What's this black stuff under the carpets?

[Joss Walker]

is it original, what does it do and do I need it?

I've got my carpets out and it would seem that a PO glued them back in with all the glue they could find, this has adhered really well to some kind of thick black rubber like layer on the floor that has now dried and cracked into little pieces. is this a soundproofing measure of some kind of internal waterproofing because mine is a cab? It seems to be in the rear footwells only, the front footwell has a nice padded foam layer and there is nothing at all under the seat. the rubber like coating on the transmission tunnel has also deteriorated under the added influence of a PO's stanley knife. On a plus side I am finding a lot of my missing screws and loads of speaker wire.

 

[CarreraRSR]

Sound deadening sheets of tar by the sounds of it, now attacked with solvents?! You would have had a thick foam layer in front and rear footwells and the tar under this again.

Two choices. Leave it all alone and forget about it or remove it all. Makes the car lighter but considerably noisier. If you don't like the fact its all a bit messy under the carpet you could remove with a heat gun and replace with Dynomat or similar. Does a better sound deadening job with far less weight and will look nice and clean under the carpet.

I just removed mine in search of weight saving.

 

[Paul 290T]

I concur with CarreraRSR,

These are bitumen pads inserted after the electrocoat paint process, but before the surfacer or topcoat paint is applied. The oven stoving process after the subsequent paint application melts the bitumen which adheres completely to the bodyshell to act as vibration damping.

 

[Joss Walker]

Thanks guys, the melted bitumen comment makes perfect sense now, my interior doesn't look quite as clear as Carrera RSR (my exterior won't be a patch on yours either!) I've ordered my Dynamat and will be out there with the heat gun tomorrow!

 

[Neil Haughey]

As above. If yours is anything like my S2 was some of it would have gone pretty hard by now. Underneath the carpet you basically have sections of rubber backed foam which is fairly easy to remove and underneath that you have this horrid stuff to stop the panels vibrating. Personally I would leave it alone unless one is building a race car. Fair amount of weight in the rubber backed foam though especially the very thick sections they put up in the foot well/bulkhead, which luckily is also the easiest to remove.