Sound Deaden Engine Bay

peregrine

peregrine

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Sound deadened CJ engine bay, mainly under bonnet, so with slight variation would suit other mod
Under bonnet as I didn't want to affect airflow over the top of the engine due to warranty considerations,
decided to stick with the existing crappy 1mm!!?? ( be careful when removing very fragile New $104)
sound deadening item and fill in the spaces between it and the outer skin of the bonnet. All products I
used are from Clark Rubber (next picture shows items). Glued with spray on glue (Clark Rubber and Autobahn)
Formshield 12mm foam side to outer bonnet skin (not shown) cut smaller to fit outer skin only,
otherwise too thick to fit between outer skin and original item. next cut and fit Grey foam 12mm in spaces
shown glued to metallic side of Formshield. Make sure to use glue on both surfaces at all time
replace original item.
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Done

Materials used
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Next stop noise going through windscreen place self adhesive strips as shown in photo below
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Strips used 25x20mm on side of mudguard and under bonnet.
18x20mm shown in front of windscreen was later placed under bonnet.
Warranty problem?
 
The other question would be are the bonnet foams you used flame retardant in some way, and or fuel proof ?
 
Hi t-nol thanks for your response,, foam will ignite to direct contact to flame as will many other items under the bonnet but the bulk of it, except for two small areas completely out of harms way at the front, are protected by the original item. Blocking water exit , cant see a problem
appears to be enough holes in the grill in the photo. Hits the ridge just in front. Have been contemplating placing that piece to underside of bonnet for more secure fitting.

Any suggestion of alternative materials or ideas would be great.

Checked DB reading at idle now down from 46db to 38.2DB. As this included sound proofing the boot and have no reading for that, cant qualify any help from that.
 
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Have you though about buying bulk dynamat and going crazy on the whole cabin and doors?
You'd never have to buy lowering springs because you'd be heavy enough to get a nice drop out of the springs.
 
38dB holy *poo*. My car isn't even that quiet when it's off. I think if you drive my car or even Hughsey's car for 10mins you'd want to kill yourself. I don't think it gets quieter than maybe 70dB lmao.
 
Hahahahh, mine doesn't even have the plastic on the door cards. Driving wind makes noise.
Pretty sure my idle is more than 38db
 
That's awesome, good job on the soundproofing. I think my fridge run's at 40db so you beat it , and its a Mitsubishi fridge, on the positive or (neg) side if you have a bearing/belt failure under the bonnet at least you won't hear from it till you finally stop!
 
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Hi Hugh-CE, Materials I use are light weight by comparison as are some of the Dynamat products.

Presume sound deadening used in boot, under bonnet, under body, next, wheel wells and I mean going under the splash shielding front and rear, plus later doors and cabin floor.
Should only weigh, maybe as much, as carrying a young child as a passenger. Which is about the amount of weight I have lost in my dote age, now weigh just 82kg. Equal to my age. Ouch!
 
That is an intense amount of sound deadening. I'm curious, any reason behind it other than wanting to drive on a cloud of silence?
 
Yeah, I'd definitely be getting dynamat for that. It'll make your life so much easier. You'll also get awesome sound quality of your stereo.

The Spring sag was a joke haha.

I know for my old man it was so much easier to hear when it was silent as the white noise of the road drowned everything out. Same reasoning here?
 
Hi Hugh-CE On coming Macedon meet must be keeping you busy. Have been using 1 ply 1.3mm rubber instead of Dynamat, has worked well to stop drumming - vibration of panels at a fraction of the cost. Weight probably about the same.

Contemplating using Dynamat when I do the doors and wheel wells. on outer skin as I feel will maybe give me a better seal to the metal it shields, due to these being areas where water flow could be a contention.
Also have some 3mm closed cell foam (doesn't absorb water) for use, for some areas.

Re stereo, original limited not great. Better speakers could make a difference. Not important for me.
 
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rigby said:
That is an intense amount of sound deadening. I'm curious, any reason behind it other than wanting to drive on a cloud of silence?
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Hi rigby, Riding on a cloud? Of silence, not expected but would be nice. Of ride, impossible it is a little Lancer!

Estimate sound deadening to cost around couple hundred $$ maybe.
 
Lol not organising people, it's organising parts for the car so it performs how I need it to. (Brakes) to avoid death.

Yeah I would go for dynamat especially for the doors and stuff. It'll be a lot easier to apply and it's such a proven technique.
 
Dynamat and foam block different sorts of noise though. Ideally you would put Dynamat on and then glue foam over the top.

I started doing that in my CJ when I had it and it seemed to work well. Doing alot of the car in Dynamat starts getting expensive but I needed alot throughout the boot to stop the rattles from my ridiculous sub :lol: . The foam on the other hand was fairly cheap from Clark Rubber.
 
Ryan said:
Dynamat and foam block different sorts of noise though. Ideally you would put Dynamat on and then glue foam over the top.

I started doing that in my CJ when I had it and it seemed to work well. Doing alot of the car in Dynamat starts getting expensive but I needed alot throughout the boot to stop the rattles from my ridiculous sub :lol: . The foam on the other hand was fairly cheap from Clark Rubber.
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For Boot.Used Clark Rubber, insertion rubber 1.5mm to stop panel vibration and drumming, successful. Then foam on top of it and where needed and possible. Then original lining, carpet? Rubber and foam allover, boot interior, floor, rear quarter panels, boot lid,
spare wheel bay etc. making sure interior air flow wasn't interrupted.

Yes I believe Dynamat is a great product and will be using it elsewhere, especially interior of outer door skins and areas where moister can be a problem. Not that I believe the rubber could be a problem ......but better to be 100 present sure then sorry.

Side issue, boot now closes with a soft deep thud and not a clank!
 
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t-nol said:
Aren't you blocking the water exit there?
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Rather late response. I wasn't having any water problems and even went to car wash and concentrated flow onto windscreen and directly into vents
with no adverse effects.

However due to your question, I got to thinking. Well,would it stand up to a deluge? So have made alteration to allow water to escape over and down the front just in case.
Not quite as freely but yes it can! Overlapped rear seal behind the original with a gap between them. Overlapped to defuse sound track and it retained existing sound levels
with only hard to explain slight change to sound tone. Prefer the way it was but at these low levels and only at idle, what the hell!

Thanks for your caution!
 
rigby said:
38dB holy *poo*. My car isn't even that quiet when it's off. I think if you drive my car or even Hughsey's car for 10mins you'd want to kill yourself. I don't think it gets quieter than maybe 70dB lmao.
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Thread still relevant as still more to go, haven't done anything for awhile. Will get on to it again soon. Complacent because car is now pretty quiet. Aged limbs makes hard work of it, getting around with a walker now. Like to be able to silence the heater - air conditioner.

Your car and Hughsey's wouldn't be a problem. Just turn off my hearing aids. Bingo!!! 15 db. Hahaha
 
You wouldn't have to worry about your hearing aids my friend, they would just rattle out! :grinning:
 
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