512TR AC question | FerrariChat

512TR AC question

Discussion in 'Boxers/TR/M' started by JIMBO, May 8, 2025.

This site may earn a commission from merchant affiliate links, including eBay, Amazon, Skimlinks, and others.

  1. JIMBO

    JIMBO Formula 3
    Silver Subscribed

    Oct 31, 2003
    1,348
    Bradenton, Florida
    Full Name:
    Jim DeRespino
    I just finished optimizing the AC on my '94 512TR. It will blow 38 degrees at the center vent while driving at 60 mph, but if I stop for a light or have traffic, it barely cools. At idle with a large fan in front of the car I can get 68 degrees. I replaced the compressor, condensor fans, drier and trinary switch at last service 4000 miles ago and flushed all the lines. New expansion valve 15,000 miles ago.
    Ester oil in compressor.

    There is a slow leak, requiring one can of refrigerant every summer. Yesterday I vacuumed the system down to -29 for 30 minutes, and then let it sit for another hour - it held steady at -29. I added just under 2 lbs of Freeze-12 (R12 replacement) and had low side 40 and high side 210, which has always worked well in the past. 30 minutes later both sides equalize out to ambient temp (80).

    What can I do to improve performance? More refrigerant? The condensor fans come on appropriately. Everything seems to be working. Is this just the best performance I can expect in a 31 year old Ferrari without R12 in this car? It's a small cockpit to cool but a lot of windshield and black leather exposed to the Florida sun (windshield is tinted to reduce heat and UV).

    Any suggestions would be appreciated.
     
  2. Steve Magnusson

    Steve Magnusson Two Time F1 World Champ
    Lifetime Rossa

    Jan 11, 2001
    26,580
    30°30'40" N 97°35'41" W (Texas)
    Full Name:
    Steve Magnusson
    Can only say that those two statements do not agree at all. Have you, or can you, put a hand in behind the condensor fans to "feel" if there is a reasonable amount of airflow (and it should be rather warm if the AC is "on")? I.e., when you say "the condensor fans come on appropriately" are you just judging that by the sound or by the airflow?
     
  3. JIMBO

    JIMBO Formula 3
    Silver Subscribed

    Oct 31, 2003
    1,348
    Bradenton, Florida
    Full Name:
    Jim DeRespino
    The condensor fans are both new and they both come on together by the sound. I have not put my hands back there.
     
  4. Steve Magnusson

    Steve Magnusson Two Time F1 World Champ
    Lifetime Rossa

    Jan 11, 2001
    26,580
    30°30'40" N 97°35'41" W (Texas)
    Full Name:
    Steve Magnusson
    Does that mean "new and stock" or "new substitutes"? These should be fairly kick-ass fans.
     
  5. Rifledriver

    Rifledriver Three Time F1 World Champ

    Apr 29, 2004
    36,816
    Cowboy Capitol of the World
    Full Name:
    Brian Crall
    Our 90 TR in Texas never has the A/C set at full cold and I am never uncomfortable. The 512 in my opinion has a better condenser design .
    But ours is white and I use nothing but real R12.

    Slow leaks in the system are a no extra charge feature of Ferrari due mostly to the garbage hoses Ferrari uses. With 134a retaining freon is hopeless.
     
    EZORED and dgt like this.
  6. rumen1

    rumen1 Formula 3
    Owner

    Jun 23, 2012
    1,813
    Bulgaria
    The 512TR has a very strong A/C in my opinion. It is hard to adjust it to the exact temperature you need it to blow, but if we are talking about power and cold, I think it is a very strong unit.
     
    EZORED likes this.
  7. JIMBO

    JIMBO Formula 3
    Silver Subscribed

    Oct 31, 2003
    1,348
    Bradenton, Florida
    Full Name:
    Jim DeRespino
    Brand new versions of the original style fans
     
  8. JIMBO

    JIMBO Formula 3
    Silver Subscribed

    Oct 31, 2003
    1,348
    Bradenton, Florida
    Full Name:
    Jim DeRespino
    I'll probably go back to real R12, although in the past the Freeze-12 has been much more effective. I'll try adding some more coolant first.
     
  9. ago car nut

    ago car nut F1 Veteran
    Silver Subscribed

    Aug 29, 2008
    5,471
    Madison Ohio
    Full Name:
    David A.
    EPA out-lawed R-12, Most older HVAC techs liked the R-12 better than R-134. Rumor is they want to out law R-134 soon. The residential R-22 is gone, you can't even retrofit the older units with the new freon. Whole new unit needed. Condenser and A-coil. The EPA likes to stick it to consumers. How much really are we saving the planet?
     
    turbo-joe likes this.
  10. Rifledriver

    Rifledriver Three Time F1 World Champ

    Apr 29, 2004
    36,816
    Cowboy Capitol of the World
    Full Name:
    Brian Crall
    #11 Rifledriver, May 15, 2025 at 8:29 AM
    Last edited: May 15, 2025 at 8:35 AM
    If you think R12 is expensive you should see what the replacement for R134 costs.
    Newer freons are all just incremental improvements and its odd how a mandated replacement happens only after the patent rights on the previous version expires.
    If they were serious about freon being released in the environment they would require higher quality components that reduced unintended releases like hoses and seals. But requirements are only made when it allows for higher profit for the industry.
     
    lagunacc and ago car nut like this.
  11. ago car nut

    ago car nut F1 Veteran
    Silver Subscribed

    Aug 29, 2008
    5,471
    Madison Ohio
    Full Name:
    David A.
    EPA contacted Du-pont chemical about developing a more eviro friendly freon to replace R-12. Dupont replied, it won't sell. EPA maid it mandatory, made R-12 disappear. Dupont had the royalty license rites on all R-134. Everyone had to pay Dupont to produce it. Just like the post above. All this save the planet is BS. for profit.
     
    lagunacc and turbo-joe like this.
  12. tbakowsky

    tbakowsky F1 World Champ
    Consultant Professional Ferrari Technician

    Sep 18, 2002
    19,856
    The Cold North
    Full Name:
    Tom
    The Testarossa/512TR are not refrigerators. You may simply be asking far too much from an old system. That said, how much refrigerant and you pumping into the system? You may not be adding enough. I usually fill to 1.75lbs, which will usually set the high and low sides where they should be. It should be able to bring the cabin to a comfortable temp. However...that angled front windshield is a real bugger to fight..
     

Share This Page