Soundproofing

Oscar · Post by **Oscar** » Mon Aug 22, 2005 2:55 pm

Hello

DOes anyone have any experience of soundproofing their BX? Any tips or tricks? On the cheap, of course.

I like to be able to hold a conversation without shouting...

Oscar

tom · Post by **tom** » Mon Aug 22, 2005 3:13 pm

Change the engine and gearbox mountings. The difference is amazing. Do this first. Then give the window seals the Paddington Stare.

Oscar · Post by **Oscar** » Mon Aug 22, 2005 5:46 pm

Tom

Thanks for the quick reply. GSF show 4 - upper RH, lower disk, left hand (gearbox side) and a gearbox mount. Should I order all 4 do you think?

And are they tricky to fit?

Thanks again.

Oscar

Vanny · Post by **Vanny** » Mon Aug 22, 2005 7:27 pm

er, there should only be 3! upper, lower and gear box! im sure someone more knowledgable can tell you why i'm getting it wrong and what goes where (i guess if you count the two on the side of the engine mount there are 5 and two are identical so that will probably solve the problem!

As for an advance on sound deadening in the cockpit, try Dynamat (stop whining that its £50 per square meter or something stupidly rediculous!). basically you want to line all the panles with it, so inside edge of the door skin, inder the floor pan carpet, roof liner), use some spray advesive (stuff used to stick vinyl and carpet tiles down is awesome!) to make it stick to the doors and roof, but leave it loose under the carpets. Now here is the trick come trade secret. Goto machine mart and order a role of floor safety matting, it comes as 1metre by 5 metres in a range of thicknesses some times and costs, £25! rather a lot ceaper than dynamat! I use a HUGE piece to line the boot and it goes half way up the sides so when LHM/oil/liquid spills i just pick it up and pressure wash it down!

It obviously adds weight, but theres no way to reduce noise without adding weight! Just dont do what i've heard of a capri owner doing, wanted to reduce vibration and get a better clunk sound when closing the door, so filled the bottom of them with concrete!

ken newbold · Post by **ken newbold** » Mon Aug 22, 2005 7:32 pm

Nothing wrong with concrete! If I had a Capri thats what I'd fill it with.

Geoffrey Gould · Post by **Geoffrey Gould** » Mon Aug 22, 2005 9:53 pm

Talking of concrete which we were sort of, some time ago (long time) I used to be an mot tester, in the sixties, a Vauxhall Viva came in and had had the chassis legs undersealed and they didnt look quite right. Holes had been drilled in the boot floor and the chassis legs etc had been filled with concrete using card board as a 'former' for the shape where the legs were not there anymore. It failed, the chap was not best pleased.
Cheers.
Geoff.

cavmad · Post by **cavmad** » Mon Aug 22, 2005 10:12 pm

ken newbold wrote:Nothing wrong with concrete! If I had a Capri thats what I'd fill it with.

And oddly enough a lot of them genuinely were. It was a handling remedy that actually worked, at least on the 3 litre versions. A bag of cement either side in the boot improved matters no end. Never got the chance to do it on the 3.0S MK3 I once had as I didn`t own it long enough to worry about. One seriously quick car (in it`s day) I sold it for an offer I just couldn`t refuse and it was a right old mess too.

Oscar · Post by **Oscar** » Tue Aug 23, 2005 9:54 am

Noisekiller quoted me GBP173 for a BX soundproofing kit, 20 sheets, 4 pads, cut to size.

www.noisekiller.co.uk

Sounds reasonable compared to Dynamat at GBP50 per sq m, cutting it to size oneself and the potential for error, injury etc.

Mike E (uk) · Post by **Mike E (uk)** » Wed Aug 24, 2005 12:58 am

Mine quietened down nicely when I increased the final drive ratio
of 5th gear. Much better on the motorway.

MPG went up too.

Mike

Oscar · Post by **Oscar** » Wed Aug 24, 2005 11:11 am

Yes Mike I was thinking more sticky-back plastic than spanners - my technical skills are limited and don't extend to ratios in gearboxes

but it may be worth writing the procedure up for others who are more competent and would give it a go (maybe even myself in the future!)

How about it?

Oscar

Mike E (uk) · Post by **Mike E (uk)** » Thu Aug 25, 2005 6:33 pm

Hi Oscar, since you asked:

(re-print from bx16valve.com)

If you rarely use motorways this will not matter to you, but I found the BX16V high revs at speed wearing on long trips. This is a pity as otherwise the car is good for long distance travel.

So I have now modified my 5th gear from
20mph / 1000rpm
to 23mph / 1000rpm.

70mph was 3500 rpm, now 3000
80mph was 4000, now 3500

This reduces the engine noise significantly, and the cruising
comfort is much improved.

The acceleration in top is reduced , but to overtake you would drop
to 4th gear anway.

The modification is to swap the two 5th gear cogs for those from a turbo D.
There is a sleeve that must be ground down 1mm in diameter to fit the larger cog,but apart from that just follow the Haynes manual.
( Ask me if you need help in getting the grinding done.)

Thanks to JBUK for the idea & data and Andy C & Ollie for the donor 'box.

Mike E

OwenS · Post by **OwenS** » Tue Sep 06, 2005 8:49 pm

Im tempted by the noise killer soundproofing idea. Could fit it at same time I strip out car for rust proofing.

BX Club Forum

Soundproofing

Soundproofing

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noise reduction

Changing 5th gear