Sound Deadening.

[Mr Gus]

Just been shopping to keep Big Red ticking over & the sound deadening material on the Brabus makes one heck of a difference to cabin noise / engine noise between it & Krteck (the other 450).

Not having the same tyres, nor having an actual list in the worksheet of what has been done (other than billed for it as sound deadening) its hard to find out & compare what / where has been done beyond the obvious engine access hatch.

Therefore am looking to folk as to 450 experience of how much sound drop off comes from deadening the hatch (I can take it off & weigh it to get a vague idea of quantity if it gives insight) because the two cars are chalk & cheese db wise, ..what brand should I fit for a quick fix to make a start on tweaking the sound on the basic "standard" 450 ?

Also, any maintenance downside from removing wheel arch panels & fitting deadening materials there?

Cheers

[Mr Gus]

Having read on Smart car forum (& a post by Tolsen there) it appears the noise from the engines should be the same (which is as I thought based on design, space (voids) engine size etc.

My locking screw is ok, the rubber sits tight on both cars but the noise on krteck is quite something.

With not much actual knowledge & dissemination out there (but plenty of marketing) I'm going to buy 9 folded squares of the Noico Butylbased with AluFoil
(Thickness: 80mil=0.08in=2mm)
Sheet size: 19.5x15 inch (50x38 cm) To cover the boot engine area & down the hump (rear wheel curvature in the cabin, to see what difference that makes, I ought lift the carpets & see if the Brabus has any more than the engine cover (at least visible) ..however I do know there isn't any in the front of Big Red.

Thus the question of how much (& where) produces what amount of noise suppression?

[Mr Gus]

Changed my mind re the product, I only want to do this once, so am now looking at 4mm version from Silent Coat rather than finding one is quiet & the other is quiet-ish.

I think the boot area is small enough to warrant it, what are opinions as to over the rear arches plastic trim voids (inside)?

Bit the bullet & ordered the 12 sheet pack this morning in order to check out the realistic coverage on either car.

There is a 10% discount code I can supply for anyone who is thinking of using their product via the sound deadening website (compared to the sales on ebay amazon et al).

Have been impressed with the pre-existing (same brand) stuff on the engine hatch as we have not experienced whiffs from it (something that is often mentioned) it is butyl based not bitumen which I'm "guessing" makes the difference.

Will grab a bottle of 151 (poundshop) de-greasant & prep the area when it arrives.

[Mr Gus]

Tackled it today, a mere hour to do (warm weather the sheets were in the car for a few days nice & warm, easy to line up & cut then cover the joins with aluminium tape I use for phenolic insulation.

Will go for a drive tomorrow & see what difference is made, as to whether part of it is the posh tyres vs standard (critical appraisal) that help in part, or not.

For reference though 4 tiles of this brand will do the hatch with a 1/4 sheet sliver left over (thus 3 & 3/4 sq feet used of 4 square feet)

Easy to cut, I used a new blade in a stanley knife.
crosshatch guidelines are on the back of the adhesive paper.
A score cut followed by a separating cut sufficed.

I took the engine cover out, took it inside & placed it on a crafting table with scrap wood for the score line, so no drama from the family.

Generic seam rollers are available in various sizes, mine was the smallest size available & cost around £6.50 ..I recommend "small" which has a 1.2 - 1.3 inch width (roller head) due to the raised areas in the pressed metal engine cover, bigger would have been restrictive, as was it enabled me to finger push into the outer creases then press it home due to the roller being able to nestle in the space, it saved hassle rather than creating it.

This leaves me a further 8 & a bit to work out whether I can safely place this under the wiring loom I found where the rear wheel arch rolls downward toward the seats, "likely" 4 per vehicle, after assessment.

[Mr Gus]

Had a drive today..

Results are in.

Completely worth the (minimal) effort.

Will now use a few leftover bits to plug in the big old gaps that the "professionals" left out on Big Red rather than have it go to waste.


The cabin noise has gone from noisy & the radio (speech) turned up to at least 26 on the standard grundig to 18 & perfectly legible on a variety of road surfaces & speeds (backed off at 80 mph on a country road) ...could also hear the turbo note more clearly.

Far more relaxing ride that made even the speed bumps a non issue due to far less tense up moments by comparison.

The basic 4 pack will do making it a cheap interior mod, i'm still needing to see if it is possible without ripping out seats to cover some more near the engine for a bit more of a result.