Bonnet soundproofing

I've just fitted the Noisekiller under bonnet kit- looks like Dynamat. Will report back on any improvement after my long drive tomorrow. Back is well insulated as previous owner had lined the tub with ply and topped it with carpet. I've added a storage box covered with thin rubber matting. Thinking about the Exmoor moulded matting for the cab. Has anyone tried it?

SpaceDawg said:

The can noise has come down from 88-90db at 55-60mph to a flat 80. To put this in perspective 90db can damage your ears permanently after 3 hours exposure on a regular basis. 80db should not cause any damage.

So yes its worked, but I have not finished, I have the rear tub and roof to do now, this should knock a few DB off.

It's still noisy, but all the crap noise has gone. Just need to get the Tub rumble and bell sounds to go.

Click to expand...

After sound proofing the tub floor and over the wheel arches its made no difference in the from still 80db, but the back has come down from 85 db to 80db. Just the roof and back door to do now.

Really easy jub; just highlights some other noises thats all.

I'm in various stages of noise insulation on my Landy. As it stands, it had absolutely nothing, not even floor mats. I've glued foil backed camping mats to the ceiling and sides. That's made little difference to noise but it has greatly reduced condensation when cold and damp and stopped it feeling like an oven in strong sunlight. It's also reduced external noise coming in. I am in the process of covering this all in ply which will also be covered in carpet. I'm expecting the combination of these to make a bit of a difference.

For the load area, I'm going to cover it in flashing, then camping mats, then ply, then carpet.

The bonnet i'm covering in flashing then foil backed mats.

I'm expecting the biggest improvement to come from the 1.2 disco transfer box which I'll be finished fitting at the end of the week, as this will reduce revs.

When I can be arsed, I'll be taking the engine out and giving the bulkhead the flashing and foil backed mat treatment.

The cabin area, I want everything to be removable so I will probably buy a kit that can be removed easily.

I've got all the stuff and I'm just doing it bit by bit when I have time.

EDIT: Also, I've changed the gearbox and tbox mounts for high quality ones to reduce vibration. Will do the same with the engine ones.

you need to knock out different frequencies and vibrations just like car manus do

so bit of mat in the center of a panel for vibes.

foam like the mat for the highs and thick loaded stuff like mass loaded vinyl for the lows.

normally vehicles have the foam glued on the back of the loaded mass

Didn't find under bonnet to make much difference in my opinion.

I've slowly been sound / heat proofing my 110 van 200tdi,
Wright mat made some difference but I could see light below the doors so...
New type bottom door seals glued on with sticks like s**t, new galvanised frame doors I didn't want to drill. That's been on for two years now and not come unstuck.
Now quite a bit quieter
Full underbonnet similar to eBay shown before, plus rubber rocker cover pad, this reduced engine noise to less than the back of the van.
Covered floor walls and ceiling with flash band this reduces panel wobble sound so could hear road noise. Cab and body.

10 mm rubber matting on rear floor, clad walls and ceiling gym mats. Further reduced road and other noise
Clad walls and ceiling with wood cladding made higher notes disappear.

In process of building partition on rear bulkhead, well 6 inches behind it, but stepping forward to join.
No window in the middle yet, just a hole and not sealed to walls or ceiling. But this has made a huge difference the engine is back to being the main noise but much lower tone to it.
Once I've windowed , and sealed the partition and the rubber / carpeted the drivers side.
Then its back to the engine compartment, I'm thinking of fat matting under the bonnet pad,, fat matting the bulkhead. Using Armaflex, on all other panels to absorb the noise.
I've seen on some foreign forums, use of transmission blankets to good effect, so I'm looking at that as well.
As for water leaks , captain Tollys creating crack cure, worked on the windscreen rubbers, and roof to wall joins. Running sealant along the top of the air vents helped a lot, the vents still work and it will do until I have time to remove them and replace the seals.
Also running sealant just under the door top rubber also helped..

Holly crap, we went and bought some 13mm stable matting £39 and just chucked it in the back of the 90 yesterday and its took the noise levels down a lot, I'm probably going to cut ant fit it properly at the weekend to finish the tub, but its made a massive difference to the terrible noise from behind, just to roof to do next. I would like to find a roof liner for the back as well then I'm done with Jo for now.

Rachel and I managed to talk normally at 55mph yesterday ! Sure there's a joke there somewhere.

Then I'll do the wheels, radio, rock sliders, paintwork etc.

SpaceDawg said:

Holly crap, we went and bought some 13mm stable matting £39 and just chucked it in the back of the 90 yesterday and its took the noise levels down a lot, I'm probably going to cut ant fit it properly at the weekend to finish the tub, but its made a massive difference to the terrible noise from behind, just to roof to do next. I would like to find a roof liner for the back as well then I'm done with Jo for now.

Rachel and I managed to talk normally at 55mph yesterday ! Sure there's a joke there somewhere.

Then I'll do the wheels, radio, rock sliders, paintwork etc.

Click to expand...

That's a good suggestion about the stable mats. I think I'm going to look into that one.
What are you going to do about the wheels? I bought a set of Modular ones from Paddocks a couple of years back and they are rusting up and the paint is coming off them already.

I can either get the ones I have re-painted at £60 each or buy new ones, not sure yet.

Further to my notes above on my sound insulation, I've also bought one of those cheap sound meters.
I note that from another website a Defender 2.5 N/A van with no insulation at all reached 95DB when going at 60!
In it's current state the 110 give the following readings, with the noise meter sitting in the front of the cubby box tray.
Engine off, 35Db
Engine on tick over, 60Db
Driving on smooth 'A' road at 60, 75Db, if the vents are open 83Db.
Bouncing along country lanes, 85Db intermittently.
Clanging about, putting on Disklock 95Db peak!
Most of the noise is definitely coming through the bulkhead, mostly a low rumble.

Oh and I agree about the modulars going rusty very quickly

+1 for the stable matting. I used the 19mm stuff to line the footwells and floors, back and front. Cheap, easy to cut/fit and has made a big difference to engine and transmission noise. Cheapo carpet tiles in dark grey stuck to the rear (sides and roof) have removed the van body booming, and condensation is gone!

Just going to throw my 2p in here. I've been working rather hard to reduce the sound levels in my 90 and have had very good, very noticeable success. Heres my current set up -

Fatmat Xtreme - Very similar to Dynamat but cheaper, thicker and better. Butyl based aluminium lining
Seatbox
Footwells
Transmission Tunnel
Rear loadspace - This made an enormous difference
Rear Arches
'B Pillars'
Currently doing the roof.

Then I have the CSW rubber matting throughout which I have ripped the ****ty open cell foam that LR fitted and replaced it with self adhesive 3mm closed cell foam (does not absorb water). This step further reduces any vibration and deadens sound

B-Pillars where lined with 10mm closed cell foam using high temp spray adhesive, then a layer of 3mm over the top. Multi layering increases the soundproofing qualities.

Plastic interior trim was then lined in certain places with 3mm closed cell foam to ensure it doesnt rattle or vibrate against the metal body work.

Finally lining the roof with open cell acoustic foam as shockingly roof is leak free so I dont have to worry about absorbing water. I havnt done this yet though. Then the LR headlining over the top.

Its £149 for 50sq/ft of Fatmat which is enough to line the seatbox, foot wells and transmission tunnel, even double layered in some places.
About 25 - 30sqft for the rear loadspace (90), wheel arches, B pillars and front roof section.

Closed cell foam is 2m x 1m self adhesive backed is £20.99 you will need double that to cover the front matting and loadspace matting with a bit left over to fit where ever you like. The self adhesive sheets glue is not good enough if it is against heat, i.e direct to the roof. Use high temp spray.

Over all I have probably spent around £350.00 and probably 24 hours work to get it all done properly. It is probably worth mentioning I have a straight through exhaust so its not exactly quite but with all the above its not noticeable. The soundproofing works so well that I didnt even notice when I forgot to refit my main speakers! Everyone that gets in it now is shocked by how much the noise levels have reduced. When im finished ill do some db tests.

Ok update on this, firstly my spedo was overeading, after the sound measurement I made and since fitting a gps the reading qas 80db at 46mph.

I replaced the diff at the weekend just been out for a run at 50mph on the gps its now 77db, goes to about 76 at 46mph. I can now hear the tyre rumble as I'm running Khumo KL71's I can now also hear the engine and another whine at the front.

I still need to do all the door seals and soundproof/insulate the roof and doors then I will be done.

But at the moment its a hell of a lot more nice than it was.

bankz5152 said:

Just going to throw my 2p in here. I've been working rather hard to reduce the sound levels in my 90 and have had very good, very noticeable success. Heres my current set up -

Fatmat Xtreme - Very similar to Dynamat but cheaper, thicker and better. Butyl based aluminium lining
Seatbox
Footwells
Transmission Tunnel
Rear loadspace - This made an enormous difference
Rear Arches
'B Pillars'
Currently doing the roof.

Then I have the CSW rubber matting throughout which I have ripped the ****ty open cell foam that LR fitted and replaced it with self adhesive 3mm closed cell foam (does not absorb water). This step further reduces any vibration and deadens sound

B-Pillars where lined with 10mm closed cell foam using high temp spray adhesive, then a layer of 3mm over the top. Multi layering increases the soundproofing qualities.

Plastic interior trim was then lined in certain places with 3mm closed cell foam to ensure it doesnt rattle or vibrate against the metal body work.

Finally lining the roof with open cell acoustic foam as shockingly roof is leak free so I dont have to worry about absorbing water. I havnt done this yet though. Then the LR headlining over the top.

Its £149 for 50sq/ft of Fatmat which is enough to line the seatbox, foot wells and transmission tunnel

Click to expand...

+1 for Fatmat. Mine is done completely in the cabin and under the bonnet. It's also ply lined and carpeted. The difference is amazing.
I don't think I could do 50 mile a day down the motorways or the caravan holidays without it