I'm finally getting round to sorting out the interior of my 5spd. I had never put things back properly after I had to strip the interior to find and fix water leaks.

Most of the original sound insulation had been degraded by the water or simple old age - the foam and rubber was crumbly and the mastic panels had lost all their elasticity - so out it all came.

I have lined the rear with "Brown Bread" sound deadening material which is a couple of mm thick mastic sheet backed with aluminium foil. When it is slightly warm it sticks really well and with a bit of rubbing/rolling forms easily to the panels shape.

<img src="http://homepage.mac.com/potw/.Pictures/char%20grilled/silver.jpg" alt=" - " />

The next thing was to fit a new rubber membrane for the rear seat buckets. This has to be the most unusual spare part I have bought to date. Fitting it in place was a bit like wrestling an octopus! I'm going to leave it sitting in place for a day or two to relax back into it's proper shape before I glue it down.

<img src="http://homepage.mac.com/potw/.Pictures/char%20grilled/membrane.jpg" alt=" - " />

The next thing will be to fit the full carpet set which should turn up in about a weeks time. I ordered it from Southbound Trimmers in the UK. Following that I'm fitting the all dark blue interior from my auto, which is already removed, cleaned and waiting. Looks like a busy few weekends coming up.

Cheers
Dave

 

Wow Dave and I thought I did a lot. I am sure that kind of improvement would register on a decibal meter . Let us know how you like it.

 

Dave,

What is "Brown Bread" for sound control ?

Where do you get it?

Thanks
Richard

 

Jerry, Yeah I know... It has got a bit out of hand! and I have the front of the car, the doors and roof panel to do yet! To start with I only bought a small quantity to replace the panels in the rear seat buckets but three things made me decide to go further:

1) the car was already stripped so it was easy to do, I don't see me getting this deep in again once the new interior/carpets are in.

2) I was worried about adding weight but in comparison with other interior components like the seats and that new rubber insulation panel (sooo heavy) it's not too big addition - I would guess 5kg for a full interior.

3) I've finally decided on new roles for my two 928's. The current 5spd is going to be my sensible everyday car <img border="0" alt="[ouch]" title="" src="graemlins/c.gif" /> , so a bit of sound insulation for a quiet life is a good thing. While my auto (which I haven't used much recently) is going to be stripped and tweaked for a trackday car (A long term project with maybe a 5spd conversion along the way!) for me to have a bit of fun in.

Richard, "Brown Bread" is just the trade name for one makers version of this kind of mastic sheet. I chose this one partly from recommendation through Rennlist (step forward Jerry!) and partly because it came out top in a couple of magazine tests I read - MaxPower and someplace else. I bought it from here:

<a href="http://www.caraudiodirect.co.uk/shop/acatalog/CAD_Sound_Deadening_152.html" target="_blank">car audio direct (in the UK)</a>

In the US you can get it here:

<a href="http://www.b-quiet.com/" target="_blank">http://www.b-quiet.com/</a>

Cheers
Dave

 

Dave,

That looks really good. I was thinking of doing the same thing in my S4. I would like to strip the rear (take out the rear seats) interior, go the sound deadening material route and then overcoat the entire area with something like "Wurth Undercoating" to give it a nice complete satin black look. I would then like to install a DEVEK rollbar with possibly a harness and new seats. I am interested in making the car as quiet as possible (no rattles, etc.) and since I don't really listen to the radio too much, maybe just replace the front speakers with some newer cleaner sounding units. I have never even heard of that rubber insulation panel you were speaking of.

Rob

 

DaveW - thanks for the pics!

Thats exactly my plan soon, except I am going to just put silverknit carpet over the fender wells/back seat area over the Brown Bread.

How/did you remove the original tar panels?

Where did you get the (heavy) rubber membrane, from zee germans or aftermarket?

 

Dave -

What's the rubber membrane for? More sound deadening in addition to the BrownBread?

 

Dave:

I think it was a good idea to start sound deadening in the rear, as this is where most of the road noise in the 928 comes from. That's why from '91 on, they added padded fender liners and heavier foam for many sound deadening areas. Don't forget the floor under the carpets!

 

Dave. That looks great! (like something from NASA). The difference inside you hear (or I should say dont-hear will be outstanding).

Bob

 

Nicole is SOOOO right. I've driven 3 928. My 88, an 89 GT and a 91GT. The 91 I drove was a very different experience. In fact, I'd say that for some people it might be too "refined". These are the same people who like the heavy clutches and steering of the older cars though.

I think a 91 is worth a premium over a 90 IMO.

 

Dave:

What source did you use for the instructions for the removal of the interior rear quarter panels?? I'd like to remove them myself.

Seth

 

Thanks for the interest guys'n'gals, I will post more pics as work progresses but I can't go much further until I receive my carpet set. It would be good if anyone can suggest a source of the foam insulation sheet used under the front carpets and the deck carpet. I haven't found

Robert, That's a nice idea of using silverknit to line the rear of the car. I was thinking of using vinyl on my auto when I get to work on it.

Porken, the tar panels were quite easy to remove with a stiff scraper as they had become quite hard and brittle with age. The difficult thing to remove was the old glue residue. The porsche assembly guys used this stuff everywhere and in quantity. Unfortunately age and water has made it slimy and like chewing gum. I scraped/picked as much off as I could and then used petrol as a solvent to wipe off the rest. I did this outside on a windy day with two extinguishers to hand! Once on fire is enough for this car!

Seth, for instructions I used the PET CD. This is the kind of thing that's not really covered in the manuals but the PET shows you what type of fixings are used and where they are, so it's easier to understand how things come apart. The PET is also useful to figure out what parts you need to put it all back as a lot of the plastic clips need replaced.

Cheers
Dave

 

You could always do the doors, I noticed a major improvement here as it was the first area I did.

I also did along the console in the front.

 

Yup, I could do the doors, In fact gosh-durn it I will. I was delaying as I was thinking that I should replace the rubber window scrapers (not ordered yet) while in there. But the doors are easy enough to re-access so I should just get on with it - one thing at a time.

Cheers
Dave

 

Dave,

Actually, it was Porken's (Ken ?) idea to use the silverknit carpeting. I was just going to use the underseal as the final treatment (kind of a more refined race look), but to have it fully carpeted and still open (for me... no rear seats or side panels), yet have the carpet and rollbar installed is very tempting.

Rob