A/C upgrade
 

I am looking to upgrade the a/c in my '76 911. It currently has the dealer installed unit from VPC. It is missing the condensers and the compressor. I am looking into the rotary vane compressor and kit from Performance Aire in Ca. Does anyone have any advice or info about this. Thanks.

i upgraded my 78SC York to a Sanden It Is a good improvement got the complete kit with bracket from Zims Aototeknic in Tx for 270.00
even though the Sanden is not a true rotary it uses 1/3 the hp of the York . the compressor isnt what makes the car cooler it is just a pump what these cars need is more condensor to dissapate heat my car has the single deck condensor and the air doesnt work very well past 105' here in Vegas but its better than nothing Id skip he rotary i hear there less reliable go for the Sanden and work on adding more condenser

I have the Sanden upgrade in my 78 911. This compressor has a good reputation among Porsche owners, but I'm not really thrilled with mine. The compressor is really loud at idle, and even louder with engine under load, which shouldn't affect the ac compressor at all. It quiets down at speed. I've considered the possibility that engine movement torsionally could be causing belt rubbing, but I've gone so far as to have a friend drive the car slowly while I sit on the bumper looking for problems, and everything looks ok. My Sanden compressor makes a noise similar to a failing 5 speed transmission with a chipped gear. It could be that I got a defective compressor, or more likely I have a problem elsewhere in the a/c system.

My advice to you- since you are rebuilding your system, replace the expansion valve and the reciever/ dryer. Get new hoses made at a local a/c shop (should cost $15-$50 per hose instead of $200 each from the Porsche retailers). Assemble the system yourself if you feel up to it, then have a quality shop that knows Porsche evacuate and charge the system. Vertex Automotive (305 442 2727) offers the rear condenser for your car for $175, the Sanden upgrade kit is $280.

My 87 Carrera is out of freon. Has anyone changed to the 154 fluid. If so is anything other than changing to non permeable hoses and a new dryer involved. With the way Summers are now would be tempted to put in tne bigger condenser that Performance Aire is offering.Has anyone done that? Thanks, Ned

Serge
Your compressor shoudn't make any noise or vibration. My new Sanden makes a slight whisper noise at idle thats all.Before replacing my compressor my mounts were loosewhere the compressor mounts to the motor if you can grab your compressor and move it at all you may be missing some bolts etc. Also did they add oil to your system low oil may cause a noisy compressor if not any of these symptoms id have them replace the compressor

I ordered my Sanden from Vertex, and I did everything myself, which could be the problem. My compressor mounts are very tight. you can shake the whole car by grabbing the compressor. I have a vacuum pump and manifold gauges, and did my own evacuation and charging, which may have voided my warranty, I don't know. I don't think I did anything wrong, after I installed the compressor, two new hoses, a new dryer and belt, I evacuated the system at 29 in vacuum for 30 mins. Then I added 30 oz of r134a, and 8oz of ester oil. I guess my next step is to change the expansion valve, since mine is old and they're pretty cheap. By the way- I've been told that to convert to r134 from r12, you must dissasenble and flush the whole sytem, because 134 and 12 use incompatible types of oil. Since I replaced so much, I didn't do this. It cools really well, I'm out of money, so I guess I'll live with it for now. If I learn anything else of interest I'll post here.