AC R12 to R134a Upgrade
 

I upgraded my 1989 911 Carrera Cabriolet OEM AC from R12 to R134a using Griffith's Kuehl evaporator, receiver/drier, barrier hoses and added rear wheel condenser. Now my car blows 38 degrees at idle from the center vents and 35 degrees down the highway. These temps were recorded last week here in Phx AZ on a 117 degree day with 17% humidity. The OEM R12 system never blew below 60 degrees. The kit from Griffiths was very detailed and I did all the install myself and took it to my Porsche mechanic (Don Jackson Ent.) to charge. They hooked it up to their fancy Snap-on machine and 39oz and 30 minutes later it was done! I wish I had done this years ago. Anyone else have similar experiences?

Welcome to the board! Gotta post a pic of car, though. Unwritten rule. :)

Many many stories here of big step-change success with Griffith's stuff.

A/c
 

I did most of the above, but limit my center duct temp to 40f in
order to prevent evaporator freeze-up in our high humidity region.

I set the temp controls to:

40f-OFF.

52f-ON.

Best,

Gerry

I also did the major upgrade using Griffith's Kuehl parts:
- new same as R12 compressor with clutch
- added 2 fender condensers
- new Griff front condenser
- all new Griff hoses, lubed the O-rings with Superlub
- variable fan speed controller
- LED control indicator
- new accumulator
- hi/low pressure switch controlling the clutch wire
- new evaporator, thermo switch and exp. valve
- flushed compressor mineral oil out using the PAG MasterChem Ultra Pag 46 Premium Double End Capped PAG oil. Viscosity ISO 46 oil and filled with same PAG oil - I think I used 5.5 OZ or so.

Blows about 39-42F on hot days.
Some assembly required. :-)

I've had and continue to have the same experience. And have not needed to charge it and it's been 2 yrs easy.