8 replies to this topic

[miniJJ]

Hello.

I have searched through all of the sound deadening topics, but I still have some questions I'd like clearing up. Basically, my mini is VERY loud inside; it's not much fun driving it like this. I want to add sound deadening to kill engine / exhaust noise on the inside, not to improve my music quality. I need some advice.

1. I need to replace the insulation on the bulkhead / firewall / dash area, as half of it has been removed due to it holding dampness. (which will now be causing part of the noise issue) What is the best stuff to replace this with? (original or aftermarket?)

2. Where are the key areas on the mini which benefit from more sound deadening? The floors still have the original bitumen stuff on, but there is no felt layer betwean that and the carpet.

3. What to use? I've looked at dynamat etc, but this doesn't look to be cost effective for me. I'm not looking for something to improve music quality, just block engine / exhaust / road noise. Some people suggest a couple of layers of flashing tape, but others say it's useless. Any advice as to a reasonably priced sound deadener?

I know this is partly down to my spec: (998, k&n cone filter, cooper freeflow manifold, rc40 straight through 1.75 exhaust, no silencer, megajolt ignition, solid subframe mounts) but this is all staying (would subframe mounts effect the noise that much?), as the car sounds nice from the outside, and performs well.

Thanks for reading,

JJ

[Retro_10s]

* Ditch the cone filter for a K&N element in a standard housing, It's quiter and proven to perform.
* Flashing tape can be applied over the entire floor area+inner arches- is MUCH cheaper than Dynamat + does the same job.
* Bulkhead sound proofing felt (search minispares) is good for blocking engine noise.
* Cloud 9 Foam insulation,.. go to a carpet store and buy some off the roll, it's cheaper than a kit specifically made and better.
* Solid subframe mounts are very noisy compared to Rubber ones.
* Twin box Exhaust system rather than a single box makes a huge difference.

[bert998]

Ive lined my entire car with 1 1/2 inch thick densely bonded foam, including the boot and the roof. It should make the car a lot better to live with, not so sure the 998s going to like it though

[miniJJ]

Thanks for the infomation mate!

I'm looking to keep the k&n cone and exhaust as it is, because it was fitted by the previous owner not long ago.

So, plan of action:

*Flashing tape on bulkhead, floors and arches
*cloud9 insulation betwean tape and carpet
*felt insulation on bulkhead
*maybe rubber / soft poly mounts on subframe?

Thanks,

JJ

[miniJJ]

Yeah, don't want to add too much weight if I can help it! But I do need to sort these noise levels out.

JJ

[Jonny998cc]

are solid subframe mounts really that much louder?

[Retro_10s]

Yes.

Rubber mounts absorb the noise that gets transferred through the subframe - noise from the suspension, and road noise etc. Solid mounts simply transfer the vibrations that absorb them.

Think of it like comparing two people jumping on a large trampoline, one has the normal springy mesh on it, the other has a solid sheet of metal instead.... noisy methinks (messy too i imagine!)

[Brams96]

I used solid rear and tower mounts and rubber teardrops without any noticable increase in noise levels & thats with a Kn'N filter and stainless RC40. The roof reverberates a lot of noise so maybe try and do something with that as well as the bulkhead.

[rasputin22]

I put a 1 foot by 3 foot piece of sound deadening on the underside of my roof instead of the hardly stuck on felt that was OE. This has made alot of difference, but next time i would use a 2 by 3 foot one as it still reverberates a little bit and would cover the majority of the roof.

It was only cheap stuff off ebay and was self adhevsive and had a foil coating (ebay member cheap_at_half_price). Planning on putting some on the engine side of my bulkhead soon too and maybe the inside of the door panels. It was only £5 for the 1 x 3 foot plus a £2.50 postage and it gets cheaper as you by more. Cheap, cheerful and did the job.