First, your A/C system has no "fresh" air inlet mode, that means that in order to most QUICKLY flush the interior of the HOT atmosphere you must lower the windows slightly during the initial few driving miles and maybe even use the fresh air intake fan as an assist.

The fact that the interior surfaces are heat soaked means using the above method for a somewhat extended period, mostly as long as the temperature of the outside incoming airflow is low enough compared to the A/C "supply".

It might be of help for you to know even my '95 LS400 requires the use of the above method on occasion.

Why do you ignore me every.single.time I ask for you to test your kit. It's amazing, and honestly a bit sad, how fervently you post on AC threads RIGHT up until someone asks for data. POOF. You're gone.

I have offered to send you the materials to test it, to find someone in your area to test it against, and yet you just stop responding to me.

You are really something, sir.

Both cars that have my "kit" work perfectly fine in my environment, plus trips t/from central MT, at least one of those in 90F climate conditions.

But the Naysayers insist that the "kit" is too simple a solution, too inexpensive, to work in the HOT southern states.

Not to ignore, just cannot easily replicate the test enviroment to the level required to convince the naysayers.

Both cars? Who has your same setup and why aren't they posting defending this setup?

What - you can't take vent temps when it's hot out? Nobody here is doing these tests in a NASA lab. Sounds to me like you know what the vent temps are going to show and you're embarrassed that they temps won't match the raging kuehl-boner that you have.

Howdy WYDBODY1986,

I respectfully disagree a bit (smile) YOU WOULD RATHER HAVE A COLDER A/C SYSTEM WITH VENT TEMPS BELOW 40F

I think you have gotten some poor recommendations= “pretty much all of the recommended mods to my AC”


Wellpers I live in sunny and extremely muggy South Florida too, in Ft. Lauderdale (smile).

I know a bit about what the sun does in south FL to 911’s interiors and body, and when you first open the door with the windows closed before you even sit in the driver’s seat and the parked 911 sitting in the sun sometimes even before noon and the inside air temp is an honest 180 F in low humidity days before you start the engine and turn on the a/c (smile) and this is before August and September ouch.

I am an engineer and custom design and manufacture early model 911 A/C extremely cold state of the art new technology solutions
I have several new A/C inventions

i.e. this one available only for south FL 911 owners http://forums.pelicanparts.com/porsche-911-technical-forum/744551-seeking-south-florida-911-930-owners-interested-revolutionary-c-system-invention.html

But that particular invention might not be within your budget, however I have others that have lower costs related to my PFC 911 custom made heat exchangers.

Regardless you do not specifically say what you did and included in your $2000.00 expenditure a/c improvements over the past few years expenditure, and a/c technology has greatly changed in the past few years; for all I know you are still running your stock oem front and rear tube and fin condensers ?

No offense but I have a feeling from the vent and ambient temps you posted you need better/newer technology condensers than you have so you had lower vent temps then you posted

FYI your condensers are the real key over evaporators for colder vent temps and comfort on early 911s

BTW Once your a/c vent temps can go/drop BELOW 45 F regardless of humidity @ 95 plus ambient, it’s a game changer EVEN using the OEM original a/c blower

I see this all the time, people mindset thinking blowers and fans is the answer when the real answer was their a/c system needed to get colder then it is;; then after they chase this fan/blower mindset route they may think they notice a degree or two improvement, BUT if they would have had a few degrees colder a/c system they would have been very cold with their original blower fan set on its lowest speed.

Now for those reading this and possibly doubting or want to dispute what I just typed, my old 1992 Geo Storm that is a wagon back (station wagon) body style has far more window area and includes a rear opening hatch than a 911 has and excellent a/c blowers with its oem stock a/c system running R-12 and always gets vent temps of 45F even @ 95 F ambient.

Know the truth about wwest
 

What a CROCK of clueless BS and STUPID!

ROFL ROFL ROFL at this absolute pure ignorance and stupidity from this A/C thread troll

Wwest, wrinklepants apparently offered to provide you with equipment
and you recall the several posts you made about your theory of engine heat causing the ac system to "over pressurize", and how to do the simple test to see if the engine heat raises the system pressure when the car is off:

1) Drive the car hard for a period of time (lets say until the oil temp is mid way) with the ac on, lets say in any ambient temp above 70F.
2) Stop the car, turn off engine.
3) Connect your AC gauges, put deck lid down,
if you wish to cover the openings around the lid (to insure that heat rising
from the engine is absorbed by the condenser and the refrigerant gas expansion
over pressurizes the system beyond is normal operating pressures),
4) Watch the gauges. Document your observations, and report back to the forum:
a) the high side pressure when you connected your gauges,
b) how high the pressure rose on the high side if any,
c) how long it took for the high side and low side to equalize.

Connecting a set of gauges seems to be a rather simple task according to many of your peers on the board, DIY's included.

Frankly its not a matter of replicating anything, nor is it a matter of having a unique
or controlled test. Rather it is a simple observation.

You have noted in past posts that you never connected a set of gauges to your 911.
Maybe this would be a good time, before the AC season heats up. An opportunity for you to check your system to insure everything is operating correctly. Just like checking your tire pressures, oil level, air cleaner, etc.

I would imagine that since you have been posting your theory for some time now that many forum members here are curious as well. I guess we could start (author) a new thread, say something like "Test Your AC System Before the Season", and provide the steps. Maybe you'd like to take on that task? Naturally I'm curious as well, never mind that I have yet to observe your theory, but just curious.

I'll give you some time to think about it. I guess we can assume that if you don't take on the challenge shortly you would not feel offended if the "Pre-Season AC Checkup" was posted.

WWEST theories...Chronologically...

1.) The factory system requires additional refrigerant cooling capacity, or improved efficiency of existing capacity, in order to provide "reasonably" adequate cabin A/C cooling on a hot August day in Houston Texas. Engine lid fans or fender mounted condensor/fan put forth as a suggested solution.

2.) Adding a hi/lo pressure switch would prevent system over-pressures that might be the cause of non-barrier hose leakage.

3.) Adding a trinary pressure sensor with the extra element controllling the additional refrigerant cooling capability might abate the non-barrier hose leakage problem.

4.) Having an "after-run" capability to enable any condensor cooling capacity (front lip blower?) might absolve the leakage problem.

"1" Accepted, seemingly, by the community at large for non-Texas-like August climates.

"2" Hi/lo pressure sensor PREVENTS system over-pressures resulting from compressor cycling. Verified by Kuehl.

"3" "Might.." No dispute within the community at large.

"4" "Might.." No dispute within the community at large.

Kuehl: Would it suffice, really, to insert a probe thermometer into the engine lid condensor fins and watch the result post engine shutdown in the proscribed conditions.

I purchased a guage set by haven't had the need to use them yet...

NOPE!
We all know the engine is hotter than "OAT" (outside air temps).
Your question is the heat from the motor turned off great enough to cause your theories:

"Theory1 " - the radiant and convention heat from the motor
could cause the refrigerant psi to rise above the operating pressures
the system has when it is operational; excessive refrigerant pressures
above normal cause "something" to leak when the system is turned off.

"Theory2 " - the low side and high side pressures takes a very long
time to equalize with a frozen evaporator or an evaporator with a core
temp below 32F. For this you could simply unplug the compressor
clutch from its power wire by the oil filter and run a hot wire from
the fuse post on the LH side engine's power panel and just let the compressor
operate until the evap is below 32F and then turn off the motor. Have
your thermometer inserted in the evap core; you can either remove your
thermostat's sensor tube or drill a hole in the top of the box adjacent to it
you have to get your thermometer's sensitive point at least 2 inches into
the evap core, so figure distance between the top of the evap box and
the top of stock evap core is about 1" min.



At this juncture you don't need a electronic refrigerant sniffer, you just
need to observe pressures after the engine turns off

Gosh guys.

Lets stop the pissing contest.

I think everyone following these AC threads has judged the value of your opinions.

Please stop.

I think we all have respect for your knowledge and opinions, suggest you both show a little respect for each other, and the readers of this forum.

I would jump in and offer my opinion on the posters question, but no one would read it because of all the bickering going on.

1. Wwest is actually a female

2. The blue sky isn't actually blue.

3. My feet currently stink

4. Kuehl is cool. Can't think of a double entendre for Wwest.

So - since I don't see anyone taking the time out of their day to respond to my idiotic and incessant posting about all this - I can only assume this stuff is true. I mean, people give such large fvks about what I do that, clearly, people would be taking the time out of their day to prove me wrong - if I was indeed wrong.

This is one of the basic tenants of science, people! You know all that **** about having a theory, testing, and validating that theory so it becomes fact? Yeah - total BS. The right way to do it is propose ideas, wait for people to do the work proving you wrong, deflecting on proof points to make it seem like you know stuff, and if they don't prove you wrong in a way that makes you happy, then by default, you must be right.

Wwest has theories that are not rooted in engineering practices. He doesn't test, validate, or share any of his data. I have yet to hear of anyone that lives in a remotely hot climate that runs his same setup. Wwest does not live in a notoriously hot climate. These are all facts and any rational person that puts this info together would come to the conclusion that you either don't have any idea what you're talking about, you're not intelligent enough to understand test results, or you lack some type of validation in your personal life, and you get something out of all these posts that you're not getting elsewhere.

As a man - I feel embarrassed for you. You remind me of this guy I work with in the military that never went to college (maybe you did), but gets a lot of info from books. He's really into his faith (nothing wrong with that), and loves having discussions with my about evolution vs creationism. *Every one* of these conversations is him throwing out unrelated ideas that prove evolution doesn't exist and every time I counter with knowledge you'd learn in HS science class, he deflects to something else. His argument about radioactive decay is "were you around to see it go through the whole decay process?" No. "Then how do you know that's how it decays?" I mean - for someone that barely graduated HS, never went to college, doesn't put much faith in science, and has an agenda that he's trying to validate - how in the world do you rationalize radioactive decay to this person? When I see you debate with Kuehl - this is the frustration I feel because you always deflect, ignore, change the subject, or just stop posting when things go over your head or you realize you're wrong.

Prove your point with data - or Shut.the.****.up. If you haven't figured it out from reading all these AC threads, nobody cares about what you're saying, and in truth, it looks a bit sad because it seems you enjoy the negative attention. Nobody respects you for what you're doing. Nobody is doing any of your suggestions. Kuehl runs an actual business, contributes here, and throws down a lot of knowledge that he doesn't need to. You're time spent here has benefited NOBODY. Is that the kind of contribution you're trying to make to this community?

Gee, last Summer I drove my 85 Carrera to Salt Lake City in 105 degree temps. We took long drives, stopped and shut off the engine. Take a 15 to 20 minute break to gas up and relieve the bladder. Fire up the car and drive off and have cold air in short order. I did the same thing the year before in Savannah GA, I did the same thing the year before that and the year before that. I will do it again this year.

I have not had to add one ounce of refrigerant in many years.

I have Griffith's system, barrier hoses, two fender condensers and the stock front and rear condensers. I have the Griffith's evaporator. I will upgrade to the bigger blower eventually, but the stock blower with cold air is enough for now.

With no doubt the AC upgrade is the best upgrade I have done to my 911. Before the AC upgrade I was reluctant to drive my 911 in the HOT summer months. Last year Oklahoma had the temps that made Texas look cool.

I like proven simple solutions. No smoke and mirrors. I have no desire to modify the front bumper to fit a huge condenser or radiatior in there.

I think I have long since verified, posted, that the low side pressure remains stable, depressed, in the conditions put forth, for more time then I had patence waiting for. I waited, watched, the low side pressure guage long enough to be satisfied that my theory was well founded.

No one, insofar as I am aware, has taken a position indicating that the new barrier hoses do not prevent the leakage known to exist with non-barrier hoses but only in the Porsche air-cooled engine environment.

6 weeks into the tenth grade (Humes) I joined the USAF, never looked back.

http://seti.sentry.net/archive/bioastro/2003/Feb/0293.html

Worth reading:

http://forums.pelicanparts.com/porsche-911-technical-forum/472523-87-911-c-upgrade-progress-2.html#post4697549

Even better:

http://forums.pelicanparts.com/porsche-911-technical-forum/304231-let-ac-fun-begin-oh-blow-45-a.html

Is this the same setup you have? A modified tail to accept a giant condensor, Rennair procooler, barrier hoses, two huge fans, and a bunch of custom connections?

History....

Quote:

Originally Posted by Jim Sims (Post 2864975) "Only when needed. Like at idle, stop and go or rising pressure...." Then you likely want a trinary pressure switch. "At WOT, they and the compressor should cut out." You will want to do this with a separate WOT cutout switch. "Also maybe when on the brakes???? I have no decel valve anymore..." Don't follow your reasoning here - are you trying to prevent "clutch in/throttle at idle" engine stall when braking? "I like delaying the start of the fans when you turn on the A/C. There will be a delay (when using a trinary pressure switch); length of delay will depend upon system temperature, air temperature and air flow over the condenser from the engine fan and aerodynamic effects. "Is there any value to having afterrun. I.e., running them after clutch cutoff? Like an afterrun coolant pump?" Only if the clutch cutoff was due to excessive discharge pressure; the trinary switches have a dead-band on the intermediate pressure contact function. "How fast does high side pressure drop when the compressor stops? Seconds or minutes??" Never ever timed it (I recall it being more than a few seconds though). It will depend on what the expansion valve is doing (how cold is the evaporator and is air blowing through it) and the temperature of the high side refrigerant. "What about location? I may have room right off the -6 out of the condenser up in the tail." Somewhere before the first condenser inlet not at the outlet. "Stock driers have a cutoff at the drier???" Some do, but it is usually just a high/low pressure cutout.

More...

If you have new information to settle the squabbles, then please bring it. Otherwise, these threads will continue to go in this direction because one of the parties gets enjoyment from the presentation of false and misleading information. Each time the information is presented, it must be refuted, or else someone out there might actually believe the false info.

Wishing for peace is great. Working for it takes effort.

Because he enjoys busting Griff's b@lls. He enjoys the attention.

I have both an early car with dealer installed A/C front and rear condensers; and a 91 964.
The early car achieves much lower vent temps,( easily 10 degrees less) than the 964 yet the 964 has much better cooling. The biggest difference is the amount of air the 964 moves, more and bigger vents, a higher capacity twin fan evaporator is the ticket more than a single high speed fan blowing through smaller vents.
I'm pretty sure the Kuehl system with 4 condensors has way more square inches of condensing capacity than my 964. I think his systems work well but they would really benefit from more air volume, but for that all the ventilation plumbing would have to be upgraded.
The one question I have for Mr. Kuehl is why he does not offer a large underbody condensor as an alternative to his rear wheel kits. I have been in cars with the underbelly condensors and they work VERY well. There used to be a company in California who sold these kits, but no longer do so.
I initially thought they were more prone to damage but the ones I have seen seem to survive quite well.

Underbody, belly, condensors are almost totally non-functional except underway at a reasonably high roadspeed. Think of the front lip condensor, radiently heated from a HOT roadbed surface, and NO convection airflow path.

It is a given that the major shortcoming of our A/C system is the shortage of refrigerant cooling efficiency would not in motion, so simply adding the underbody conndensor is of no help.

That, and being subject to damage via roadway debris, is probably why they might no longer be available.

Theoretically that is what I thought, but their size makes up for the lack of airflow and they seem to survive as the examples I've seen have been on the road for years.

You never answered my question - that setup you linked is that the same you you have? He showed his data, and it seems to work. So, if that's what you have - I'll stop busting your balls. But, you can't really claim that it's just a few fans. He had is tail heavily modified, and that's usually beyond what some folks are willing to do. I've never heard you mention a giant condenser and modified tail, before.

200k on my car with track days - and it's the original condenser. My car is lower than euro, too.

I've read this thread with interest. I also have an 88 3.2 with stock A/C components (I think). I see that many of you did the whole thing all at once. My question is, is it possible to do this piecemeal? Like for example, drier replacement first. Or front and rear condenser replacement first. Then hoses and evaporator later...

I ask because I didn't want to spend for all of it at once, and those two items (driers and condensers) seem to be relatively easy drop-in replacement jobs. Thanks in advance!

OK, #1: Don't listen to anything wwest has to say. Just about EVERYTHING he says is contradictory to industry standard AND what automotive AC experts say.

From there: Generally, every time you open up your AC system, some atmospheric moisture will get in, depleting the desiccant in the drier. So, my suggestion to you is this: Open the thing up ONCE. But AFTER you've bought all the components. Buy the hoses, save up. Buy the evaporator, save up. Buy the evap fan upgrade, save up. Buy the front condenser, save up. Over the course of a couple of years, you will have assembled the whole kit, and be ready to install all in one go.

Wildthing,

As Eric pointed out its wiser to "do the job right, once".
If you try to piece meal a job you end up spending more time and money
on the objective.

Every time you need to replace an item that is in the refrigerant circuit,
such as driers, hoses, o-rings, evaporator, expansion valve, condensers
or compressor; you have to recover the refrigerant and the evacuate,
charge and test. That is costly and time consuming.

First you want to determine your 'needs' up front, rather than trial and test
what you think you need. Hence, evaluate you needs and what is needed
to achieve them. Needs are based on your driving climate, vehicle characteristics,
your personal needs and number of occupants.

Most of the better ac suppliers offer 'packages' which are typically
less expensive than buying each part piece meal. The key is what
do you need in your package. Alike planing for a family in the future,
do you need a 2 bedroom house with 1 bathroom or a 4 with 2.

First learn the short comings of the stock system, ways to improve upon
them and how the system works. They you can make an educated
decision; there are a few suppliers of systems and parts, whom you choose
will be your decision. Read the forums: Renn and PP here.

And,

Read The Mr. Ice Project . Its a great primer for the DIY and very informative.

Exactly. Living in FL or TX and wanting AC in stop and go traffic will be one thing. Living in Montana and wanting it for long drives is something totally different.

Post up where you're from what your driving habits are - and folks can recommend a setup that will be adequate for what you want to do without breaking the bank.

kuehl,
My situation is this: I live in LA - I take my 81 911SC out maybe 4-5 times during the summer, and where I live, the days are in the 90s. After a drive, my shirt is soaked. For the amount I drive, I am satisfied with the factory air (York compressor) when it worked. My problem is, although my system was checked for leaks and none was found, my system won't hold a charge for more than a month or so (maybe less). After charging with refrigerant several times, I stopped using my AC. This is probably 15 years ago. From all I read, I am assuming my hoses need replacement with barrier hoses. With the refrigerant change I need, I am guessing I also need a replacement drier. My question is, can I just replace barrier hoses and my drier and expect that by doing this, I will no longer have to recharge with refrigerant? Or at least recharge it every couple of years or so.

aoncurly,

I know you directed your question to kuel, but here's some food for thought. The A/C system in your car is 32 years old. It has 5 major components all linked by hoses. Anyone of these components or their connections can be a potential leak point. You could replace all your hoses to find that there is a cracked tube in the front condenser, for example. You can use die or a halogen leak detector to find your leak. I actually had a leak in the rear condenser where the ignition coil had been making contact and rubbed a hole through. I was planning on a full system replacement anyway, so that gave me the motivation to do it.

Spoken like the TRUE snake oil salesman he is....

Provided you follow the proper procedure, fully evacuate the system each time you "open" it, there will be NO issue of moisture accummulation time after time.

You can ignore my suggestions regarding engine lidsfans, etc, I have nothing to sell but fresh ideas.

So I would suggest that you first: Add an aftermarket fender mounted condensor/fan, convert to R-134a, and use the hi/lo pressure sensor as Kuehl suggests, to protect the compressor should the refrigerant ever run low, and to protect other A/C components by preventing the compressor from over-pressurizing the system.

Totally your call on the non-barrier hose issue.

But my suggestion (there we go again) would be to make that a trinary pressure switch and use the extra function to run that new fan, and maybe the front lip condensor fan, only when the system pressure warrants.

Personally (Again..??) I would also provide an after-run capability, allow those fans to run, only if warranted, for a period of time even after you turn the ignition off.

The barrier hoses will typically solve the issue on your year car as far as common leaks with the 911. If you still have an old York compressor the manifolds where the hoses connect leak often. If your condensers are in good shape and your evap, well... there is nothing left to leak. So if you are just looking for 'integrity' (no leaks) and if you still have a York, I'd suggest this as a minimum:

Kuehl 507 Comp Kit,
Complete Barrier hose set, with low-high pressure switch,
New Drier,
R134a conversion kit with ester

something like this 911 Kuehl 507 Compressor kit #3B,.
This kit would be a "turn key" solution for you, other than labor, refrigerant, evac,charge,test.
For a DIY, on the ground, figure 10 hours with common tools. You'll save a few hours
on a lift for the hose R&R procedure.

http://www.griffiths.com/shop/images...ehl507kit3.jpg


However, if you are looking for improved cooling performance, again Read The Mr. Ice Project this will also give you an understanding about your current objectives.

..... is referring, naturally, to our Kuehl Fender Condensers

http://www.griffiths.com/shop/images...uehlfender.gif

Discussed in this section of the Mr. Ice Project

"..month or so..."

Bothersome,....but...

May I suggest you convert to R-134a, and add a trinary pressure sensor/switch($20-50/parts). Use the sensor hi/lo function to control the compressor clutch just as Kuehl suggests. Then use the extra sensor function to power the front condensor fan at ALL times, even with the ignition off.

Keep track of the total cost $$$ and if this doesn't work I'll send you a check.

Why would anyone want the front condenser fan running all the time?, even with the AC system off? even with the car parked in the garage over the winter?

Funny, puzzling question for Porsche A/C, overall A/C expert/guru you claim to be.

The extra trinary switch functions, closes, ONLY when the system pressure level is above a "set" point, and then opens once the high pressure is alleviated.

Have you never walked by an unoccupied car with the radiator fan running, or even had the radiator fan start running as you walk by...? Same idea, function.

WHere is the hi/lo pressure sensor located, just in case there already is one installed on this new-to-me car?
Also, can you direct me to more details about a "trinary pressure switch", and where it would go, and how to plumb it in?