SL/R107: Improving AC performance
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Joined: Feb 2017
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'73 450SL
Improving AC performance
[B]the summers get to hot here for my AC unit in my '73 450SL to be effective. i want to improve the performance of my AC with a modern compressor. will that do it and what's involved besides purchasing a modern compressor?[/B]
MBWorld Fanatic!
Joined: May 2015
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From: Miami, FL
2003 CL 600
Nope. The system will never be as cold as the new cars are, the efficiency is just not there. Also, that system was designed for R12, and is probably using R134 now. 134 operates on a higher pressure differential as it's not as efficient, so the older system loses some cooling power when using the newer refrigerant it wasn't designed for.
To fully modernize it you would have to change the expansion valve and would need to update the condenser/evaporator if you wanted to get any noticeable cooling effect increase. Also, old cars aren't nearly as airtight as newer cars, so it's much harder to get the inside cool when you lose your cold air to the outside and get hot air in.
Enjoy the car for what it is, if you need freezing cold a/c, buy a new SL.
To fully modernize it you would have to change the expansion valve and would need to update the condenser/evaporator if you wanted to get any noticeable cooling effect increase. Also, old cars aren't nearly as airtight as newer cars, so it's much harder to get the inside cool when you lose your cold air to the outside and get hot air in.
Enjoy the car for what it is, if you need freezing cold a/c, buy a new SL.
Member
Joined: Feb 2018
Posts: 97
Likes: 17
From: Gold Canyon, Az.
1988 560SL, 2017 SL 450, and a few Corvettes
Another thing that you can do to help keep the car cool is to insulate under all the carpeting, especially on either side of the transmission tunnel, where it does radiate heat, just like it does on classic Corvettes.
