Soundproofing 93 Defender?

**Michael2** · 17th August 2012, 09:46 PM

Originally Posted by samuelclarke

Be very interested in how much of a difference the matting makes for you as I'm looking at it also.

Apart from noise I think it will make a big difference to summer heat.

On the last trip to the Pilbara, I noted that with the windows up and the A/C on the cab cooled a bit, but as soon as the windows were wound down, I could feel hot air rushing in through the seat box, like it was being sucked in by a venturi effect. The parts of the seatbox that were bare metal were hot (not burning) to touch.

Without a radiator battling my A/C, I think I should get cooler A/C. The problem with the Defender's A/C is not the temp, as it gets very cold, but that the fan speed doesn't match the internal volume of the vehicle, which means the back doesn't feel cool in hot weather, even though the front passenger is freezing.

I've also ordered the new door seals that fit on the bottom of the doors and come up in a U shape. That will allow me to remove the seal on the floor, and make sweeping out the floor a lot easier, as well as sealing the door better.

**wilga** · 18th August 2012, 06:32 AM

following this thread with interest , i am going to do my 130 dc i have been looking at fatmat / similar to dynamat . michael2 do you have a part number for the u shaped door seals

**Michael2** · 18th August 2012, 08:14 AM

Originally Posted by wilga

... michael2 do you have a part number for the u shaped door seals

p/n LR029309 - Britpart Link Britcar (UK) Ltd > LR029309 DOOR WEATHERSTRIP LOWER FRONT DEF (G)

At this stage only available for the front doors, I need to see if Land Rover have the rear door ones as a genuine item.

I've already bought two sets for mates, there was a mix up with my last order and I didn't get my set, but they're now on their way. They look like a good fit and seal the bottom door corners, that the original seals weren't good at doing.

I got mine from Parts and Accessories for Landrover and 4x4 they have been good with pricing at freight.

oops - my supplier didn't have the back door seals, but Britpart have them http://www.brit-car.co.uk/product.php?xProd=182674, I'll see if I can get them locally.

**Dockstrada** · 18th August 2012, 12:49 PM

I have been building an SL/R Torana and have just fitted some sound proofing it has a 383 stroker with 510hp so this was an important , it has made a huge impact on the cabin noise.

**Bigbjorn** · 18th August 2012, 03:55 PM

Went through this supplying small earthmoving equipment to the coal mines. Poor little darlings can't be exposed to a daily noise dose over 95 dba. Foil faced and lead filled closed cell foam is best and the most expensive. We had to get a consulting engineer in and much design work and modification was required including running the hot cooling air out through upwards slanting louvres lined with foil faced foam to deaden some of the fan noise. One type of machine the operator sits with a diesel engine at his back and a hydraulic pump train under his feet, an hydraulic motor at each hip. Bugger of a thing to quieten. We got down to 98 and the mine engineer agreed there was nothing else we could do that might work. He was on our side. The machines were urgently needed and only after he was in contact with the mine operations was he told they are only used for 45 minutes to 1 hour 3-4 times a week. Everybody off site was under the impression they were used more or less continuously for two shifts a day. Much swearing as the daily noise dose was recalculated. Much work did not need to have been done as the daily dose was well down on the permissible. Machines were signed off and despatched.

We did learn a lot though.

**wilga** · 19th August 2012, 07:58 AM

thoughts on this ? acoustiblokau.com.au/ should be good if it matches the claimed figures

**Dougal** · 19th August 2012, 08:12 AM

Originally Posted by wilga

thoughts on this ? acoustiblokau.com.au/ should be good if it matches the claimed figures

It's a building product, so you'd have to check it's okay with temperatures it may see in a vehicle and I have no idea how flexible/shapable it would be.

But as a mass layer it could work very well on top of insulation which is on top of the deadened sheet-metal.

**Michael2** · 28th August 2012, 08:34 PM

It's taken me awhile, and I still haven't got all the comparative figures, but here are some sound level readings.

OUTSIDE OF VEHICLE

Bonnet Open, sound meter just above the radiator.

TD5 80dB
300Tdi 81dB (79dB after a long run)

Bonnet Closed (sound meter in same position)

TD5 D2a with standard factory insulation 69dB
300Tdi with standard factory insulation 72dB
300Tdi with acoustic mat fitted under the factory insulation 67dB

INSIDE OF VEHICLE

TD5 D2a @ Idle 50dB
300 Tdi @ Idle (with Exmoor Acoustic Floor Mat only) 55dB
300 Tdi @ Idle (with Exmour Floor Mat & extra under bonnet insulation) 55dB

I've got driving figures for the 300Tdi 110SW with the Exmoor Trim (but no extra under bonnet insulation). As soon as I get the comparative figures with the under bonnet insulation, and the standard 110SW, and the TD5D2a (benchmark), I'll add those.

But just as a sample, if I rev the 300Tdi (with acoustic floor mat) to 3,000rpm in neutral (stationary) the cabin noise (prior to extra bonnet insulation) was 76dB. Driving the car at 100kph in 5th with the Roverdrive engaged the sound level was 74dB, suggesting most of the noise is coming from the engine, and not road / transmission, so that's where to concentrate the sound control effort. Incidently tyres are Michellin LTX AT2 - a quiet AT.

It does sound quieter in the cab driving with the bonnet insulation, though idle readings haven't changed, but I haven't yet done a quiet run (radio off - sound meter on) to gets figures.

**MLD** · 29th August 2012, 02:46 PM

Michael - I couldn't quite work out your under bonnet insulation from the various posts. In summary, what product did you use, what coverage area. Did you use multiple products and how did you layer (integrate) them. Did you pay any particular attention to any areas. What glue did you use.

I did an install in the cabin a few weeks back but ran out of product. I raised a post in the projects section on the forum. I'm re-stocked with sound deadener, EVA foam and 500 deg heat insulation matting. This weekend i'm going to tackle the bonnet and floor of the rear seat. I plan to lay the butyl insulation against the bonnet then a layer of eva 6 mm foam and then the heat matt. All up about 12 mm of insulation.

If you learned any lessons under the bonnet I'd be interested.

cheers Mark

**Michael2** · 29th August 2012, 05:57 PM

Sorry, I didn't make it clear.

Under the bonnet I used a mat with open cell foam, a loaded vinyl sheet layer and an aluminium face. I wasn't keen on open cell, but decided to buy this as an off-cut to try it out. It's a Bus / Marine engine bay insulator, usually $75 p/m. I got a couple of meters of off-cuts for $50 to try it out.

I removed the felt insulation, padded the hollows of the bonnet with this stuff, then put the felt pad back on using self tapers instead of pop rivets. Because it's in the experimental phase, I didn't glue it, but it's still snug. I'll see how it fares after I go through some puddles in the next rain, before deciding on it.

It does demonstrate though that extra under bonnet insulation can easily exceed the D2 standard (front of car) and go a way toward improving things.

Powering uphill at 80kph today was 72dB.

I probably won't get time till next week now to do all the sound testing, but I think a firewall cover would also help greatly, the D2 has a 10-15mm foam over the whole firewall.

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