Cant argue with you on this. Altho its the only intelligent and truthful thing you said, based in facts, in the entire 35 page thread filled with otherwise useless drivel... ironically, you and wwest are alot alike. both spewing speculation as fact...

This is not my 911; this 911 pictured is owned by one of my very happy front and rear matched set PFC's clients that now has a 30 degree in 95 ambient temps A/C

GET Over IT, I dumped you last year for constant changing what you told me you wanted custom made for you.

looks like you have taken over as the leader of the usless drivel here.

I am making and supplying 911 A/C PARTS AND INVENTING MORE PRODUCTS I am not the BS like many here are

Enjoy the obsolete A/C technology you bought GRIN

So no learning only flame baiting?

The configuration you picture may well be derived from one that I have been suggesting for a few years now. Even possible, given the need and simplicity of the design approach, that someone else came up with the idea strictly independently.

Assuming a "clone", the front condensor fan may have been intentionally disabled just as I suggested.

You might/will find that the 2 fans run in series, half speed, with the A/C switched on, both automatically go to full speed when the compressor clutch is engaged.

With the increased efficiency of the rear condensor resulting form the additional cooling airflow you might not need the horribly inefficient front fan anyway.

Do you have an opinion as to how well the system cools as is once the cabin is cooled down initially...?

sacoffee

Steve I have started writing a reply to you post here but am a little busy and will post it as soon as I can

Thanks West ... According to the receipts this was installed in early 2012

Never put a thermometer on it but it blows really cold ... Problem is the amount / mass of cold air output, the system cant exchange enough air to keep up 111 F heat index day like yesterday. I would love to have more volume.

The front condensor blower was frozen - took it apart tonight.

No worries - you guys obviously know your stuff and we could learn a lot.

NO clue on the compressor!

I am going to tell you straight up if you want to have colder A/C IN YOUR 911, you need to remove your old Porsche OEM Behr obsolete front and rear condensers and replace them with the newest technology condensers you can afford the more state of the art the better!!!

Porsche made a major well known A/C design flaw in the body of the early model 911’s of not having enough A/C condenser SURFACE AREA room available in the original front and rear condenser placement area’s to allow the A/C to properly work until I came along and overcame the flaw using state of the art condenser heat exchanger technologies using my custom designed and engineered for early model 911’s PFC’s.


Here is some helpful advice

For your “front fan in the trunk not working”, the first thing you need to do is to find out and verify if FAN MOTOR is getting 12 volts electricity to the fan electric motor leads and the other fan electric motor lead you need to verify it IS grounded, if this true the fan motor should work if it is not damaged/burned out.

Key switch on, A/C switch ON unless you want to start the engine which you do not have too. Also without the engine running with these switches both on you can sometimes hear a very slow turning motor maybe.

Note there is an electric A/C relay switch usually inside of “the smugglers box; WHICH IS further/deeper inside your front hood area under a hinged plate with 2 movable tabs that when slid lets you open the smugglers box in the area around the sides of your black plastic evaporator box.

Note also on top of the black plastic evaporator box the evaporator fan motor that is probably also fead electricity from the same relay as your front condenser squirrel-cage fan motor, you might have only a bad relay or loose wire?

If you determine you need to replace your front condenser squirrel-cage fan motor or your evaporator blower motor in the future if damaged, I recommend if you’re going to use Porsche OEM parts to replace either of these 2 motors because they have failed to order the Porsche 1989 model year motors because they have higher RPM fan shaft speed then prior years motor models!!!!

You can also just connect 2 wires to the battery and connect them carefully on the wire ends using alligator clips directly to the motors 2 wires and this way bypass the relay, going from positive and negative battery terminals to the positive and negative motor terminals; this will tell you right away if you have a bad electric blower motor

Note your front condenser fan is very important, mostly for A/C cooling during stop and go traffic/driving or extended idling.

Note your evaporator fan puts out the coldest A/C air temps into your cabin when the fan speed is set on lowest speed; NOT HIGH SPEED!!!!

I am not going to say much about your OEM condensers except the 2 rear deck lid condenser fans and relays are useless
I seal my PFC’s to the rear deck lid and use the engine fan because it is far more then needed


I have posted a wealth of information here if you can take the time to find and read what interests you and you will learn a lot

"...blows really cold..."

That would imply you have adequate condensing capability even without the front fan.

"..blower was frozen.."

That would imply a blown fuse. Given the circumstances the PO may have ignored....

Did not Happen. I offered to test... And I never heard from you. Too busy making crap up and quoting 20 hear old Google lab info. Nice imaginary gig you have going here...

Good god. Don't get your info from Wwest. Lol he just makes it up as he goes. Do a search.

"..use the engine fan becuase it is far more than needed.."

Isn't it pretty obvious that the above is NOT the case, even with ANY aftermarket condensor design, given the engine cooling airflow improvement Porsche did with the 964 to increase just the engine cooling capability....??

These are just amazing threads. I don't think there have been many threads at all on this board that have gone this long, and haven't been locked due to all the crap being flung at each other. And for the most part, all because of A/C, frickn classic! Super entertaining though, glad I don't have a/c in my poorscha.

Hu?! Porsche reduced engine cooling efficiency with the 964 in attempts to lesson noise - the 964, curved blade fan moves significantly less air than the earlier, 11 straingt blade fans and they added those ridiculous, heat trapping panels under the engine . . .

Move to Texas, or any other similar climate, and see if you still think that.

Oh, don't get me wrong my other car has a\c and I use it once in a while here in chicago, but this thread is nuts!

You're right about that! This reminds me somewhat of the ". . . Hurt by MotorMeister" thread. I knew from the OPs first couple of posts that this, and other threads of his, were going to be doozies as he started right of bragging/patting himself on the back about his a/c prowess while disparaging others in the Porsche a/c field. Then add on his "top secret/non disclosure agreement" verbage, repetitive pictures and text, and escalating insults and here you have it! :D

Those curved blades are used for the same reason that jet airplanes have swept wings, less air turbulence, more efficient airflow. So those 964 curved blade fans are not only quieter, but quite possibly move more cooling airflow throught the engine cooling vanes.

They move MUCH less air according to Porsche (as published in Bruce Anderson's book) and were used only to comply with noise reduction mandates. Note there is an error where 997 is used in place of 993.

http://i630.photobucket.com/albums/u...nie/img030.jpg

The facts directly from Porsche prove otherwise. I love how you go into every thread and post meaningless false crap, usually not even related to the discussion. Get a life WWEST!

Here is proof Reid in this very thread. Post #31. Get a grip man.

[QUOTE=Ronnie's.930;7515313]They move MUCH less air according to Porsche

Only some less, most of the loss is due to the pulley ratios, 1.6:1 vs 1.8:1.

(as published in Bruce Anderson's book) and were used only to comply with noise reduction mandates. Note there is an error where 997 is used in place of 993.

Turn the curved blade fan at the same rate =

Sorry, numbers don't "jell".

1500 FPM w/1.6:1 ratio = ~1333 FPM w/1.8:1, not 1210 FPM...

Regardless of "some" or "much", the point I was trying to make was that your statement that engine cooling was improved on the 964 was not accurate - the fan design, pulley ratios and under engine paneling (all implemented to reduce noise) actually lessened engine cooling efficiency.

Oh, okay....the engine cooling was only IMPROVED on an as needed, as required, dynamic. The cabin heating blower/fan was used only when needed for "make-up" engine cooling capability, and for "after-run" cooling requirements.

he doesnt get it. Its why he shows a pic of a SPAL fan on a deck condenser in which he likens it to the 993 when discussing engine heat, when the 993 didnt even have a condenser in the engine bay. so its not a valid comparison. the circular arguments are baffling.

Well, if nothing else, at least all this "off topic" blather is sure to piss Reid off - ha! :D

This thread makes me glad I did an a/c delete on my 911.;)

[QUOTE=wwest;7515389] wwest, I looked at the fan data again, and just noticed something that addresses your question in this post:

Turbo fan (which is the fan that is on most 911s from 1980 on) - 1.6:1 pulley ratio =1500 L/sec at 6000 RPM and the 964 fan - 1.6:1 pulley ratio = 1010 L/sec at 6100 RPM. Now wouldn't you say that this is a significant difference in air volume between the two (same pulley ratio as well)?

C'mon... the 964 fan only moves two-thirds as much air. Rounding error! :D

But porsche supplemented with the heater fan. LOL

all those 964 owners need is a few SPAL fans and a trinary switch.

That's too funny! Yes, Porsche's "rounding" of the fan blades was indeed an air volume error - ha! :D

Ha! I haven't looked up the L/sec to CFM conversion, but I guess you would need more than one SPAL to make up the 490 L/sec difference (and maybe a dozen trinary switches) - ha! :p

Pulleys...parallel...fishes I'm getting confused...where is Catpain Slow and his capital letters to explain this to Joe Public?

Numbers do not "jell"...

The engine pulley is always larger than the fan drive pulley.

early 911 - 1.3:1 - 1,390 liter/sec - 6,100 RPM (fan = 7930 RPM)

1976-77 - 1.8:1 - 1,265 liter/sec - 6,000 RPM (fan = 10,800 RPM)

1978-79 - 1.8:1 - 1,380 liter/sec - 6,000 RPM (fan = 10,800 RPM)

Turbo fan - 1.6:1 - 1,500 liter/sec - 6,000 RPM (fan = 9,600 RPM)

Same fan - 1.8:1 - 1,210 liter/sec - 6,100 RPM (fan = 10,980 RPM)

Shouldn't that 1,210 liter/sec be 1687 liter/sec ...???

964 fan - 1.6:1 - 1,010 liter/sec - 6,100 RPM (fan = 9760 RPM)

wwest - I guess I am too dense to understand the formula you are using to determine fan speed but it does look like there is a discrepancy for the reported 993 Twin Turbo fan output. However, I was really just noting a comparison between the most used 911 fan (the turbo) and the 964 and I assume that you agree that the 964 fan moves a lot less air at the same pulley ratio? Or are you suggesting that all of the published numbers are wrong given the apparent 993 turbo error?

There was a thread this week were a guy decided to make a 964 fan work on a 911 engine because he did not like the noise of the 911 fan. He did some type of air volume measurement and also noted that the 964 fan, even with his custom pulley setup, moved much less air (he was not concerned with this, however).

I don't wish to say one way of another but I've always been under the impression that the curved, "swept wing" blades were more efficient at moving airflow due to the lower turbulence, NOISE, factor.

Found the thread, wow..a lot of work.

He cut the 964 fan down in 2 dimensions to get it to fit the 911 shroud and still got 80% of the original 911 fan airflow rate. Makes those numbers really look suspect.

Did you also notice that he did not say what size fan pulley he made? And wouldn't trimming length off of the curved blades make them more like the straight blade 911 fan (some of the most curved portion was removed). Regardless, even after all that, it still moved significantly less air . . . I can't speak for anyone else, but I consider 20% less air flow, considering the massive volume that the fans move, to be a huge number.

But what would the fan have moved not trimmed..?