SuperFinn asked me the other day about sound proofing a 2cv, and I had done a bit of this a while ago following on from my friend Julian soundproofing his dyane.

Then thought that this may be of interest to others so I'd post here.

I got hold of some fireproof sound deadening material from an auto factors place, it was kind of like a thick carpet / matting material about 1cm thick. Pretty cheap and you can still get it in general motor stores.

Julian told me that soundproofing material should be attached to panels, not necessarily to a whole panel, but even attaching partly to a panel will stop it resonating and therefore reduce the noise.

So if you've ever taken a door card off a 2cv you'll see there are three vertical rectangular shapes first step is to fill these in with cut out shapes of your sound deadening stuff, spray adhesive works well. You can do the same with the back doors and using three triangle shapes for the bootlid.

You can add the stuff under the front floor mat but I'd only do this if I was absolutely sure there are going to be no rainwater leaks as soundproofing material wet would be a fantastic rust incubator. Under the rear floor mat and under seats should be OK though.

The bulkhead is pretty well covered with soundproofing already, as is the inside of the bonnet (unless you are SuperFinn!) as those are the best areas to reduce noise.

The other areas I soundproofed were the inner front wings and triangles as you can see. The cut out shapes are really just to reduce the resonance in these panels rather than physically block the sound.






Once the whole lot is installed the difference can be quite marked, the next steps would be rear box section and inner rear wings, and depending on inclincation, replacing whatever is left of the headlining with soundproofing stuff too if you can find some which looks nice.

Or just ignore all of this, rip out the existing stuff under the bonnet and disconnect the crossbox for More Noise

I'm all for soundproofing. The factory under bonnet stuff from my car had been binned by a previous owner, and on long drives the 'rorty' sound of the engine began to annoy me.

I bought some of that stuff you have there and fitted it under the bonnet, in the triangle bits as you show, and on the bulkhead itself.
The difference was great! Much quieter, and better for long trips. It was only after stripping the car down that I noticed a hole in my 'swan neck' exhaust connector pipe that wasn't visible from above, so that was the source of the rortiness! I should imagine the soundproofing would be twice as good with a decent exhaust fitted.

I just love the sound of boxer. Wind and tyres If i want silent car, i would not drive 2cv...

I'll have to give this a try. Had to remove all the bulkhead soundpoofing when the shell went in for shotblasting so with nothing whatsoever between me and the enfine (except paint and a thin bit of metal) it can get a bit loud in the 4x4!