General Soundproofing

[redvtec]

Has anyone sound proofed their car?

I have had various cars in the past my jag being silent, I would like to soundproof the stilo for motorway trips as it's quite wearing. I used a db app and was reading 90db which is loud.

I don't want to spend stupid money, I have roof flashed the boot floor and also fitted some under felt under rear seat, boot floor. I watched a super car build program on rolls Royce and noticed that they fill the cavities with something along the lines of thinsulate insulation. I don't want to spend out in that as funds are tight, but I do have a load of Rockwool insulation, could I use that?

Ta

 

[Ralf S.]

It's a tricky one since your car is getting on a bit and you don't want to spend much money on it...

If your bearings/driveshafts are a bit worn out they will make noises which new bearings/driveshafts would not.

If your silencer is a bit ropey or a cheap after-market, then that might be more tinny than a new thicker gauge/quality one.

If your tyres are "old" and "budget" then they will make more noise than "new" and "designed for low noise" (i.e. more expensive).

Assuming you can't change any of the above... then you want that sticky rubber mat/mastic applied to any metal surface that attracts noise (since it amplifies it).

So, stick the rubber mat inside the spare wheel well, on the boot floor and under the carpets inside the car (you'll need to remove the seats and lift up the carpet). Pay particular attention to the wheel arches and the bulkhead... but these last two will respond to some felt lining too (the stuff the bonnet lining is made out of).

While you're dismantling the interior, the rear boot carpet can come out.. Fit some of that felt mat stuff to the inner rear wheel arches too.

You can also line the doors/rear 3/4 panel with the black mastic stuff. Stick it directly to the door skin, not the door card. Don't stick it to the underside of the bonnet, or it'll fall off with the heat, catch fire and your old ship will have a premature Viking's Burial...

If your bonnet liner is missing (or your model didn't have one?) get a second-hand bonnet liner.

If you have no under-tray (and these live in the realms of unicorns and rocking horse poo) get an undertray:

http://www.ebay.co.uk/itm/191564148838?_trksid=p2055119.m1438.l2649&ssPageName=STRK:MEBIDX:IT


If you have a fetish for rubber.. take the wheel arch liners out and get someone to give your inner arches a coat of underbody Shutz. You need pukka spraying equipment to apply it (not easily DIY).

You can also wrap the exhaust downpipe and the pipework in between the silencers and the cat' with exhaust bandage.

By now your car will weigh 20kg more but should be a little bit quieter than before so that you'll become annoyed by all the squeaks and rattles that you couldn't hear before..


Ralf S.

 

[Artermis]

The stuff you want is Dynamat sound deadening. You can get kits of guides for some cars that tell you where to place the sound deadening to absorb the vibrations in the chassis / shell to make most effective use of it.

I can't find any such reference to anything for the Stilo though, unsurprisingly.

That being said the stuff is expensive. If you went as far as to cover the floor, ceiling and accessible side panels of your car with the stuff you'd probably spend what the car is worth in sound deadening material.

Regarding rockwool... I'd recommend staying well away from doing that. You'll just create condensation and moisture traps and rot your car from the inside out. Besides which there isn't enough 'dead space' that you could fill with it to make any real impact.

90db sounds rather dramatic. In the health and safety world 90-95db is considered a dangerous level for prolonged sustained exposure.

Are you sure your exhaust is in good condition and isn't an aftermarket chav enhancer? Tyres also make one hell of a difference. You're looking around 68db for a good tyre vs 73db for a bad one, which across an axle will make a difference. Alignment also helps. If alignment is out it will make them noisier.

I can't honestly say I'd considered my Abarth loud. For reference I have an Audi A8, that's as sound insulated as you're going to get in a car. The dam thing is double glazed even. Its a V8 twin turbo diesel with straight through, completely un-silenced exhausts from the cat back and I can't hear it in the cabin. It runs on 245 section 19s which again, you can't really hear.

From that I've never stepped into my Abarth and thought good lord the noise in here is deafening.

 

[Alfettaman]

I agree with Artemis on this. Also, Rockwool sheds tiny fibres everywhere and is a serious respiratory hazard and skin irritant.

I too don't think of my Abarth as noisy. It's certainly much quieter than my (completely standard, brand new and quite expensive) BMW R53 MINI Cooper S was, and the noise that the Fiat makes is a nicer one Perhaps Ralf's idea of tracking down and fixing the noisy components is worth considering?

My Stilo also has no creaks or rattles at all: is that unusual? I just assumed they were all like that (this is my First Stilo), but maybe I got the good one...

 

[redvtec]

Thanks for the replies, I should point out I have a land rover defender as well, so have experience with sound proofing a loud car.

I know the thinsulate stuff does not hold water so you don't get the condensation issue. I don't want to spend to much as to be honest if I go down that route I may as well chop it in for another car such as BMW compact or an older S3. I like the stilo as its practicle. Also dont want to waste time doing stuff that has no benefit

Regards the db I used a phone app and it was reading in the 90 area, which is high. the car is an 05 plate 1.9 JTD 115 running on blades I need to look up tyre make, it could just be those. Exhaust is original. I did think of wheel bearings, but don't think its that rumble you get with them, its to cold to look at the mo.