C4Scott

I'm also not converted on my 89 but did get it fully charged and tested with no stated leaks.

However, if it gets above 84 or so the AC can't keep the car cool enough. I also have the rearac blasting as well. With the temps hitting triple digits I can't even think of driving it sadly.

It my first summer with a 928 is this just something inherent to their old AC systems not meant for this heat? I know old air cooled 911s had crappynac but doesn't make sense for the 928 I thought.

Lizard928

Clean the evap core. You likely need a new expansion valve and a few other parts too.

GregBBRD

Yeah, the most trusting source of information is our government. I always check there, first! Especially with the agency that "brought us" these laws.

They "sort of ignore" that Mt. Pinnatubo "continued emmisions" alone amount to 700 tons of Bromine and 10 tons of iodine....annually. That's the equivalent of 56,000,000 pounds of Chlorine.

And that is just one "natural source".

Don't drink the Koolaid.

Tom. M

it's obvious you have contempt for the EPA ..but if you dig beneath the politics..you'll find scientists from all walks..all professions (engineers, geologists, chemists, physicists)....that do their job and do it well...try not to listen to Rush too much and drink that "Kool-Aid" too...

The research identifying CFC as a problem goes far beyond just the EPA and the science behind "climate change" is there too...take a look....I'm not going to go into a diatribe about anthropogenic effects...I'll stick to the topic at hand... Should I run R12..or R134 in the GT... believe it or not.. I'm planning on R-12...because that is what Porsche intended for my GT in 89...and I can still get it here locally (as well as off ebay)....so that is what goes in there

dr bob

The AC system on the car is very robust, with excessive capacity designed in from the start. Porsche had previously enjoyed very limited success with factory AC on their air-cooled cars, and determined from the start that their luxo-GT car would have state-of-the-art climate control capability right from the beginning. If your car can't keep up at ambients greater than 84ºF, you still have a some hidden capacity you aren't using.

My car came to me 15 years ago, 22k on it, with a pile (note: bigger than a stack) of dealer receipts for AC services since new. "Evacuate system, charge, check for leaks, none found." Even without leaks, somehow it would puke a charge in a couple months. After a few of my own recharges, it was glaringly apparent that there might be a few small leaks. I bought an electronic leak detector and went after every connection. Plastic bag wrapped around the connection, sniffer probe in the bag, so it could detect leaks down into the grams-per-year range. There were a few connections that didn't leak. Since virtually every connection and hose had to be disassembled and resealed, it made sense to do all the connections. flush the system, flush the compressor, new R-134a-compatible drier and expansion valves, etc. Reloaded the system with the correct oil (polyolester) for R-134a, with consideration that it will also work with R12 if the R-134a performance is inadequate. Evacuated the system with my gonzo pump overnight, charged with R-134a, and never looked back. I add a can of R-134a every few years, to make up for losses through the compressor shaft seal when the car sits idle for extended periods. If I drive it and run the AC regularly (monthly or better), no need to add any refrigerant.

The rest of the system is functioning well, with the vacuum diaphragms replaced and a tight heater control valve. Cleaning the evaporator is on my summer projects list, more prophylactic than remedial as the system performs flawlessly.

GeorgeM

That's a pretty good price for cans. Agreed that the price has dropped a touch. Then there's always those that think it's gold and try to get $50/can.

I'm determined to keep mine on R12, and since I replaced my leaking rear evap, it appears to be holding. I even bought an R12 recirc machine on CL for $100 and the guy threw in 20lbs of R12 for an extra $40, so I'm set for a while.

If you intend to stay w/R12, recommend getting your MVAC 609 license so you won't have issues buying it.... $25 and you can take the test online.

Good luck.

SQLGuy

Hey! I'm listening to disc 3 of Different Stages right now, and it's good stuff. Just because some people don't like Geddy Lee's voice is no reason to go calling them anti-environmentalists and stuff...

;-)

GregBBRD

My contempt does not start/stop with the EPA. I'm sure that there are great people working there that are very bright.

The political people that "control" those people are the problem.

Like probably the huge majority of Americans that actually work for themselves and are not "supported" by the wealth that we create (read government employees of any type and anyone that is collecting "socialistic dollars"), it is to the point where our contempt reaches out to all the agencies that are controlled by "politics".

We, simply put, have no more dollars left to "support" the "rest" of the country. The "gig" is over...they've finally wasted all the money that there is...or that there is ever going to be.

But enough politics. Back to the subject, at hand.

You will be much happier with R12 in your system that R134. Even with R12, the system's ability to properly cycle freon, on a hot day, is marginal.

Tom. M

Interesting Greg...I thought I took public roads to your shop and used your public water supply when I got a drink and I'm guessing you are probably on the "grid" to get power to run your shop..... but yea..I guess you guys that work for yourself don't get much benefit from the taxes that are stolen from your wages..

Considering that it's already 110ish in Kansas....I hope the R12 will be somewhat up to the task..