Renault 4 Soundproofing

[malcolm]

I've been messing around with soundproofing on the Gordini. The latest experiment was putting heavy layer and foam on the cabin side of the bulkhead (the most important treatment in modern cars, but missing on the Renault 4). I've used a rubber floor mat spaced off the bulkhead by 12mm foam.

Soundproofing on the bulkhead transforms the car! The noise from the engine is quite a broad spectrum so you don't really realise how much there is until you take your foot off the throttle and press the clutch in at 70mph. On the Gordini the soundproofing vastly reduced the level of that noise and surprisingly it also got rid of a couple of annoying booms.

The only other thing that seems to make a difference (but the effect is not all that noticeable until the bulkhead has been treated) is foam under all the existing foam mats. This is the other major bit of soundproofing modern cars have, and is an easy modification to make to the R4.

There's a little detail on http://www.renault4.co.uk/gordini-soundproofing.htm and notes about a couple of other things I've built in. (note vans have their own set of issues so might not benefit so much.)

Makes the car so much nicer up to 50mph (after that I still have a problem with wind noise, but I plan to crack that).

 

[snes]

If I want a quiet, civilised, all mod cons drive, I get in my Clio.

If I get in my R4, I expect engine noise, wind chill, whatever. Isnt that why we love them?

I dont want to sanitise my R4!

 

[Steve Hennessey]

Nice job Malcolm. So, next time I am a passenger in your car I can hear you talking - saves all that sign language and you taking your hands off the steering wheel!!!

As you have used material that will melt, have you put any heat sheild on the manifold as I remember things were rather hot in that area on the inside?

 

[nicky4tl]

Am looking forward to being at the stage where i can be making these modifications myself.
Interestingly when i got my tl i lifted the mat to find a thick layer of some crazy black stuff. It was like horse hair and black brittle plastic mixed up. I guess it was a sound proofing.

I pulled it all out as it was wet and sure enough water had started eating the floor in a few spots.

Was this stuff standard issue at some point i wonder?

 

[malcolm]

The horse hair and tar was fitted by Renault - it's a damping material. I tend to remove it to paint the floors to stop them from rusting. I'm not convinced it is the best solution - I haven't put any damping on the floor of my car.

The foam on the bulkhead keeps the car much cooler and I'd forgotten about the hot exhaust. I think there is some stuff at work I might be allowed to have to go on the engine side of the bulkhead to keep the heat out.

Each to their own whether it's worth doing any sound proofing. I put it in mostly to reduce noise on motorways over long distances. I also prefer the sound quality with it in for general driving about.