Why so many 911 with disc. air ?

rfaust6024 · 10-04-2009, 12:48 PM

Having just recently purchased my first Porsche (77 911 with 86 3.2 engine and 930 kit) I really know very little about the 911's but am now starting to notice things here and there from all the pics I'm looking at here on this site both in for sale section and forums that the air conditioning pump is either missing or has had the fan belt disconnected. Why is this? Isn't air a good feature to have? Are there problems with it?
Thanks,
Robert Faust
Redwood City, CA

Venetian · 10-04-2009, 12:53 PM

Do a search. You could read for a week on this issue.

p911dad · p911dad's Garage

My ol' 84 Carrera has had more trouble with the A/C than any other system over the many years I have had this car. I think that the system was grafted onto an old existing design instead of ever being part of the original plan. Who could have imagined a car designed in the early 1960's would still be manufactured in 1989? So- folks in warm areas like most of the US wanted air and Porsche delivered- a cobbed up system. Not like good old GM with millions of units each year each blowing ice cold air, having a whole division just to perfect A/C, little Porsche had to make due with what it had. Many owners just give up. I have changed the compressor twice and along with hoses and a condensor have a pile into it. And it lately has yet died again.
Just make sure that fan belt you are talking about is still connected to the fan, as that cools the engine and also operates the alternator. Losing that can be fatal to the engine(you would get a warning light on the dash if that occured).

kidrock · 10-04-2009, 05:27 PM

the phrase of "ice cold air" and "Porsche" is like the phrase "Military Intelligence".

paulgtr · paulgtr's Garage

it adds weight complexity and and saps power...

HarryD · 10-04-2009, 06:05 PM

Quote:

Originally Posted by rfaust6024

Having just recently purchased my first Porsche (77 911 with 86 3.2 engine and 930 kit) I really know very little about the 911's but am now starting to notice things here and there from all the pics I'm looking at here on this site both in for sale section and forums that the air conditioning pump is either missing or has had the fan belt disconnected. Why is this? Isn't air a good feature to have? Are there problems with it?
Thanks,
Robert Faust
Redwood City, CA

As another noted, AC is an afterthought on cars up to at least 1989. There are several reasons for this. On as the other poster alluded is that Porsche is not GM (who invented and perfected car AC) and then there is the whole packaging issues. Unlike most cars, the AC lines are very long (bad for coolant flow) and it is hard to get enough air over the condenser due to the limitations of where you can get a clean air flow. Add to that the loss of power, you see many of us bag it and move on.

FWIW, my '73 came with "factory air" but at a cost of about $2,000 why fix it when I only need it for a few weeks here inthe north west. If I still lived in Houston, I would have a different attitude.

fintstone · fintstone's Garage

You can upgrade the AC so that it works pretty well...but it is not inexpensive. Personally, I would not drive a car without A/C that works...especially a 911.

dw1 · 10-04-2009, 06:44 PM

In summary:

1) It doesn't work all that well because of the "add on" nature of the factory system, and the location of the evaporator(s).

2) It adds weight, and power-to-weight ratio is what makes performance. One could add HP, or subtract weight. Guess which one is easier (up to a point...)

gestalt1 · 10-04-2009, 06:58 PM

acouple nice things about the 911 is that because the engine is behind you there is actually less heat getting in the car as would happen on a front engine car. additionally the front wing windows help prevent too much wind buffeting with the windows down at highway speeds. unless you live in a hot humid climate and need to wear a suit to work the missing AC really is not a big deal.

HarryD · 10-04-2009, 07:02 PM

Quote:

Originally Posted by gestalt1

acouple nice things about the 911 is that because the engine is behind you there is actually less heat getting in the car as would happen on a front engine car. additionally the front wing windows help prevent too much wind buffeting with the windows down at highway speeds. unless you live in a hot humid climate and need to wear a suit to work the missing AC really is not a big deal.

I will add that here in Portland, I find that many of the days I need to run AC in my Windstar or Focus, the 911 is warm but not uncomfortable. I chalk that up to the fact that:

1-The 911 was designed when AC was not widespread and the designer had to ensure that you could get good air flow in the car without excessive noise (newer car have a lot of buffetting when you open the windows at speed); and
2-I have the little movable wing windows to catch a breeze and direct it to where I need it.

tcar · 10-05-2009, 07:55 AM

I see the wing windows guys have early cars; those only existed for about the first 10 years.

The last 15+ years of that body had none, and needed them.

In some climates, lack of A/C really limits driving for more days than not.

My '78 with R12 and bowtie removal (with additional vent) was great, even on 100 degree days, but it's drier here than Houston.

scottrx7tt · 10-05-2009, 09:03 AM

i guess i was lucky. I bought my car back in march. The pevious owner gave me a bunch of spare parts, one was the original york compressor. He removed it because the AC did not work. I put the compressor on, replaced the receiver/dryer, and expansion valve, ran a vacuum on the system, and shot it with some freeze12. I have never seen vent temps above 45 degrees from the vents, even in the hottest most humid days. It is essentially a completely stock system, with the exception of the freeze12.