Installing Dynamat in 300Tdi

[travelrover]

Hi all

I know there is a thread that covers this somewhere here but i am unable to find it so apologies if I am covering old material.

I'm planning on installing Dynamat in my 300Tdi project vehicle initially on the firewall, floor and sides in rear. Later I propose to do the roof and maybe inside the doors if that's possible.
The first bit of the job looks reasonably straight forward but I have a question. As I am not planning to remove the dash just now (hopefully in the future) I was wondering if it is possible to get up behind the air con unit in the passenger foot well without removing it? Are there any tricks to this?

Anything else I need to be aware of?

Thanks

Simon

[manic]

If you are working with bitumen sound deadener you only need to place it on thin panels that vibrate. Its not very effective as a sound barrier.

Covering sections of seatbox, floor panels, footwell, roof panels and door skins will reduce the vibration, resonance in the vehicle. You dont need to get behind the dash IMO, it is fairly rigid. You can cover everything in the stuff but you are just adding unnecessary weight for very little additional gain.

[omy130]

A couple of links I've saved over the years. Hope it helps.

Soundproofing 93 Defender?

Sound proofing

Floor Insulation

Plus check out Bushman83. Go to his earlier videos. Has a few on interior mods.
YouTube

[Fubar]

Doing the whole cab myself right now. I only have a couple of pictures to date.

Starting to add in the 'Stage 2' foam insulation. A long over due addition.

[travelrover]

Doing the whole cab myself right now. I only have a couple of pictures to date.

Starting to add in the 'Stage 2' foam insulation. A long over due addition.

Looking good though. You have a lot more boxes than i do but mine is stage 1 i think. Too cold to look under the bench in the shed nust now. Have you done the firewall and floor also?

[Fubar]

Looking good though. You have a lot more boxes than i do but mine is stage 1 i think. Too cold to look under the bench in the shed nust now. Have you done the firewall and floor also?

Not yet...I have a bit of work to do with the aircon, rear seat area and dash upgrades so all that is a couple of weeks off.

Came home to find this, placed it yesterday.....not a sticky as the Dynamat, I'm ordering more Dynamat tonight. Not impressed with the Carliner sound deadener.

[Dorian]

If you are working with bitumen sound deadener you only need to place it on thin panels that vibrate. Its not very effective as a sound barrier.

Covering sections of seatbox, floor panels, footwell, roof panels and door skins will reduce the vibration, resonance in the vehicle. You dont need to get behind the dash IMO, it is fairly rigid. You can cover everything in the stuff but you are just adding unnecessary weight for very little additional gain.

x 2.

Dynamat works by changing the frequency of the noise. It effectively moves the sound to a lower frequency and does little to reduce the amount of energy in the noise. This does makes the noise seem a lot less, where in fact it's just a lot less annoying, which is probably the result you are looking for. Appliying dynamat is akin to pouring honey onto a drum skin, you only need to cover about 30% of the surface area to get about 95% of the effect. Having said that I did all of my load area's and foot wells fully, so I retained an even surface, but the roof was 30% ish covered (probably 50% but couldn't help myself)

As an aside these type of products should be made with uncured butyl rubber, bitumen will sort of melt and fall off in summer.

The reason that the pro's use this product is that high pitch sound is a lot harder to stop than low pitch sound, so you use dynamat to lower the frequency so you can stop it with either a foam product or a mass loaded Vinyl.

If you have a look at the puma's they have front mats that are a mass loaded vinyl with a 3-4 mm foam separation layer. I think closed cell foams are better that open cell but I can't remember why. IIRC the foam reflects the noise and the mass loaded vinyl absorbs it.

Several years ago (maybe 4 ish) there was a thread re sound proofing that went on for 5 or 6 pages and a chap who was obviously an acoustic engineer gave a pretty good and short primer on the subject, sorry but I can't find it.

Cheers Glen

[Fubar]

Several years ago (maybe 4 ish) there was a thread re sound proofing that went on for 5 or 6 pages and a chap who was obviously an acoustic engineer gave a pretty good and short primer on the subject, sorry but I can't find it.

I think your man is Bojan (Offender90)...good info in post #17 of this thread.

The improbable task of silencing the 4bd1 county

Still looking for more sound threads with him in it.

[travelrover]

I think your man is Bojan (Offender90)...good info in post #17 of this thread.

The improbable task of silencing the 4bd1 county

Still looking for more sound threads with him in it.

Did you manage to remove the fir tree fasteners without snapping them?

[DeanoH]

I lined the interior of the Oka cabin with Dynamat about five years ago. The Oka has similar acoustics, or lack there of as the Defender, probably worse really as the Oka is a 'cab over' vehicle similar to a 110. It involved a fair bit of messing around but not terribly difficult. The main thing I learnt early on was to make sure the metal surfaces were clean and dust free to gain good adhesion and not to 'de sticky' the Dynamt.

I fitted a single layer to the floor and foot well sides and every other surface with a double layer to the engine sides, side covers and hatch. I covered it all with thin marine type carpet stuck on with contact adhesive. I also removed the internal door covers and covered the insides of the doors outer skin as well.

The result was remarkable. I don't know much about low freq vs hight freq, percentage coverage or any other technical stuff but I do know that I can now listen to the radio, CB etc without having the sound levels up high. I can converse with SWMBO without shouting and use the mobile phone, err ....... the passenger can use the mobile phone whilst on the go . Traveling is much more pleasant and comfortable.

It cost me around $600 at the time and was worth every penny and hour spent. Lining the inside of the doors made a significant difference to the overall outcome and is IMO definitely worth doing.

Deano