the vibration dampener, often more than required, and expect to cut a lot of road noise. I too have done this, and stopped short of adding a sound barrier over the vibration dampener. If I do this again on another vehicle I'll do things a bit differently using less dampener and focus more on sound barriers. It would be nice to see someone record the differences using vibration dampener only versus a dampener and sound absorber together.
_________________
'85 Westy

[IdahoDoug]

Thanks. We were so meticulous on the Lexus models that even the different reflective acoustics of a leather interior vs cloth were taken into consideration. The audio systems that went into the cloth models had a different initial bass/mid/treble and other factors vs the leather systems. Incredible detailing. When you changed from AM to FM the power antenna shortened itself to be closer to the ideal length. And when you changed from one side of the frequency to the other, it also changed. Window tints were different for the grey vs tan interiors. They were enormously expensive to build and that's why you'll see the original generation of LS400s on the street for decades. Kinda like the pre-92 Mercedes S class beasts will too.

DougM
_________________
1987 2WD Wolfsburg Vanagon Weekender "Mango", two fully locked 80 Series LandCruisers. 2017 Subaru Outback boxer. 1990 Audi 90 Quattro 20V with rear locking differential, 1990 burgundy parts Vanagon. 1984 Porsche 944, 1988 Toyota Supra 5 speed targa, 2002 BMW 325iX, 1982 Toyota Sunrader

[EvilDNA]

Man John, I thought I had projects. I also second the Peel N Seal from Lowes or HD. Basically roofing flashing. I did my entire MV in FatMat, but ran out and finished up with Peel N Seal. I couldn't tell the difference at all. No smells and no off gassing that I could perceive.

Needless to say, HUGE difference. If the paint on stuff is better, I can't imagine it being so much so that it would negate the ease and simplicity of the Peel N Seal. Anything with paint sucks because the prep sucks and the cleanup sucks.

I'm doing a buddy's 88 Wolfsburg as we have time and it's minimal prep, really no cleanup to speak of. We'll do a roll when we have time and come back later for more. The flexibility and ease of install of the peel and stick stuff, to me, trump a few dB's.

As a note, however, don't do it in the dead of winter. I had to use a hair dryer to really get it pliable. This current install is MUCH simpler.
_________________
1990 4 Speed Orly Blue Multivan

[madspaniard]

Two things that I've read here called my attention.

Using recycled denim material and on a different post, using expandable foam in a can. I believe both of these materials retain moisture, bad if you care about rust.
_________________
1991 Westy auto w/ Peloquin TBD

"The only difference between me and a madman is that I'm not mad” - Salvador Dali

[insyncro]

[JPrato]

excellent reference site: http://www.sounddeadenershowdown.com/cgi-bin/index.cgi

mass loaded vinyl after application of dampener pads is the way to go to keep sound out of the interior. I think this material is only practical on the floor of the van but that has to be where the majority of road noise is coming from, especially around the front wheels.
_________________
Joe

87 Syncro Tin Top project
84 Westy, 2.5L Subaru power
06 Subaru 2.5 turbo in waiting
46 Cessna 140

[randywebb]

I find the 'showdown' URL to be of limited usefulness because of methodology - or lack thereof.


This thread has a bit different focus, and never really went too far (yet) but it might be helpful to some...

http://forums.pelicanparts.com/porsche-911-technic...ost4019432
_________________
1986 2.1L Westy 2wd Auto Trans.

[Classicvibe]

Here is the first comparison data taken for analysis. For this I performed two tests on the right rear panel section. The first with the mic outside the van (6") and the source 4' from the van (and 4' off the ground as well), and the second with the mic centered on the back seat (source in the same position).

I used a full spectrum audio test for this (http://www.audiocheck.net/testtones_sinesweep20-200.php - Logarithmic). I will use other sounds as well, but I am wondering, is this data useful? I can see the results, but I don't understand this enough to recognize if this data will be useful. It appears that I am recording decibel level at different frequencies which I like. Who knows if it is accurate enough to show a few decibels in reduction. Perhaps that sound file is unrealistic in measuring real world sounds? I dunno Yo! But my new mic is pretty cool. It takes two people to do these tests so I gotta rustle up a neighbor kid and pay him a couple of bucks. More tonight if this is all a go, lemme know.

_________________
On a mission, the destination is just an excuse.

Syncro Solstice 2022...see you there!

1986.5 Wolfsburg Syncro Westfalia Poptop Weekender Transporter

[Classicvibe]

[randywebb]

yes, I started it - not sure where it all leads...

it is not hard to make a signif. improvement, esp. if you are rel. unconcerned about added wt. (Vanagon)
_________________
1986 2.1L Westy 2wd Auto Trans.

[Classicvibe]

[a914622]

I used the peel and stick from Master Mccarr. It was 16.00 for a 32x54 sheet. I used it on the inside of cnc milling machines to keep the sheetmetal from howling.
They also sell the "slug" stuff and the foild back closed foam stuff as well.

Do you have any noise numers yet? Im really intrested in the level at freeway speed.

Keep up the good work

jcl
_________________
87 gl powerd buy 2.5subaru
75 914 getting 2.2t subaru scratch that SVX subaru

[pinealservo]

[randywebb]

BTW - I sent the sounddeadendershowdown guy an Email about a month ago with no response, so...
_________________
1986 2.1L Westy 2wd Auto Trans.