Factory AC pressure switch details

[wwest]

My first purchase was in ~84, a used '78 Targa with 37,000 miles, rubber clutch failed shortly thereafter. Then the chain tensioners. Maintenance by Squire and myself. Wife and I put another 60,000 miles on the Targa with never a thought that A/C would be nice to have. Drove to Memphis and back, HOT mid-west, Kansas, Nebraska, etc. Got up at 0-dark-thirty, drove with the top off until the sun and heat became unbearable. Breakfast, top on, drive to late evening. Mostly 90 MPH+.

~1995, Purchased a '79 Targa, 80k miles, SLC, gift to a friend, A/C with aftermarket belly condensor. Wife and I drive it from SLC to Nyssa, NE oregon with satisfactory A/C. He seems to be happy with it.

~ 1997, Purshased another 78 Targa, virtual duplicate of our own 78, gift to our son. Ripped out and tossed afternarket, dealer installed, A/C.

~ 1998, Purschased an (the) 88 Carrera for our company's lead software engineer. He went on to greater things, challenges, we kept the car.

2000, purschased a used 1999 C2....tinited the windows. Drove cross country to Daytona (24 hours race)and back. Mightily impressed with interior comfort, climate control, vs the Carrera.

Later trip to/from Memphis (Blues Ball Auction)the front radiator fan failed in long construction zone across AR, HOT, August. Figured out how to keep the engine cooled and have functional A/C, comfortable all the way home where Squire repaired the fan controller.

That all got me to thinking about the shortcoming of the A/C in our 88 Carrera...so I started experimenting and shortly discovered the major problem. Not enough condensor cooling airflow in certain situations.

Added the initial set of rear engine lid cooling fans...BIG improvement.

Installed a factory A/C system ("pull-a-part") in our 78 Targa and did the same thing to it, except the additional cooling fans had to be mounted under the rear lid spoiler. Also a BIG, improvement.

[wwest]

Originally Posted by SilberUrS6

This may be true, but the design of any particular condenser does not cause this, it's the location of the condenser on the car.

Oh, but it most certainly does. Look at the relative ease of north/south, front to back, cooling airflow through the fins/vanes of the factory front condensor vs either of the aftermarket one's.

The aftermarket condensors might very well outperform the factory one when the blower/ fan is the primary source of cooling airflow, but not, NEVER, underway.

[wwest]

Originally Posted by JAR0023

Are you out of your mind? Do you really think all that air passing under the car, under the valance and chin spoiler is magically making two 90* turns and is flowing front to back through the front condenser?

Ever heard of a man named Bernoulli?

-J

That's actually MY argument.....the aftermarket front condensors are designed such that they mostly BLOCK front to back roadway airflow.

[quattrorunner]

Originally Posted by wwest

My first purchase was in ~84, a used '78 Targa with 37,000 miles, rubber clutch failed shortly thereafter. Then the chain tensioners. Maintenance by Squire and myself. Wife and I put another 60,000 miles on the Targa with never a thought that A/C would be nice to have. Drove to Memphis and back, HOT mid-west, Kansas, Nebraska, etc. Got up at 0-dark-thirty, drove with the top off until the sun and heat became unbearable. Breakfast, top on, drive to late evening. Mostly 90 MPH+.
.

wwest, don't misunderstand me please, I'm not trying to start something, but it just seems like, in all the threads about ac, you have got to have a dog in this ac fight. I'd ask others but why not ask you? What is your motivation? I have looked at your logic subjectively, and there is some merit to some of it, but at some point there is a limit that fans can do. At some point, there is some problem with the original design of the 911's ac system that a fan can not cure, so what is it that you have to offer other than confusing and upsetting a good thread? Do you sell fans? Do you own stock in all the fan factories? Why do you dislike Kuels stuff? It's obviously good. Are you trying to keep people from buying from him or just help them save money? Where do you stand in the ac world really? I have actually looked forward to you providing some data about your system, if you offer one, and just don't ever see it. I too want good ac, which I'm in the middle of acquiring parts for, and I just want to know. I even googled the satellite thingy you refereed too, just to understand what the hell your up too. Why do you keep coming back to these threads?
What is your motivation is what I'm asking sincerely. Thanks.

[brads911sc]

he is a socialist liberal democrat trying to save all of us stupid fools from ourselves and spending our hard earned money on snake oil. LOL.

Originally Posted by quattrorunner

wwest, don't misunderstand me please, I'm not trying to start something, but it just seems like, in all the threads about ac, you have got to have a dog in this ac fight. I'd ask others but why not ask you? What is your motivation? I have looked at your logic subjectively, and there is some merit to some of it, but at some point there is a limit that fans can do. At some point, there is some problem with the original design of the 911's ac system that a fan can not cure, so what is it that you have to offer other than confusing and upsetting a good thread? Do you sell fans? Do you own stock in all the fan factories? Why do you dislike Kuels stuff? It's obviously good. Are you trying to keep people from buying from him or just help them save money? Where do you stand in the ac world really? I have actually looked forward to you providing some data about your system, if you offer one, and just don't ever see it. I too want good ac, which I'm in the middle of acquiring parts for, and I just want to know. I even googled the satellite thingy you refereed too, just to understand what the hell your up too. Why do you keep coming back to these threads?
What is your motivation is what I'm asking sincerely. Thanks.

[SilberUrS6]

Originally Posted by quattrorunner

wwest, don't misunderstand me please, I'm not trying to start something, but it just seems like, in all the threads about ac, you have got to have a dog in this ac fight. I'd ask others but why not ask you? What is your motivation? I have looked at your logic subjectively, and there is some merit to some of it, but at some point there is a limit that fans can do. At some point, there is some problem with the original design of the 911's ac system that a fan can not cure, so what is it that you have to offer other than confusing and upsetting a good thread? Do you sell fans? Do you own stock in all the fan factories? Why do you dislike Kuels stuff? It's obviously good. Are you trying to keep people from buying from him or just help them save money? Where do you stand in the ac world really? I have actually looked forward to you providing some data about your system, if you offer one, and just don't ever see it. I too want good ac, which I'm in the middle of acquiring parts for, and I just want to know. I even googled the satellite thingy you refereed too, just to understand what the hell your up too. Why do you keep coming back to these threads?
What is your motivation is what I'm asking sincerely. Thanks.

LOL, we have been asking him a couple of simple questions now in every single thread he craps in.

He won't answer those, so it seems unlikely he won't give you any SUBSTANTIAL answers to your technical questions. He obviously thinks that GTI stuff is very overpriced. Considering the rest of the market, GTI seems to have a reasonable price going for the stuff. He also seems to think that somehow, if you could only move air over the condensers more, the system would be adequate - then uses his own experience as "proof". Well, my experience happens to be this:

When I got the car, it had a stock system. It blew cool air, but in the summer, the temp. delta was only about 15 degrees from OAT. And that was cruising along at 65 MPH. I was not impressed. Giving it a full R12 charge only helped marginally when the OAT was 100+ degrees. Not only that, but after one year, I had to add five additional ounces of R12, and the subsequent dye leak check saw zero leaks at any of the fittings. So, search Pelican. Swap front condenser, evaporator evap fan, temp control and fan switches, go to barrier hose, switch to R134a, courtesy of GTI.

Well, now I can get the cabin very cold, and it will stay cool even when the car sits at a light. It doesn't take that long to fully cool down the black interior, and on the highway, the car stays as cold as I want it to be only if the car sits at idle in the full sun does the air output warm noticably - but the air output is still cool enough to keep up with the heat input.

The curious thing about wwest's posts is that he holds up his personal experience as definitive, but everyone else's experiences don't matter in the least. Never mind being terrible science, his position is not even remotely logical. Where did my R12 go? If it had leaked at a fitting or a hole or even some relief valve, the dye would show up under UV. There is only ONE correct answer for where the R12 went, because logic dictates only one potential place, when you've eliminated the metal parts and the fittings. Yet I am to believe that system overpressure is the cause of my R12 leak, and that somehow, only the gas leaked, and none of the oil with dye in it. That's tough to explain away. In fact, wwest doesn't even bother - he'll just change the subject.

He makes claims about condenser flow, without ever having tested the flows. Without even having the things in his hands. He just looks at a picture and *knows*. Yes, his intellectual forebearers *knew* that the world was flat, too. Then, after that, they *knew* that the Earth was the center of the universe.

It's not a matter of what wwest knows. It's that so much of what he knows is obviously, demonstrably untrue.

[wwest]

Originally Posted by quattrorunner

wwest, don't misunderstand me please, I'm not trying to start something, but it just seems like, in all the threads about ac, you have got to have a dog in this ac fight.

First, and I guess foremost, I'm a commited DIYer, shade tree mechanic, whatever, clearly NOT a professional.

I'd ask others but why not ask you?

What is your motivation?

Exploring new worlds..??

I have looked at your logic subjectively, and there is some merit to some of it, but at some point there is a limit that fans can do.

Yes, but look athe number of posters that have added TWO fender mounted condensor/fan combinations and seem, state, that they are extremely pleased with the result? Three fans for cooling condensors plus one of the oil cooler...

Could the rear lid and front lip condensor be removed from those systems and still remain satisfactory...?

At some point, there is some problem with the original design of the 911's ac system that a fan can not cure, so what is it that you have to offer other than confusing and upsetting a good thread?

What, which, well known A/C problem will fans NOT cure. We have aftermarket condensor/fan assemblies, evaporator fan upgrades....

And now I suggest that those aftermarket fans could possibly be used to alleviate the refrigerant leakage problem...

Any thoughts, theories as to why that might not work?

Do you sell fans? Do you own stock in all the fan factories?

No..

Why do you dislike Kuels stuff?

It didn't start out that way, it was only after Kuehl began attacking my rear lid fan solution in one manner after another that I began to realize why. If the fans work, they do, some of Kuehl's inordinately and high profit margin products are OBSOLETE.

It's obviously good.

Yes, but quite possibly now worthless if, AS, more and more of his customer base begin to recognize that in the majority of cases there is a much more cost effective solution.

Are you trying to keep people from buying from him or just help them save money?

I think those may be mutually inclusive...

Where do you stand in the ac world really?

Wasn't a'tall interested in A/C until I purchased a new 1992 Lexus LS400 and almost immediately discovered its propensity for spontaneously and almost instantly fogging over the interior windshield surface in certain specific circumstances.

Filled for Lemon law repurchase (lost) and inadevertently become my own expert witness.

Then later got interested in the "whys" of refrigerant loss in my '88 Carrera. That lead me here.


I have actually looked forward to you providing some data about your system,

Putting on my own "black hat", I don't see that these is really any data that I could supply that would be convincing other than what I have already put forth. That being my own expereince with the '78 Targa and 88 Carrera. For instance folks put up pictures of vent temperatures but IMO that proves NOTHING.

if you offer one, and just don't ever see it. I too want good ac, which I'm in the middle of acquiring parts for, and I just want to know. I even googled the satellite thingy you refereed too, just to understand what the hell your up too.

Why do you keep coming back to these threads?

Why did I contribute, freely, the travel expenses, man hours, and equipment needed for NASA to make one last contact with Pioneer 10 as it departed our solar system thirty years after launch....

I like being of help, contribute to the PP knowledge base, when and if I can.

What is your motivation is what I'm asking sincerely. Thanks.

40 some odd years being a "fixer", mostly computers, and then wandered into computer design.

If it helps "data wise" both my wife and I consider the A/C system in the 88 Carrera very compariable to the system in our 01 C4.

[quattrorunner]

Originally Posted by wwest

40 some odd years being a "fixer", mostly computers, and then wandered into computer design.

If it helps "data wise" both my wife and I consider the A/C system in the 88 Carrera very compariable to the system in our 01 C4.

Thats pretty much exactly what I thought.....
I was hoping for more though.
I think you'r bored and just want to upset the applecart.
Listen to me for a second. I'm not stupid, and I'll stretch and say that most the guys here are not stupid. Some have more real world experience than others sure, but you need to step back and let us be. We don't need you. Your "experience" is fine. I'll file it away and keep it for future refrence. And it's there for everyone to search the archives. Just let them be searched.
You need to trust me on this, we will get along in the ac world without you. Nothing will happen to us that you need to worry about. Everyone of us make our decisions on our own. Sometimes we make mistakes, but isn't that what life is all about? Leave us alone, we will survive without your invaluable knoweladge on the workings of the ac system and dynamics of heat transfer.
I'm intrested to read about ac improvements. I've learned about your all I can stand from you.
OK, I'll get a fan. GO AWAY.

[brads911sc]

Lol

[SilberUrS6]

Originally Posted by brads911sc

Lol

^^^this

[wwest]

Originally Posted by SilberUrS6

LOL, we have been asking him a couple of simple questions now in every single thread he craps in.

He won't answer those, so it seems unlikely he won't give you any SUBSTANTIAL answers to your technical questions. He obviously thinks that GTI stuff is very overpriced. Considering the rest of the market, GTI seems to have a reasonable price going for the stuff.

He also seems to think that somehow, if you could only move air over the condensers more, the system would be adequate -

The condensor is simply a heat exchanger, HOT refrigerant GAS to air, EXACTLY as is our evaporator, except HOT air to refrigerant GAS. Our evaporator..you know, the one that can be made more effective via buying Kuehl's "hurricane blower" upgrade. Move MORE air, EXCHANGE more heat.

Or, in your mind, is that hurricane blower you seemingly purchased just another bit of SNAKE OIL...? Seemingly so.

then uses his own experience as "proof". Well, my experience happens to be this:

When I got the car, it had a stock system. It blew cool air, but in the summer, the temp. delta was only about 15 degrees from OAT. And that was cruising along at 65 MPH. I was not impressed. Giving it a full R12 charge only helped marginally when the OAT was 100+ degrees. Not only that, but after one year, I had to add five additional ounces of R12, and the subsequent dye leak check saw zero leaks at any of the fittings. So, search Pelican.

Swap front condenser(Obvious NEGATIVE effect), evaporator(well done except for $$$ vs value) evap fan(Wait, weren't we just told that more airflow doesn't help??), temp control(Replace a working, functional control with a new one??) and fan switches (Switches, plural? What, no PWM fan control?), go to barrier hose, switch to R134a, courtesy of GTI.

"..switch to R-134a, courtesy of GTI.." GTI and yet no pressure switch, not even a binary pressure switch...?? Must have been before GTI learned...that the world was not flat.

Well, now I can get the cabin very cold, and it will stay cool even when the car sits at a light. It doesn't take that long to fully cool down the black interior, and on the highway, the car stays as cold as I want it to be

only if the car sits at idle in the full sun does the air output warm noticably

Yes, and obviously that would be a lot less likely to happen if the condensor cooling effectiveness could be improved in that circumstance, situation....say with GTI's fender mounted condensor/fan assembly.

- but the air output is still cool enough to keep up with the heat input.

For how long....

The curious thing about wwest's posts is that he holds up his personal experience as definitive,

but everyone else's experiences don't matter in the least.

There seems to be two groups of "everyone else's experience" in this regard.

1.)"Everyone else" that adopted some form of GTI's or other aftermarket solution, for which to my knowledge no one, including me has disparaged functionally, only $$$ and obsolescence.

2.) Those few, definite minority, that have used a DIY technique to add some form of additional cooling capability to the front or rear condensor, mostly rear.

Both experience's MATTER.

Never mind being terrible science

Strange...it's the EXACT same SCIENCE GTI uses.

his position is not even remotely logical.

Obviously so for those that can't, will not, think things through logically due to their need to defend a decision made, and $$$$$ spent, years ago.

Where did my R12 go?

Obviously..? No where, provided the refrigerant pressure never rises to high.

If it had leaked at a fitting or a hole or even some relief valve, the dye would show up under UV.

But maybe only with the system under extreme pressure...Like what might happen with a malajusted or failing thermostatic switch, a rather common failure according to Kuehl. Kuehl's recommended preventative measure, use a binary pressure switch...

There is only ONE correct answer for where the R12 went, because logic dictates only one potential place, when you've eliminated the metal parts and the fittings.

And just how, what procedure was, is used, to eliminate the metal parts and fittings (O-rings??). Replace the hose AND fittings...here comes the chicken or egg question...

Yet I am to believe that system overpressure is the cause of my R12 leak, and that somehow, only the gas leaked, and none of the oil with dye in it.

The early belief, descerned and verified via scientific laboratory studies, was that non-barrier hoses would leak R134a due to the smaller molecular structure vs R-12. I would imagine the same argument could be made for the oil, even larger molecular structure than R-12. Plus there is the issue, FACT, of the oil having a dramatically higher viscosity vs either refrigerant.

That's tough to explain away.

Not at all, see above. In point of fact later scientific laboratory studies with a "real world" hose environment indicated that "legacy" non-barrier hoses, those that had been previously permeated with R-12 lubricating oil, did not leak refrigerant, R-12 and R-134a, even with refrigerant pressures elevated to operational levels.

So, if you wish to dispute the findings by DuPont, the SAE and the EPA, be my guest.

In fact, wwest doesn't even bother - he'll just change the subject.

Sure did...

He makes claims about condenser flow, without ever having tested the flows. Without even having the things in his hands. He just looks at a picture and *knows*.

There are times that one can come to a quite valid conclusion that way, but not this one.

Yes, his intellectual forebearers *knew* that the world was flat, too. Then, after that, they *knew* that the Earth was the center of the universe.

All very true, yours, mine, and..Kuehl's

It's not a matter of what wwest knows.

It's that so much of what he knows is obviously, demonstrably untrue.

Not yet, and more certainly, obviously, not by you.

Since you do not have the fender mounted condensor/fan, nor the binary pressure switch, AND live in a high desert area climate, you seem to be a good candidate for testing my theory more completely. Find a time to pop over for a day or two, let me know when, and I'll be at the ready. August is just around the corner

nnnn

[brads911sc]

So you want to use someone elses car to test your theory? LOL

Originally Posted by wwest

Since you do not have the fender mounted condensor/fan, nor the binary pressure switch, AND live in a high desert area climate, you seem to be a good candidate for testing my theory more completely. Find a time to pop over for a day or two, let me know when, and I'll be at the ready. August is just around the corner

nnnn

[wwest]

Originally Posted by brads911sc

So you want to use someone elses car to test your theory? LOL

Want, NO!

Volunteer my services to fix a "broken" GTI A/C system, yes, and with great pleasure and satisfaction.

If he wished to keep the results totally secret that would be fine by me.

For myself the theory is so well founded and the trials so satisfactory that no testing is required.

[quattrorunner]

Originally Posted by wwest

For myself the theory is so well founded and the trials so satisfactory that no testing is required.

What?
So well founded. That means there IS data?

[SilberUrS6]

Originally Posted by brads911sc

So you want to use someone elses car to test your theory? LOL

Holy crap.

What a tool. But this proves my point - he is perfectly willing to test his hypotheses on other folks' cars, on their dime. After railing over Griff's costs.

What a narcissist.

[SilberUrS6]

Originally Posted by quattrorunner

What?
So well founded. That means there IS data?

LOL. Yes, he presents it every thread. "I like how my stuff turned out, and anyone who disagrees is a fool."

Circular reasoning is circular.

[tirwin]

For myself the theory is so well founded and the trials so satisfactory that no testing is required.

I developed a theory that unifies special relativity and quantum mechanics today. It is so well-founded that I'm not bothering to publish the details in any peer-reviewed journals nor subjecting it to testing.

[SilberUrS6]

Originally Posted by tirwin

I developed a theory that unifies special relativity and quantum mechanics today. It is so well-founded that I'm not bothering to publish the details in any peer-reviewed journals nor subjecting it to testing.

I have some Monty Python "Holy Grail" quotes all lined up on this one, LOL.

[tirwin]

Quote de tirwin

I developed a theory that unifies special relativity and quantum mechanics today. It is so well-founded that I'm not bothering to publish the details in any peer-reviewed journals nor subjecting it to testing.

I have some Monty Python "Holy Grail" quotes all lined up on this one, LOL.

Why do witches burn?

[quattrorunner]

Hey, this is kinda fun....
I got me some well founded and supremely "founded" scientific theories too.
It is scientific if I tested it in my dreams right?