Material under carpets

Hi all,

I am stripping my car ('72 911) for a bare metal respray and have come across a number of parts that I am not sure about their purpose.

The items in question are in the rear seat/parcel shelf area. Under the seats and carpets there are these plastic/rubberized bucket looking things in the seat wells. In addition, on the sides of the same area under the trim there are sheets of a rubberized cloth (olive greenish in color). The third thing is a foam backed material under the rear shelf and behind the panel that would be behind the rear seatbacks when in their upright position.

I think they may (must) be sound deadeners, but I am wondering if they have a different purpose and are necessary. The car will be a street car, not a race car. All of these materials are quite heavy, so if this was going to be a race car I'd say "see ya" to these pieces. Since it isn't going to be a race car I am trying to decide if I want to re-fit them.

I am assuming they are there to protect the driver/passenger from heat and noise from the engine and transmission area. Has anyone here removed all this stuff, and if so, what are the noise and heat implications? Also is there another purpose for these pieces?

Thanks again,
Charlie

PS. I discovered that one of the PO had replaced the driver's side quarter panel at some point. During my previous inspections of the car I noticed that the inside of that rear quarter was the only rusty part on the tub. Now I know why! It looks like I am going to have to replace the whole quarter panel to get the car back into top form.

hey there!

yes! i have just removed all that crap in my 924 and it was very interesting. if you need tips on how to do this, e-mail me and i will tell you how. i would not mind posting how to do this on the site, but this would turn into a HUGE and long thread. also, i check my e-mail more than i check this site because i am at my computer all day.

check out my pics of my project. mine is a bit rough because it will only end up being a car for the track.

http://209.150.235.158:8585/924project/

also, by guaging the time on the photographs, you can see how long it took to do the entire project by myslef with only a tiny bit of help.

obin

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A straight line is the most BORING distance between two points.

one more thing i forgot to note:

if you are going for a bare metal respray, then remove all of the insulation. put new insulation in it's place, like Dynamat (or equivalent). the new insulation is MUCH better than the factory original and it is also lighter. before you put the new insulation in though... drive the car around with only the driver's seat in it. see if it's too loud for your liking. you may be surprised at how much LIGHTER your car is, but it's not that much louder.

obin

Thanks Obin,

I actually pulled it all out last night. The only thing inside the car is the dash with guages, the steering wheel and the foam that is above the headliner. That will all be coming off soon too. I'm just trying to decide if it should go back in.

Since my car is so old the adhesive that held everything down was pretty weak. It made disassembly go very easily. Reassembly may be a different story...

Having the car apart reminded me of my rally car. When I took it apart I didn't have to be cautious at all since nothing was going back in (except the dash). It made me want to turn the 911 into a race car too. But I bought the 911 and sold my rally car because racing is far too expensive of a hobby.

Driver's schools are a different story though...

Thanks,
Charlie

Hello

The sound insulation from the rear shelf is NLA and even if you not put it back in again keep them for a later 100 pt restoration.

Heat transfer is only at the trany hub. Noise change is significant in level and frequency. So save an other pound by deleting any Stereo equipment and use the right pedal as volume control and the gaer lever as station selector.......RS lightwigts sound.......6 throttle flaps snorkeling
Race driver have helmets or ear plugs...

Grüsse

So..would the material under the carpet in other areas, say, passenger footwell on the floor pan be insulation, and if I didn't give a damn about sound and concours, I could just rip it out? Thanks!

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Jeff
1976 911S

point of reference:

a lot of our Porsche "dream cars" didn't have sound insulation (924 Carrera GT, 959, etc)

i also don't have any insulation in the back of my VW Scirocco 16V and it doesn't bother me at all.

obin

Roland,

I really like the way you put that. The sound of the Porsche engine will be beautiful of music to my ears.

The good point is, if I save all of the parts I remove I can always put them back in if I decide it needs more sound insulation.

Jeff, I do not see why you couldn't remove it. The tar-like sound deadening is very heavy. However, it is also a pain in the neck to remove if you do a thorough job. See Obin's pictures to get an idea of the effort. Removing it is hot/dirty/stinky work involving heat, scrapers, and various solvents.

The only side effects of removing all of the insulation that I noticed on my rally car ('92 VW GTI) were increased noise and heat. The noise was both engine/transaxle noise and road noise. The road noise was probably worse than most street cars would experiencing because of rocks and gravel pelting the bottom of the car on stage. Heat was only a big factor in the dead middle of summer if you are not moving much (like waiting for a stage to start at the Maine Forest rally). The heat may be over exaggerated because we had to wear racing firesuits and helmets that really hold in body heat.

You probably wouldn't have that problem on the street, but you might notice a difference in cabin temps if you are in city type traffic without much airflow.

Thanks,
Charlie

Thanks Charlie. I will take a look at Obin's site. I've wondered what that was ever since I ripped all the carpet out when I first bought it. Thanks again (oh and also thanks for the welding answers).

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Jeff
1976 911S

Hello

I don´t like to rip out something as this word RIP descripes mostly the end from such things.

Right now you might think those parts are useless and destroy them to get "rid" off it.

If you chance your mind in some years you will have to find that same part and search for many money.

So better remove the things like you where unpacking a "Christo" parcel and store the things. Even if you don´t need them in future you still can sale them to people who need them desperatly.

Sme things like the 30$ squre meter Terson soundinsulation is not worth spending to much time.

The fastest way to get rid off the tar and PVC things is to cool them down with liquide Nitrogen. Then just slight hammering will kick it off.

All Porsche cars even 959, 911 RSR, 931 GT and so an had minimal Sounddeadening. Only Racecars came without it. Racecars also had deletet seam sealing.

The 959 is a very quite car inside and out.

I had a thread about sonddeadening and basics for that on the 911 Rennlist board. Just browse the archiv.

Grüsse

People talk about using dry ice and now even nitrogen--cool! (no pun)--to remove the hardened-tar floorpan insulation, but it took me an hour of work with a puttyknife to get it 100-percent out of an '83 SC. It's not a big deal; once you get a "corner" up, it keeps going and going and going...

Stephan

Hello

I do know and some slight heat will speed up there.

Wait until you have to remove the things on the underside of the pan.

If you have to much to do to pack it in a working day you must find a way to save time. Costs aren´t interessting then. Better 2-4 concentradet hours then 2-4 work days in dust and dirt. Other do hot tank or use plastic blasting. Both ways have other benefits but you have to organize it and pay the company. And mostly after that you still have to sandblast the rust away.

Read all about the noisy and loud 959, the prototypes had been so loud that you even couldn´t hear the engine ideling inside, so after Karajan complied about missing some music they made the cars a bit noisier: http://www.911turbo.com/turboclub/history/history.html

Grüsse