Quote:
Originally Posted by Chevy3+3
I will say that almost 15 yrs ago we converted a '78 chevy to 134a and use the original condenser and it would FREEZE you out! I would probably rate it as being on of the coldest a/c systems I have ever driven.
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That's how my 79 is with a stock system converted to 134. We've driven that all over Arizona in the heat. Last year 117 outside we made a trip to Tucson and the AC system was freezing cold, turned the fan down. Truck doesn't even have tinted windows. Huge front grill area and extremely large condenser with a mechanical fan and A6 compressor.
I've done tons of these conversions, including a lot of my own stuff on vastly different cars with some experimentation.
I had an 88 Iroc Z, R4 compressor that I converted to 134. It was okay but never ice cold, but that car is a bottom feeder with no grill opening and very difficult to get airflow through the condenser/radiator area.
2 years ago we converted my sons 89 5.0 Mustang, complete stock system with it's sanden style looking compressor, switched to 134. Now this system will freeze you out of the car, and it's a completely black mustang, very hot in the AZ sun yet it cools down quickly. But it has a better grill opening in the front and a decent size condenser, along with a clutch driven mechanical fan that is always moving, so the system works well.
My 72 blazer has factory AC. Here's an interesting experiment. When original with it's A6 compressor, converted to 134 it would do an excellent job of cooling the truck, considering a blazer has a rather large area inside to cool. I later swapped a 6.0 LS engine and at the same time did a dual electric fan setup and switched to a Sanden compressor (no bracketry for an LS to accept the A6 so I was forced in this situation) Back up and running, now the AC system was subpar in my opinion. It worked okay but not as well as it did with the old A6. The AC system is so large on these trucks I have to believe that little sanden just wasn't capable of moving the Freon as well and the performance suffered as a result (it's the only variable in the system)
I've found AC performance is really dependent on the car in question, the size of the condensor and the compressor make a huge difference in these deals. All of the retro conversion I do come with the parallel condenser but these retrofit systems are very small. Some work okay if there is enough grill opening but some suffer. 57 Tbird I just did has a vintage air system with a very tiny parallel condenser and a pusher fan to help and a sanden compressor. Even in the tiny 2 seater passenger compartment the system will barely keep you comfortable. It only held 19 ounces of Freon before the pressures were where they needed to be, it's just too small of a system to do the job effectively, even the parallel condenser isn't making the grade in this application, it's just not large enough and the car isn't big enough up front to accept anything larger.
Tons of other examples but you can see the trend....