Octavia Wagon sound deadening

[dportaz]

Might pick your brain before I do it all Mike...

Martin, ive got an annoying rattle coming from under the rear seat so I whilst ive got everything off, I might put some of it there anyway...

Do you guys suggest just both dynamat/supershield and rubber/felt or will just the dynamat/supershield do fine...?

Daniel

[MountainBikeMike]

Depends on how much cost and weight you want to add. The mlv is super heavy, buy it does a great job is applied with no gaps over the floor and spare wheel as a big sheet. Sound deadener isn't much weight or cost if you use less than 30% coverage. Foam/felt is a lot lighter, but thicker, and it doesn't absorb airbourne sound like mlv does.

The key thing to remember is sound deadener alone reaches a point where it can do no more very quickly.

Sent from my HTC One X using Tapatalk

[Martin]

Martin, ive got an annoying rattle coming from under the rear seat so I whilst ive got everything off, I might put some of it there anyway...

Hmmm, there's not much under there to rattle
There is some wiring to the fuel tank
The slide squabs that are attached to the car - the bottom attachment may not be correctly engaged
Otherwise it could be from under the car - there is an aero V - sometimes we wipe it out - sometimes half of it is left dangling and clicking on the road

[dportaz]

Hmmm, there's not much under there to rattle
There is some wiring to the fuel tank
The slide squabs that are attached to the car - the bottom attachment may not be correctly engaged
Otherwise it could be from under the car - there is an aero V - sometimes we wipe it out - sometimes half of it is left dangling and clicking on the road

Well not to sure what it is because I get rattles sometimes at idle and then at takeoff... Drives me nuts and want to get rid of it asap...

I don't think I need to do the mlv... Its fairly quite in the car already, just want to fix the rattles and then the std resonating sound from the rear on freeways etc...

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[Martin]

std resonating sound from the rear on freeways etc...

Indeed - that's the thing that fatigues you on long trips
Mine is much more peaceful now - very happy

It's temping to do the firewall but that's a very difficult task

[wfdTamar]

Dynamat Extremed my boot on the weekend. Did complete coverage of the whole floor, spare wheel well and wheel arches, quite a lot of the panelling behind the boot side panels (maybe 40-50%) and the rear panelling under the tailgate. Also about half the width of under the rear seats (so far). Haven't done the tailgate.

Used 8.5 sheets! I reckon if you only did the 25-30% coverage you might get away with one 9 sheet pack for a whole car, but for the sort of coverage I did needs at least 2 packs, if not 3 if you're also doing the doors. What I got was the older black (with silver logo's) stuff and it's really hard to see things on it so get the sliver, if not a different brand that doesn't feel the need to plaster their logo all over it.

Here's some photo's showing the stripped car with just the factory applied sound deadening, how much Dynamat I put in (and how terrible it is to find things dropped on it), The rear door speakers and door undressed.

Untitled | Flickr - Photo Sharing!

(Photo's now in posts below)

A few tips - Apply sheets from a centre line down the car, not from one side to the other. That way it's symetrical and once you've cut a sheet from one side it's easier to work out how to cut the mirror side one. For a really neat finish use the Dynamat finish tape on joins since the edges of the sheets ooze butyl and it gets on your clothes when you kneel on it. I used one roll just in the boot.

I did each of the 7 sections of the spare wheel well walls with a seperate panel of Dynamat as there is a compound curve at the top edge. I only left the central bit (about 50mm in diameter) of the spare wheel well free of Dynamat.

I was considering some 1/4" Dynaliner as well, but this is really getting pricey and I reckon the whole car floor would use about 4 packs of it!

I'll take after photo's when I put my stereo upgrade in and sound measurements when I've gone for a drive.

When you take the door panels off you will inevitably break the plastic clips holding it on. Here's they type they are:

http://www.ebay.com.au/itm/160968028502?ssPageName=STRK:MEWNX:IT&_trksid=p3984.m1439.l2649

[wfdTamar]

Getting another 2 packs of 9 sheet bulk packs of Dynamat Extreme and 4 packs of 1/4" Dynaliner - sodding car better be quiet and cool enough to sleep in after this.

A box of Dynamat Extreme (9 sheets) weighs 7kg (that's just the sheets, not the box).

[wfdTamar]

I used 2 boxes to do the whole car (tailgate, wheelarches, complete floor through to the firewall, firewall about 300 mm up), except the doors, which I reckon will take 5-6 sheets.

[bobski]

How are the results?

[wfdTamar]

With just the boot done (and rear wheel arches), not any notable difference measured with a sound meter, but it's definitely quieter from the back. I now notice the noise at the front more (front tyre noise, wind around mirrors).

I drove it with all the interior out of the main compartment and the floor done with Dynamat and then noticed how much noise comes through the doors (it's like renovating). Under the carpet there's about 25mm of cotton wadding underlay which does a fairly good job and dense foam rubber at the firewall. If you wanted to do a really good job you'd replace the floor wadding with Dynapad (the heavy one).

I won't be testing it with just Dynamat Extreme and all the interior back in - I'm putting in DynaLiner (this is more for heat than noise).

Doing the door inner skins too - at the same time putting in a fancy Polk Audio upgrade (speakers, sub, amps & processor)

http://www.vwwatercooled.com/forums/f78/planning-nice-audio-upgrade-rns510-octavia-94253.html

I've used 2 whole 9 sheet packs on the floor and each door takes a sheet.

[brad]

How much weight would all this be adding?

more photos required

[wfdTamar]

Ok, try again with bigger photo's.

Each box of 9 sheets of Dynamat Extreme is 7kg. The Dynaliner weighs hardly anything - each 810 x 1370mm roll is 500 grams.

I used Flickr for photo's before. It's just far easier to go from iPhoto to Flickr, but here they are below.

Here's the interior stripped prior to installing Dynamat. You can see there is a reasonable amount of factory deadening.

[wfdTamar]

Some more:

That's one of the sheets you get in a Dynamat pack.






This is the quite dense foam rubber that's at the firewall.

[wfdTamar]

Some more:


That's the underneath of the firewall rubber you can see.




The rear door. That aluminium plate is riveted on and has a foam gasket. It seals quite well, but on the front door ones I put one screw in outboard of the speaker hole.




I put these in so you can see where the panel clip points are. Virtually impossible to remove the panels without breaking the clips as they're very brittle (and even some of the mount points for the clips on the panel can break). You'd want to get some new clips before you start.

[wfdTamar]

Here's the type of panel clip:




After Dynamat Extreme. I went for pretty much complete coverage, but apparently you get close with 30%, as it's not so much noise blocking as vibration absorbing.

For noise blocking the heavier Dynapad is best and that really needs to be laid over the whole surface to work. It is 1/2" thick though, not peel and stick, or as flexible as Dynamat Extreme and Dynalayer and weighs 1 pound per square foot (don't know what that is per square metre).