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rear pillar vents needed?

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torana Slammed & Awesome Dubber

85 posts · joined Jan 2009 ·

#894196
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

Joel Now containing 100\% E-Wang

9,368 posts · joined Feb 2006 ·

#894205
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.

torana Slammed & Awesome Dubber

85 posts · joined Jan 2009 ·

#894215
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 👍

vlad01 Compulsive Aussie Vee Dubber

4,270 posts · joined Jun 2010 ·

#894229
foam was for structural reinforcement i believe.

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

71 notchback,
Past owner of, 70 NB, 73 SB and 72 FB TLE

Joel Now containing 100\% E-Wang

9,368 posts · joined Feb 2006 ·

#894234
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

68AutoBug Beetle Restorer - Experience over 138\% - YIKES --

11,654 posts · joined Aug 2002 ·

#894320
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
- Helping keep Air Cooled VWs on the road - location: SCONE in the Upper Hunter Valley - Northern NSW 320 kms NNW of SYDNEY---

L469 Officially Full-On Dubber

288 posts · joined Mar 2010 ·

#894324
68AutoBug wrote: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
the foam you get now is not water proof it is water resistant
to prevent mould it still holds water when wet so foam is still a no!!
no!!

how can something that is open cell be water proof ?

L469 Officially Full-On Dubber

288 posts · joined Mar 2010 ·

#894327
vlad01 wrote: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!

L469 Officially Full-On Dubber

288 posts · joined Mar 2010 ·

#894328
torana wrote: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
if you are keeping the car original keep them if not fill them in but dont use foam of any kind .




vw cut some costs with ths one stamping the vents into the shell as an alternative too pop out rear qtr vent windows in the rear which were an extra cost option . vents were standard on all the beetles and type 3 and 4 from 1971 0nward

vlad01 Compulsive Aussie Vee Dubber

4,270 posts · joined Jun 2010 ·

#894333
Joel wrote: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.

71 notchback,
Past owner of, 70 NB, 73 SB and 72 FB TLE

vlad01 Compulsive Aussie Vee Dubber

4,270 posts · joined Jun 2010 ·

#894335
L469 wrote:
vlad01 wrote: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.

71 notchback,
Past owner of, 70 NB, 73 SB and 72 FB TLE

L469 Officially Full-On Dubber

288 posts · joined Mar 2010 ·

#894343
vlad01 wrote:
L469 wrote:
vlad01 wrote: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.

i am in the motor trade i see cars all brands pulled apart
it is not for structure . a crumple zone is designed to deform before a safety cell putting a solid block of foam in the crumple zone transfers the force of impact directly on the safety cell .not what it is designed too do. it was intended by manufacturers
to combat drumming,wind noise and again in the case of the engine exhaust fumes etc entering the cabin of the car

L469 Officially Full-On Dubber

288 posts · joined Mar 2010 ·

#894345
vlad01 wrote:
L469 wrote:
vlad01 wrote: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.
the rear structure of the car. rear pillars included are the crumple zone designed too absorb impact in a rear end collision

glass the bonded kind in new cars is the main strength in the roof area.

Joel Now containing 100\% E-Wang

9,368 posts · joined Feb 2006 ·

#894369
vlad01 wrote:
Joel wrote: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.

L469 Officially Full-On Dubber

288 posts · joined Mar 2010 ·

#894374
yes joel thanks for the common sense input.

vlad01 Compulsive Aussie Vee Dubber

4,270 posts · joined Jun 2010 ·

#894499
Joel wrote:
vlad01 wrote:
Joel wrote: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.

Have you tried caving in steel cavities willed with foam with a sledge hammer?

I have and it only dents but doesn't allow you to crush it in. Foam inside a sealed compartment is remarkably strong.

Yes you are right about this being a type 3 section, type 3 is different to the bug, so different purposes may well been at hand.

Actually now that I think about it, foam wasn't seen in the type 3 till 71 or 72 I think?

I cut up a 70 fasty last year, completely down even the rear pillars, no foam and Like I said before the cavities in there are completely separated and sealed off from the cabin and engine bay, so no air can even pass from the engine bay, its ridiculous to even think that coz the type 3 structural design can not even allow for this. Not even close to the engine bay!

So the theory of stopping fumes and noise is thrown out the window.


I'm sorry but I don't believe its for sound and fumes, bug maybe, but type 3? does not make logical sense since the inherit design doesn't cause issues, So structural is the only thing that come to mind as for a reason.

71 notchback,
Past owner of, 70 NB, 73 SB and 72 FB TLE

Joel Now containing 100\% E-Wang

9,368 posts · joined Feb 2006 ·

#894517
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.

helbus Administrator Mad fabricator, paint and body

7,386 posts · joined Sep 2002 ·

#894536
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.
EJ22 into Bay Microbus - Finished project build thread- click on this spot here for info

L469 Officially Full-On Dubber

288 posts · joined Mar 2010 ·

#894553
helbus wrote: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.
well put i agree 100%