I want real A/C on my 87 3.2 - please share your upgraded system installs & reviews
 

I'm a relatively new owner of a very nice stock 87 Carrera that came with the compressor and decklid condensor in a box but all other a/c components installed. Part of what attracted me to the 87 was the knowledge that its a better starting point for someone who wants functional a/c. I bought this car to replace an Acura that I use for weekly driving. I don't drive to work but I do drive all year and need to not be sweaty in the fairly brutal, humid summers we get in CT (don't laugh if you're reading this in New Orleans or Orlando... it gets hot here). I'm willing to pay to make it right but obviously want to economize where possible. Besides adding refrigerant I'll be doing the install myself.

I've read a lot of info on 911 aircon and feeling spoiled for choice. Its clear that barrier hoses and a new compressor are no-brainers for anyone wanting 'real' a/c and the convenience of using R134. Past that all the mfgrs (rennaire, retroaire etc) have a fairly elaborate menu of options.

Here's one menu (from rennaire) totalling $700
$399 Barrier Hoses
$299 Sanden 507 compressor

I also see on their site the following and am not sure if they are required or just recommended ...

$299 ProCooler receiver/dryer
$299 Hi-eff serpentine evaporator

Retroair has a "kit" for the 86-89 cars totalling $$1610 with a Sanden compressor.

Please share your opinions and experiences!

Search for member named Kuehl. Tons of info. I believe most add an additional condenser in the left rear fenderwell among other things.

This is a good read.
Porsche 911 Air Conditioning, Porsche 930 Air ConditioningUpgrade Updates,Improvements
The owner is also a good guy that drops in here to help people that are DYI their A/C. Even those who didn't buy their equipment from him!
Cool!

My car was converted to R134a by the previous owner and it was still anemic above mid-80s which was a major factor in him selling it. I didn't recharge it after it stopped blowing cold and I really don't think I will bother with the system unless I decide to sell the car.

I like the Retroair kit, but their rear condenser won't fit cars with rear wipers. (And here in Oregon, I use the rear wiper more often than A/C.) I still haven't firmed up my parts list, but am planning on starting this soon.

GOOD read:

http://forums.pelicanparts.com/porsche-911-technical-forum/312760-adding-3-fans-rear-c-condenser.html

More....

http://forums.pelicanparts.com/porsche-911-technical-forum/345085-rear-c-condenser-fan-relay-wiring-diagram.html

And...

http://forums.pelicanparts.com/porsche-911-technical-forum/31139-cheap-air-conditioning-mod.html

Plus...

http://forums.pelicanparts.com/porsche-911-technical-forum/31134-cooler-carrera.html

It has before clear that THE major shortcoming of the Porsche factory A/C system is inadequate refrigerant condensing capacity. So, yes, the rear fenderwell condensor/fans is a good route to go....but clearly more expensive vs the obvious, inexpensive radiator fans used to more consistently provide airflow through the rear engine lid condensor.

Barrier hoses, Zimms condenser on driver rear wheel well, new dryer.

Ignore wwest. Until that guy proves with an IR temp probe pointed at a dash vent, at idle, in hot weather, than his setup will cool just as much as a modern setup - everything he says needs to be taken with a grain of salt. *Tons* of folks have gone the Kuehl route that live in hot weather (southern states), and then there is this one guy that lives in WA that added some fans and states his setup is comfortable is just as functional. You've been warned.

sub'd ! me, too!

Specifically, this is what was done with my 88: Barrier hoses, Zimms Condenser, lower evap case housing, Evaporator motor, Dryer (all done at 180k miles. Total, there was about a grand in parts, and about 1700 in labor. The rest of the parts including the compressor, are original. It blows ice cold, and honestly, almost too cold. On the hwy, I rarely have it over the warmest setting on the temp control and over Level 1 for the fan speed. In the city, it still keeps the inside cold when I'm sitting in traffic.

Center vent temps.
 

Actually, an analog thermometer is more accurate than an IR temp probe
which has a tendency to measure the duct hardware along with the air.

Here's what I and other members use:

http://forums.pelicanparts.com/uploa...1366573345.jpg

Since it is my firm belief that the singular major shortcoming is the lack of adequate refrigerant condensing capability I'm tempted to say that ONLY adding Kuehl's fender mounted condensor would suffice.

On the other hand information in one of the links has re-enforced my thought that engine heat rising up through the rear lid condensor might be the cause of long term refrigerant leakage rather than the "non-barrier" hose use.

In one of the linked threads the poster talks about actually measuring the engine cooling fin temperature once the engine is shut down. His measurements indictate that shortly after shutdown of an engine at normal operating temperature the engine cooling fin temperature rises continually for at least the next 5 minutes.

That supports my theory that the rising engine heat MIGHT cause, in ceratin specific instances, the rear lid condensor pressure to rise enough to temperarily "broad" the o-ring seals.

So, even if you decide to go with a fender mounted condensor/fan system to overcome the A/C shortcoming it might be wise to also install a fan, or two, to help cool the ENGINE once the engine fan has ceased doing its job.

Obvious that leaves us with an argument for only adding the rear lid condensor fans energized accordingly.

Use a TRINARY switch as recommended by Jim Sims. The binary section for compressor control/protection, and the 3rd function to run the new fans. Some have even suggested the usefullness of a TDR (Time Delay Relay) to provide "after-run" capability to help alleviate the risingh of engine heat. In my case the fans run in series, "half" speed, unless the compressor clutch is engaged in which case both have afull 12 volts applied.

I now plan to add the trinary switch to control the full speed mode of the fans along with a TDR to provide "after-run" (thanks to Jim Sims for the idea) if the 3rd pressure switch should remain close post engine shutdown.

Hmmm...$2700.00 when <$400.00 would have sufficed.

ac
 

I bought a partial ac kit from Griffith (Kuehl). google the site Griffiths supplies a range of air conditioning components for your Porsche 911,911s,911t,911 turbo, and 930, such as: Porsche air conditioning upgrades, Porsche air conditioning improvements and updates: Porsche barrier hoses and hose sets, Porsche c
My deck lid condenser, front condenser and the compressor were in good shape. ALL the the new hoses, evaporator, drier and The "new" serpentine rearward mounted Kuehl Condenser were shipped with fantastic installation instructions. and Charlie, the owner, was extremely patient in explaining any issues that came up during the installation.
It is lots of work...but the results were great! I will probably order a variable speed fan switch to complement it all...
I did my homework initially and chose GRIFFITHS ...others are probably good but the step by step installation instructions with photos will make your DIY life easier. Good luck

Yeah - I'm going to have to go ahead and ask you to prove that your "theories" all work as you state. You talk a lot, and to the uninformed, all this arm waving may appear to look intellectual, but you're not kidding most here. I've asked you this before, but you never respond. Why can't you find someone in the area with a fully upgraded system that you can test yours against? I mean, if you are so confident that your setup is just as functional as a $2k+ setup, then prove it. In the science community, you can't be an outlier and expect to be taken seriously without actual proof.

I did this as well. I took an additional step and added the front condenser - I was swayed by arguments that the condensing capacity of the car was poor, but I have since changed my mind on that. The fact that there were very explicit instructions in addition to good photos - seemed perfect for DIY.

As for wwest - a guy who spends so much time putting fingers to keyboard and none doing actual data collection should not be trusted as a source of any kind of expertise. And especially with respect to aircooled 911 AC systems.

Proof...

Mine has proved satisfactory in high desert areas of OR, Eastern WA, and in ID, and MT climates of 100F+

Proof of competitive adequacy in HOTlanta, TX, etc, is not so easy to come by.

So my plan is to loan, for the summer, my '88 Carrera to my nephew in Olive Branch MS. Maybe that will quiet some of the naysayers...

Even I recognize that "in the area" comparison testing with another fully Kuehl equipped 911 will not be satisfactory to most naysayers.

The fact that you'd rather ship your car to MO, and then come here to tell us "hey my relative says it blows cold air.... PROOF," makes me both roll my eyes, and frown like someone just farted on the train. Why can't you just go to a store, buy a temp prop, and find someone local? Let the cars sit for a bit on a hot day, fire them up, and see what's what. I mean, a good AC system will cool that down.

How does that seem more difficult than sending your car all the way across the country for someone else to have for a while?!

Added the front condensor AFTER installing and making use of a fender mounted condesnor/fan system?? You have OTHER problems, ask ANY of the aftermarket supplier EXPERTS.

And adding the WRONG aftermarket front lip condensor, the one that BLOCKS forward motion airflow, will yeild little improvement.

Data Collection, for the naysayers...?

My choices, as I see it.

1. Move to HOTlanta.

2. Move to Houston.

3. Heat my garage to 120F and with 98% Rh. Provide BRIGHT simulated sunlight. Buy a dyno. Buy a big enough FAN to provide wind tunnel-like road speed airflow.

Suggestions otherwise?

What city are you in? I'll find someone in your city, I'll buy and ship you a temperature prob, and you guys can go and put your cars in the sun for a bit, wait till they're nice and warm, start them, and start taking readings. Why are you so afraid to so this?

Porsche A/C
 

I have/drive a SC coupe in deep south Georgia. One hundred plus degree weather is fairly common during the summertime. I too decided to upgrade the a/c in my car, doing so over a period of several years. The first steps were to replace the York type compressor with a Sanden 507 and to replace the old hoses with home made barrier hoses. I also added a Pro Cooler at the same time as I was changing from R12 to R134. That helped a good bit, but still was not where I wanted the a/c to be. Next step was to delete the "bowtie" air diverter under the dash and replace it with an additional center vent. A bit later, I added the Keuhl end vents, again a bit better. My latest mod was to replace the front condenser with the "Desert Duty" version, replace the rear condenser with a new stock unit and to replace the evaporator core with one of the new serpentine type units. Again, better air. Most recently, I have replaced the front valence with one that has a place for a front oil cooler. Instead of moving the oil cooler there, I am thinking of moving the front condenser from it's hidy-hole spot to front center behind the airdam. There will be room also for fans for slow city driving. The other thing that I am considering doing is to put some small computer cpu fans in the ducts going to the side vents. I found some that are 12volt and are only 40mm in diameter. With the addition of a square to round adapter on each side, it will fit the existing hose size. Even without these last couple of mods, my a/c will keep the inside of my car "comfortable" but not frosty. Eventually I want to get to the "frosty" level!

Good luck with your project!

Yours is a perfect example of the snake oil salespersons selling you FIRST, slight system improvements without having you first address the core, BASE problem.

IMMHO the very first thing you should have done is buy/install any one of the fender mounted condensor/fan combined systems. I suspect, am of the belief, that had you done that initially none of the other purchases would have been a true requirement.

The ProCooler, for instance, was likely a step backward, simply making the compressor work all the harder. The only time you are likely to have "excess" refrigerant cooling capability DOWNSTREAM of the evaporator is AFTER the cabin/atmosphere has been cooling down to your satisfaction. And most of us, at that point, would be throttling back on the compressor dutycycle anyway.

Interesting. I didn't know you had airflow data for this. Could link to the post where you shared that experimental data with PP readers?

Thanks.

I did Retroaire, and although it was a new install I am quite happy with it. I ended up deviating from the plan (put vents in console, used the Porsche AC compressor mount etc), but it works well. Good parts, good support from the vendor, not so good instructions but I was able to get it to where I wanted it fairly easily. I did the charging myself (R134a).

Dennis

wwest - where do you live? I'll ship you sensors to test your car with since you seem to think it's easier to send your car across country. Why do you never respond to my comments when I say we'll get you setup with someone local?

John Walker's Workshop or Redmond European could (and does) do anything with respect to 911 AC. They could do the pressure test that answers the "overpressure" hypothesis. IIRC, Redmond European has a leak detector that could sniff the connections for refrigerant leaks. The very simple answer as to why he doesn't take to these experts is that once his hypotheses are shot down, he'll have no reason to further bash Griff. He takes great pleasure in it, obviously.

Hell, I'd help pay for all these tests.

You don't seem to understand. Here, where I reside, east side of Seattle, most days the factory A/C system will be quite adequate. Only exception might be a long commute in stop and go traffic on a relatively HOT day.

But my business of years ago required me to travel to the eastern WA, high desert area, Wenatchee, Yakima, TriCities. And...Amazingly as it may seem my wife and I both enjoy(ed) traveling (KS, NB, OK, AR, TN, MS) with the '78's Targa top stowed but with the A/C at full blast.

So I began experimenting with how to improve the A/C capability of the system.

I can't say for sure today but I suspect the kernal for my idea came from recognizing that the aftermarket availability, and obvious success, of the fender mounted condensor fan combination played a hand in my solution.

Was an additional condensor needed or would simple more consistent airflow through the existing condensors suffice..? Know that Porsche made this veru same first step in improving the A/C performance didn't hurt.

By his posts I'd guess he is in Seattle. A heat wave there is 72F with 45 minutes of full sunshine. Bingo! :D

Doesn't matter. Whenever I ask him to line up his car with another, he stops responding to me. So, anyone willing to go this far on the keyboard on literally *every* AC post, but, won't provide a lick of hard evidence, and avoids all posts asking him to demonstrate this with another car - should tell you that he's probably a bit scared what the data will say.

Were I to have a profit stream as a result then maybe.

This is place where your credibility starts to fall down. "Adequate" in Seattle would be "holy crap it's so hot in this car - WTF is up with the AC" just about everywhere else. Over here in E. WA, the stock system just can't keep up. *Even at freeway speeds*. You know, when all kinds of air is moving over the condensers. Right there, this little tested fact shoots your decklid fan mod down. Makes it moot. Puts it in the grave of half-baked ideas.

I have no doubt that in Seattle, you find very little use for AC. Heck, when I lived over there, none of my cars had AC, and I never gave it a thought. Open the windows, and presto! plenty of cool-enough air. When you start making comment about Kuehl and the aftermarket products in general, everyone but you understands that your opinion is worthless. You don't have the experience to offer an informed opinion, and you don't have the test data to verify your hypotheses. Another reason your opinion is easily rebutted. This is a technical forum - why do you constantly avoid offering test data? (Wait for it, here comes the subject change(s).)

Again, as many SOUTHERNERS have dutifully pointed out, in the climate conditions readily available to me ANY Porsche factory A/C system of the era of concern would provide A/C cooling capacity just as adequate as mine with the fan modification.

A comparitive test with a fully dressed out Kuehl system in the deep south on a HOT and HUMID August day would be the only was to quiet the naysayers, and justifiably so.

PM sent regarding Griffith's system and my experience.

WHAT? You want to make money from the deal? Someone want to pay for the test to be done, but you want the further step of lining your pocket? Unbelievable.

Here's what's to prove - that actual pressure in the system rises like you say it does. You *hypothesize* that this is where the refrigerant goes. I do not agree that your hypothesis, because others claim that you are mistaken - others that have more credibility. Now, you don't have to prove that your hypothesis is grounded in reality - that isn't what ANYONE is asking. We have been asking you to actually hook up equipment and prove, with actual testing, that what you offer as a hypothesis is actually happening. In actual reality. If the system DOES NOT behave as you claim, then your refrigerant loss hypothesis is false, you will have either form a new hypothesis or accept the already-tested solution as valid.

Your attempt to recast the question is becoming a tired tactic.

"..everyone but you.."

How about those that have added rear lid condensor cooling fans with stated

Jeepers jumpin Jehovah. It always amazes me how far sideways these threads go.

The guy just wants some useful information.

Key word. Useful.

I try to send the OP a PM to let him know what is going to happen to his thread before it gets to this point.

Has anyone ever actually tested the "hypothesis" that the refrigerant leak results ONLY from the use of non-barrier A/C hose. Used the old o-rings, connectors, etc. Has anyone, anyone, changed ONLY the hoses. And if so what was the result? High system pressures STILL resulted in leaks...??

Well, not really. My a/c system would not hold pressure very long (a few months at best), R12 was even then expensive and I did not like working around the York type compressor in the engine compartment. Knowing that I was going to swap over to R134a coolant, it was also necessary to change the non-barrier hoses and dryer. Siince I was going to replace the dryer anyway, I decided to give the Pro-cooler a shot. Changing to the Sanden compressor took several pounds off the tail of the car and made it easier to do things like adjust valves and change plugs, etc. While the first steps did not make the car as cool as I wanted, it did improve the situation noticibly. It was 2-3 years later that I did the other work. There actually seem to be two real problems with the SC a/c. The first is that there is insufficient air coming from the dash vents. The end vents especially are too small. The second problem is that the front condenser is not in the air stream. The fan that blows thru the front condenser does not move enough volume of air to do a proper job. When I got around to replacing the evaporator core and the condensers, it was largely because they had been abused over the years with lots of fin damage. As I said earlier, I will likely move the front condenser to the center of the air dam where it gets a healthy flow of fresh air and put a couple of small fans behind it to use in slow traffic. Once the two real problems are resolved, insufficient air flow from the dash vents and over the front condenser, I fully expect my a/c to work as well as in any other car.

You are being deliberately obtuse.

Nobody disagrees that your hypothesis on working fluid loss is plausible. But the difference between "plausible" and "that's what is happening" is where the disagreement comes - not because the possibility doesn't exist, but because the possibility has no data to support it. The counter hypothesis - that 40 feet of non-barrier hose fixes the leaking refrigerant problem, well there have been more than a couple of folks who have testified to that. So, they replace the hoses, and don't have to recharge their systems. I would suggest to you that this very strongly implies a problem with the hoses, and not system overpressure. But you can show otherwise by showing not only system overpressure, but leaks from the o-rings.

You shifting the burden of burden of proof from your own hypothesis to someone else's is transparent and tiresome. If the system pressures track as you say, hooking up hoses to prove it will be simple and easy. The "profit" to you, personally, is that you have actual data - so you get to shut up the "naysayers" as you so cleverly call them.

Shut up the naysayers...no hope absent 3 or 4 of them as witnesses.