How did R134a converted systems work

[hornetball]

on the day SLC had its highest recorded temp of 107 degrees last month

In the interest of historical accuracy, SLC has reached 107 before on July 13, 2002 and July 26, 1960.

https://www.weather.gov/media/slc/ClimateBook/July%20Maximum%20and%20Minimum%20Temperatures%20with%20Normals.pdf

But, it's a dry heat.   

[V63]

Question here. We all know that some hit in performance is taken with a 134 conversion. Largely due to the R12 tube and fin condenser that isn't as efficient as a 134 spec condenser that looks like a radiator, like we find in cars today.

Here's a question, what would be the effect to add a "better" 134a condenser into an otherwise R12 system? I assume there must be some kind of gotchya or some OEM would have done this at some point.

I believe the technical advance that improved refrigeration performance was the new parallel flow condensers. The DTS 2006-11 (factory R134) system will absolutely freeze you out. Moreover the entire system seems durable having had no issues upwards of 200k mile.

In the Sonoran desert I have been 'converting' my  OEM condensers to the modern cross flow design. I am doing a 1974 right now. I utilize the original side brackets and fasten the latest 'parallel flow'  version ($140?) with in those,  that way the whole assembly mounts like OEM. I also replace all the hoses while I'm there. 

["Cadillac Kid" Greg Surfas 15364]

During the period from about 1980 through the present, with the cabin sizes have become smaller. With the additional insulation added to the vehicles (primarily for sound control), and with the correct selection of ALL components for the AC systems for the refrigerant in use (R-134a until 2013 and HFO1234yf thereafter),AND with the advent of newly developed materials and electronic technology system performance has taken an exponential leap forward.
Just like the difference between the 1950"s system and the advent of ATC in 1964, parallel progress has been made in Mobile AC systems to that of commercial and residential systems. 
Greg Surfas

[TJ Hopland]

Didn't most manufacturers change to a variable displacement compressor about the time or not long after the switch to R-134?    I'm assuming at lower RPM's the displacement increases so you get decent cooling then at high RPMs it decreases so its not overdoing it?   Lets them select a pulley ratio that gets enough capacity at idle and not blow up on the highway?   I wonder if anyone tried a CVT drive system? 

My 73 has been fine but its not 'unmodified'.  When I got the car it was missing pretty much everything from under the hood except the VIR.  Since it was all missing it seemed to me to make a lot more sense to just start over than try and replace it with original stuff.  Sanden compressor, vir eliminator, and aftermarket condenser.   It was a few years ago now but at the time I think I did the whole system including the new custom hoses for about what a replacement A6 compressor would have cost. 

Something in my EFI system seems to have got jealous of me being cool inside the car and making it extra hot under the hood so I'm currently waiting for a replacement ECU to get back on the road.

[Eric DeVirgilis CLC# 8621]

You mean a V8-6-4 compressor?    That's too much...ha

[TJ Hopland]

I'm sure someone at least had one designed on paper.   I have no idea how they work,  I assume they are more like hydraulic pumps where there is a mechanism that varies essentially varies the stroke. 

[smokuspollutus]

I believe the technical advance that improved refrigeration performance was the new parallel flow condensers. The DTS 2006-11 (factory R134) system will absolutely freeze you out. Moreover the entire system seems durable having had no issues upwards of 200k mile.

In the Sonoran desert I have been 'converting' my  OEM condensers to the modern cross flow design. I am doing a 1974 right now. I utilize the original side brackets and fasten the latest 'parallel flow'  version ($140?) with in those,  that way the whole assembly mounts like OEM. I also replace all the hoses while I'm there.

I think the same thing. No complaints whatsoever about 134 in modern cars that were designed for it. Even the ones from back in the changeover period that to my knowledge were otherwise the same minus the condenser. '92 Park Avenue with factory R12 and '94 Lesabre with 134a, they both would become uncomfortably cold. The two cars were almost identical with the Park Ave being just a little bigger.

The parallel flow condenser seems like a good upgrade to make considering that its largely invisible on most cars being hidden under the radiator top mount (71-76 notwithstanding...)

Question is, all else equal, would a parallel flow condenser help even an R12 system?