Carrera Stock A/C OK, Even in Phoenix

[RandalJ]

I will have had my '86 Targa two years this September. Just wanted to share my observations on the stock A/C, and how it has coped with the Arizona heat.

When I thought about getting a 911, I knew full well the reputation for less than stellar air. Still, I decided to take the plunge and hope for the best. This car was going to be my daily driver (my wife has a Honda Pilot, so we are not totally dependent on my car).

Having bought the car in early September (actually on 9/11!) of 2002, there was only another month or so of hot weather. I don't remember being too bothered by the A/C. I think I was mainly getting the hang of the car, and by the time October rolled around, the A/C didn't matter.

Come spring of 2003, it definitely wasn't putting out. I figured it needed charge (kidding myself that the leak was a slow one, or might even go away). Turned out that the R12 was slowly leaking out the compressor. I bought a new compressor, and eventually a new low-pressure side long hose (the return from the front to the compressor).

What I remember of last summer is that when not leaking and fully charged, the A/C was more than adequate up to about 107 ambient, in full sun. Unfortunately, most of last summer was spent finding the next leak and re-charging. But at least I knew that if everything was fixed, the A/C would be adequate. I probably ended up spending $1000 all told. I decided to stay with R12, believing it to be more efficient than R134a, and figuring the 911 system needs every edge you can give it. So, much of that cost was for $60 cans of freon.

This summer, the system was leaking again, but this time the leak was around a hose crimp that was done by the shop the previous year - so they fixed and re-charged for free.

So, I think everything is finally sorted out. I have now been driving for four weeks, and the air out the vents is still ice cold - even at the high fan speed.

It appears to me that if you have everything set up right and operating properly, the stock system works pretty well, even in Phoenix.

My disclaimer here is that my commute is relatively traffic-free. My opinion would probably be different if I regularly had to sit in bumper to bumper traffic for any length of time, because then I'd probably have to shut down the A/C to prevent engine overheating.

And if temperatures start heading past 110, and they will, the A/C will probably be marginal at best, no matter what the traffic. We'll see.

But all in all I'm satisfied with it. I'd also say that as 911s go, dark colored (mine's Prussian blue) targas (all that glass in the back is like a greehouse), and the relentless sunshine of Phoenix are expecially challenging to the A/C system. Fortunately I have the bigger vents that came with the '86 and later model years.

So, my message is, if you live in any other locale, you might be better off bringing the stock system up to snuff instead of spending thousands on a custom system.

One other side note for the archives - I tried replacing my A/C temp switch/thermostat/probe. As far as I know, there are no replacements that fit. I bought a replacement from Pelican, who got it from Porsche. The replacements are slightly too tall and don't fit in the console. Apparently Porsche doesn't even know this. I called Griffiths to ask what they use. They were not cooperative. I ended up repairing my original, since it just needed a housing repair.

[rzepko6194]

I just used my A/C for the first time since buying my 87' Carrera Targa last November. The outside temps were about 87 degrees, nowhere near the 107 degrees in Phoenix but with fairly high humidity.

The A/C worked pretty well even with the blower speed on high. My system is stock with R12 refrigerant.

I'm still planning on adding a Griffiths Kuehl vent just to push a bit more air. I also plan to replace the coolant lines with barrier types next winter. I have to make sure my stash of R12 lasts a long time! ;-)

[FenderGuy]

RandalJ good to know that Phoenix heat doesnt sway the 911 ac . Looking foward to my own 911 in summer driving here soon

[Steve W]

Mine works pretty well too here in L.A. No complaints. I've got the small early vents, and all stock. All I did was eliminate the lower bowtie vent, and install a Performance Aire bowtie diffuser, along with porting a second hole from the plenum into the cabin, as per their directions. Made the biggest difference - tons of air volume.

[Por_sha911]

Originally posted by rzepko6194
I also plan to replace the coolant lines with barrier types next winter. I have to make sure my stash of R12 lasts a long time! ;-)

You may want to research this but, I've been told that AC lines won't leak with R12 because the oil used with R12 will naturally plug the "holes" (unless the line is old and cracked).
Any experts want to verify or destroy what I've heard?

[993.986.]

Wow, that's great news. The previous owner of my 87 Targa converted to the R134 refrigerant and it's not really up to the task above 85 degrees (yeah, the only time you really need it). Maybe I'll switch back after reading this.

[yogi]

I have an 87 coupe with the stock ac system running on R12. I'm suprised at how well my ac works here in South Florida. I was warned before I bought the car that Porsches ac do not work real good. I did add a center Kuehl vent to help air flow. Sometimes when I get out of the car after using the ac my glasses fog up from the temperature and humidity change.

[Jim Sims]

Talked to my son an hour ago; he's 100 miles west of Needles, California out in the Mojave desert. The A/C system we added to his '73T could freeze him out (he had to turn it down) this afternoon on I-40. It consists of '76 vintage KCoool evaporator and fan with booster fan pushing air into the evaporator, Performance-Aire three-pass engine deck lid mounted condenser and a new Sanden compressor. Running R-134a refrigerant in new barrier hoses with a boost from a subcooler mounted above the front steering gear splash pan. Subcooler takes advantage of the heat of vaporization of liquid that made it through the evaporator to precool (subcool) the liquid refrigerant going to the expansion valve in the evaporator. Cheers, Jim