Soundproofing

[Steve A]

As most of my car panels have been replaced would you replace the soundproofing and if so how and what with? regards Steve

[JC T ONE]

I have put the thick (6mm) Black selfadhesive asphalt on all 4 floor boards, and the thinner version (2mm) on the door skin - under bonnet & rearquarters.
If you heat it, with a hot airgun, will it mould perfectly, with the creases in the floor boards.
The bonnet is then covered with this thick Brown felt type, with Black surface on the side thats visible, when fitted.
This type is also used behind & under the rearseat.
Behind the dash did I put some of the thin asphalt, with self adhesive foam on top.
You can also do the boot, if you want.
I dont know what car you do this to? but if its a MK I / II ? then cut a long piece of foam, and roll it up, so it fits inside the heater tube,
this alone makes a big difference.
On MK III,s & Clubman type, can you do the same, plus a slimmer version for the fresh air vent hose in passengerside.

Jens Christian

PS - make 100% shure, that you have closed ALL holes & cracks in the bulkhead, before you start,
use a big bright lamp, from both sides of the bulkhead, in a dark garage, as one small gap is enough for the noise to get in.

[Steve A]

Thanks, its a mk1, regards Steve

[JC T ONE]

Thanks, its a mk1, regards Steve

Happy to share some info

If its a MK I, and it has the later plastic type airhose, is the first step to a more "silent" Mini, to insulate the inner of the tube,
as it acts like a "speaker" becourse its so stiff, plus its very thin,
which means the engine noise, is much more apparent, inside the cabin.
The older type, made from rubber, were much better to keep the engine sound, away from the cabin
These can ofcourse also be insulated, to make it even more quiet

Jens Christian

[Chris64]

Hi Jens,

Some great tips thanks for sharing!

I need to put some grommits in a couple of holes in the bulkhead as you suggest, but I'm intrigued about your suggestion for the heater hose!

So are you suggesting rolling up some foam to fit the whole length of the tube - right to the heater? How do you get it in without it getting caught and blocking up the tube?

What sort of thickness would you use? I guess you don't want it too thick that it would cut down on the flow of the air significantly?

Cheers,

Chris

[JC T ONE]

Hi Chris,

you are spot on but it only need to go through the bulkhead, and a bit into the cabin.
I know the tube on a MK I can be very "curled up" so when you have cut a long piece of foam,
then spray it with glue - roll it up, and push it into the tube, and let it settle firmly.
Then fit, after the glue is dry, this way it wont curl up, and block the tube.
You can use upto 20mm, without blocking the air way too much.

Those grommets, really do make a LOT of difference, thats why I suggest the use of a bright light,
as its so easy to miss a small gap, where a wire/hose/cable, goes through the bulkhead.
One small gap, and the encrease in noise, is significant.

Also make shure to insulate the hollow crossmember, that master brake & clutch cylenders is boltet onto,
there are directly access to the cabin, from the pedal area, and heater hose plate, so this part, can also be targeted VERY efficient.


Jens Christian

[Chris64]

Great thanks Jens - I need to replace my heater hose so I might give this a try with the new one! And good idea about under the master cylinders.

My two year old daughter loves riding in the Mini and recently she's taken to saying 'Mini very noisy Daddy!' (with a big smile on her face though!) so I thought I'd better look into quietening it down a bit more.

Cheers,

Chris

[JC T ONE]

Hi Chris64



That crossmember is something a lot of people seem to forget (me too)

but it really is a noise amplifier as its bare & hollow metal, in direct contact with the cabin
on some cars, you will find holes, for clips & other stuff.
People dont think it matters, as its "not in direct contact with the cabin" but IT IS, thats why you can gain a lot, from attacking this area.

One of the most common faults, is when the blanking rubbers, for where the hydro hoses, use to be, are missing.

I would have loved to cover the engineside of my baulkhead too, but I dont want to risk anything catching fire, becourse of the Turbo.

I forgot to mention the parcel shelf, this can also be covered, with both the Black asphalt plates, and some felt on top (and under) Wood & Pickett did both.

The inside of the bootlid can also be done, if its a doubbel skin ? you can get a carpet made, with beading around the edge, this makes a big difference too.

If you do all of the above, you will feel a big difference, it really transfers the Mini into a "bigger" car expirience
thats why Radford and W&P did most of these things.

Jens Christian

[Steve A]

Thanks for the tips. I don't want to go to far with the soundproofing as afterall its a mini and not meant to be too quiet lol. Its just things like the doorskins and rear quarters have been replaced and i seem to recall there was a sort of matting glued to them like i still have inside the roof? thanks again Steve

[JC T ONE]

i seem to recall there was a sort of matting glued to them like i still have inside the roof?

Hi Steve,

yes thats the Black "asphalt" type I mentioned, it stops the plates from sounding like a hollow oildrum

Every larger bare plate in/on the body, will benefit from being covered with some of this stuff.
It dont need to be "all over" just a fair size in the middle, and it will stop the "empty oil drum" effect.
Thin type on doors/quarters/etc, and thick plates on floors.
This is why the SPI / MPI, s are so quiet, compared with a old Mini.

Jens Christian