hi guys, just wondering if the vents in the rear fastback pillar are really needed.
i have an early one, and it doesnt have them, but my later one does.
just seems like another place to let water in and rust (again)



cheers
Muz

It's the same deal with late bugs which have the same system.

The world won't end if you fill them and early cars survive without them but they were added for a reason.
They have a pretty good built in drain when its not blocked so water isn't a problem

VWs were always very air tight when new so when you start adding outside air into the cabin with the windows shut by turning on the heaters or the fresh air fan you pressurise the cabin.

Those vents extract air back out of the cabin so the heater and fresh air fan works alot better and also lets the doors shut alot easier if the windows are up.

VW just stuffed up by filling the cavity around them with expanding foam.

ok cool, thanks Joel
yeah i noticed the dreaded expanda foam there, while
cutting a couple of bits of rust out.

easier to leave them and treat them with rust preventer.

Thank you

foam was for structural reinforcement i believe.

but this became a double edge sword as it eventually compromised the integrity by rusting out.

Nah it's just to keep noise, dust and fumes out of the cab.

They were using padded pillows made of headliner scraps before that for the same purpose before the foam

As one of my mrs friends said, and I am quoting what she said. She had an L Bug with the expanding foam

You get a coat hanger and make it into a long hook. Get into the engine bay and get up into the pillars with the coat hanger and give it an abortion.

those look neat... IMHO

not sure whether fastbacks had the same problem as beetles??

as the engine is actually under the car... NOT in an engine bay
like a beetle..

You can buy waterproof expanding foam these days too...

LEE

Quote:

Originally posted by vlad01 foam was for structural reinforcement i believe. but this became a double edge sword as it eventually compromised the integrity by rusting out.

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Originally posted by torana hi guys, just wondering if the vents in the rear fastback pillar are really needed. i have an early one, and it doesnt have them, but my later one does. just seems like another place to let water in and rust (again) cheers Muz

Quote:

Originally posted by L469 Quote: Originally posted by vlad01 foam was for structural reinforcement i believe. but this became a double edge sword as it eventually compromised the integrity by rusting out. it was used to prevent noise and fumes entering the cabin the later not mentioned by vw because they didnt want to draw peoples attention to fumes in the cabin.the structural benefits are very small if any at all . because it compromises the crumple zones having it in a cavity think about it!

Quote:

Originally posted by vlad01 Quote: Originally posted by L469 Quote: Originally posted by vlad01 foam was for structural reinforcement i believe. but this became a double edge sword as it eventually compromised the integrity by rusting out. it was used to prevent noise and fumes entering the cabin the later not mentioned by vw because they didnt want to draw peoples attention to fumes in the cabin.the structural benefits are very small if any at all . because it compromises the crumple zones having it in a cavity think about it! its the main pillars that supports the roof area, useful if you roll the car, not really a crumple zone.

Quote:

Originally posted by vlad01 Quote: Originally posted by L469 Quote: Originally posted by vlad01 foam was for structural reinforcement i believe. but this became a double edge sword as it eventually compromised the integrity by rusting out. it was used to prevent noise and fumes entering the cabin the later not mentioned by vw because they didnt want to draw peoples attention to fumes in the cabin.the structural benefits are very small if any at all . because it compromises the crumple zones having it in a cavity think about it! its the main pillars that supports the roof area, useful if you roll the car, not really a crumple zone.

Quote:

Originally posted by vlad01 Quote: Originally posted by Joel Nah it's just to keep noise, dust and fumes out of the cab. They were using padded pillows made of headliner scraps before that for the same purpose before the foam dust and fumes? nah, the foam is in a sealed cavity from where the vents are, noise maybe? but I can't see that even working considering in in the pillar No pretty sure its structural as it prevents the metal folding flat on impact, packed solid with foam in a sealed cavity is structurally strong but giving enough to absorb impact without needing to add weight with heaps of metal. I have seen it on many other cars and there was no apparent purpose except strengthening curial areas.

yes joel thanks for the common sense input.

Quote:

Originally posted by Joel Quote: Originally posted by vlad01 Quote: Originally posted by Joel Nah it's just to keep noise, dust and fumes out of the cab. They were using padded pillows made of headliner scraps before that for the same purpose before the foam dust and fumes? nah, the foam is in a sealed cavity from where the vents are, noise maybe? but I can't see that even working considering in in the pillar No pretty sure its structural as it prevents the metal folding flat on impact, packed solid with foam in a sealed cavity is structurally strong but giving enough to absorb impact without needing to add weight with heaps of metal. I have seen it on many other cars and there was no apparent purpose except strengthening curial areas. That foam has about as much structural strength as Jelly. It would do sweet FA for panel protection in the event of impact. Just hit a piece with a hammer and see what happens. Your thinking type 3s too much. I know this is a type3 section but if you get in a bug and pull out the back door panels youll see the cavity behind there goes straight through to the engine bay. Fastys are probably the same A hell of a lot of noise and fumes comes in through there if the door panels are old and warped. the early beetles before they started using the foam had stuffing in pillows sewn up with headliner scraps to fill the gap and stop the noise and fumes coming in.

It wasn't seen in anything before 71.

Volkswagens 1971 employee of the year for coming up with the foam idea needs their balls put in a vice.

I can assure you it makes a huge difference to noise and fumes in a bug, as I said the rear quarter cavity connects the interior straight through to the engine bay as you can see here and the foam that was used to keep it out.

Whether they just thought hey it works well it bugs, lets pump it into type 3s for shits and giggles as well is probably a likely scenario.

As L469 said, VW probably just wanted to cash in on saying look what we've done for sound proofing.
It doesn't have to work but it sounds good in commercials.

How about this. It is part of flow through ventilation.

Air comes in through air vents including demister.

Then though all the little holes in the headlining into the roof area.

Then makes its way to the back and there is the vent to the outside, being pushed by the fresh air coming in, and sucked out by the negative air pressure on the side of the vehicle.

The foam stops the air from going anywhere else but out the low pressure vent, not into a lower inner cavity, not behind the rear side trims, not under the back seat, not into the engine bay if it goes through there.

Do a search for 'flow through ventilation' Things were changing on motor cars in the 70's, and one of the things was more efficient demisting of front windscreen as a safety item.

HQ's were the first holden to get flow through ventilation in 1971. done through a vent in the rear quarter panel, using the back door gap as the low air pressure outlet.

In a VW bay bus, it was done through the vents on the inside of the front part of the front door, using the front door gap as the low pressure outlet.