Sound deadening a 306

[Niall]

This is a guide I'm going to be writing over the coming weeks as i finish it off.

About sound deadening
Most people think that sound deadening such as dynamat absorbs sound waves and pressure and as such means panels dont rattle. This is true but not entirely.
The main difference is made by 'weighting' the panels. Taking a car door for example, the outer skin of the door is no more than 2mm thick on most cars. When you consider that you probably have about a square metre of area on the front doors of a 3dr 306 with no real support in the middle, it's going to mimic the cone of the speaker to a small extent. This causes rattles!
The idea behind weighting panels with bitumen sound deadening is that it adds dead weight to the panels meaning the air pressure created by the speaker in the enclosed space (door) is not enough to reverberate against the panel.
Not only does sound deadening give good sound proofing properties but it also helps with keeping warmth in, in the winter, heat out in the summer and also helps to reduce road noise. What it DOESN'T help with is weight! Bitumen is a heavy material and as such, if you plan on doing the entire car, you will probably be adding around 15-20kg to the weight. The other downside is its expensive! To do the entire cabin of a 306, you will be looking at about 160 quids worth of silent coat (a cheaper but just as good version of dynamat).

There is a way around this though! Areas such as the boot floor, floor of the car etc don't really require bitumen sound deadening (unless you are going for a very expensive SQ build). These areas are generally thicker metal but are also shaped (instead of being one flat sheet of steel). This means these areas don't really suffer from rattles however they do let a lot of road noise in which most people don't realise, makes a huge difference to SQ. Peugeot have put sound deadening material on these areas but it's cheap, heavy and doesn't really do much other than soak up water and go moldy.

This is where cloud 9 comes in!
Cloud 9 is a carpet underlay with a difference. Unlike most underlays it's sound proofed to a rating of 45Db. It's also made out of PU foam instead of the traditional rubber carpet underlay you may find in your house. The benefits of cloud 9 are it's very light, very versatile, great for sound deadening and a lot cheaper then bitumen sound deadening (I've just payed 69 quid for a roll of 15sq metres. Enough to do 2 cars!). The only downside is its chunky. They offer 2 thicknesses, 7mm and 9mm. Both are rated to 45Db so there is no performance difference. Only difference is feel underfoot which isn't a problem for us unless that bothers you in your car!

Throughout this guide I will be using a mixture of cloud 9 and silent coat to get the best of weight saving, sound deadening and money saving!

[Niall]

Boot floor

First and easiest area is the boot floor. For this I'm using cloud 9 because to silent coat it, would use a fair amount and add a fair bit of weight.

Start by removing your old carpet and sound deadening. This is held down by 4 pegs pushed into the floor. These simply prise out. Keep the carpet and chuck the sound deadening (notice how much weight is in the sound deadening?)

Take your carpet and lye it on top of a section of cloud 9. Take some sharp scissors and cut around. It's as simple as that!



Note: I have been informed by my carpet shop that the paper side should be up as it offers a slight degree of water repellent.

Next, take a few strips and some spray glue and start filling in the gaps in the boot floor. Gluing down each bit. This doesn't have to be neat. It's only there to stop your carpet following the line of the floor and looking shitty.



Next simply take your cut to shape bit of cloud nine and rest on top. Don't glue it down as you might need access under here at some point. Place the original carpet over the top and pierce through where the pegs go. Place pegs through to hold it in place. Job done!

Just doing this has made a massive difference! Road noise has dropped a lot and the clunky rear suspension is now more of a thud!

Next: deadening doors.

[Ben]

I'll keep an eye on this thread for when you do the doors. Never even crossed my mind to try and block out some of the noise I've just got used to being deafened! Thanks for the idea, I might do the same at some point

[Niall]

Doors will be done saturday

[Matt]

I've the underlay in my boot going to replace all the stuff under my backseats soon too

[Niall]

I've the underlay in my boot going to replace all the stuff under my backseats soon too

What cloud 9?

I'm doing the entire floor. Hopefully do it Sunday if I don't get called out!

[Matt]

Urm nope just underlay lol. How much is cloud 9?

[Niall]

Urm nope just underlay lol. How much is cloud 9?

Normal underlay will do bugger all. Need at least PU underlay

I payed 2.99 a metre for mine on eBay but just bought a massive roll for mine and grants car for £69. Probs be enough do do 3 cars now I think about it lol

[Matt]

Lol whats the dimensions. You can do length of a meter but how wide?

[Niall]

Is sold by the square metre is about 1.3m wide roll

[Matt]

Ahh sweet Ill do some measurements and order some

[Jonny b]

You are going to add 15 to 20 kilos to your car!!! Are you mad I keep trying to find more ways to strip 20 kilos out ha ha

[Niall]

You are going to add 15 to 20 kilos to your car!!! Are you mad I keep trying to find more ways to strip 20 kilos out ha ha

Are you trying to spam every single one of my threads! Haha

This is the reason for using the cloud 9 in certain areas, and considering how much the pug stuff weighs, I think it will balance out nicely once all Swapped over

[Jonny b]

Gots to get me post count up somehow I was over 10 thousand over there!! Taken me over 6 years ha ha

[Niall]

Ahh sweet Ill do some measurements and order some

What are you thinking of doing? 3-4 square metres will do th entire floor pan with left over.

[Niall]

Gots to get me post count up somehow I was over 10 thousand over there!! Taken me over 6 years ha ha

Post whore!

[procta]

is it like a sponge? as i could do redoing the metro as rovers stuff is a weight and a half!

[Niall]

Yeah it is spongy.
I didn't weigh them but the bit I put in the boot was probably 2 or 3 times lighter than the pug crap that was already in there!
It's fantastic but obviously not very versatile for areas like inside doors or tight spaces.

[Harky]

Hmm, I could be tempted to look into this....but I'd worry about the weight.. I spend time and money trying to make the car go better, it might be a step back to add more weight..but a quieter cruiser would be nice too :-S

[Niall]

Have you still got the pug sound deadening in your car?

[Harky]

Yea, not something I've looked into before tbh. Phase 1 though, how much sound deadening is actually in there!

[Niall]

Fair bit. Rear quarters and under all th carpeting. Fair bit of weight!

[Harky]

So I could go lighter and quieter...guess its time i thought about budgeting it in!!

[Matt]

Ahh sweet Ill do some measurements and order some

What are you thinking of doing? 3-4 square metres will do th entire floor pan with left over.

Boot and under rear seats for now

[Niall]

Get 4 metres to be safe. Can use the left over in rear quarter and I between dooor cards and doors

[Grant]

You are going to add 15 to 20 kilos to your car!!! Are you mad I keep trying to find more ways to strip 20 kilos out ha ha

Have a turn out and cut your hair before you drive the thing then lol.

[Jonny b]

You are going to add 15 to 20 kilos to your car!!! Are you mad I keep trying to find more ways to strip 20 kilos out ha ha

Have a turn out and cut your hair before you drive the thing then lol.

ha ha you've seen my hair nowt left to cut as for the turnout iam very regular!!! gots to get lots of fiber at my age ha ha

[londondan86]

Looking good this. I just ripped out all the pug insulation last week when i changed the beam. It was disgusting, 17 years of mingingness lol! And it weighed about 7-8 kilos I would say.

So yea perfect timing as I haven't got anything in there at the moment so looking for alternatives.

[Ian]

No deadening needed. You have to listen to the stones etc pinging off the bottom of the car and all the little rattles that you never knew you had. Or in my case a slightly "buzzing" rear box...

Now why did I strip my car again?

[Jonny b]

No deadening needed. You have to listen to the stones etc pinging off the bottom of the car and all the little rattles that you never knew you had. Or in my case a slightly "buzzing" rear box...

Now why did I strip my car again?

Because driving a stripped car is the best!!!