Hi Phat, my understanding is that all compressors are Denso Tv12 series between NA and NB. The differences are minimal and more importantly, a 90-93 R12 car will require 94-97 R134a suction/discharge flex lines to properly seal. I found this out the harder way when attempting to use a compressor out of 97' in my 91' Yukimura. as soon as pressure builds ,it will blow the o-ring as the clearance was excessive. I stayed with 90-93 R-12 compressors as the result( however charged system with R134a)

On the other hand, I did manage to reduce the drag the compressor present to the engine: the manual I have claims that 5oz of PAG100 oil is needed and instead of doing that, I gave the system 4qt of PAG100 and 2oz of ICE32 friction reducer. I also intentionally undercharged the system with only 16oz of R134a to reduce peak high-side pressure. Resulting in :ambient temp 95 degrees F, ac setting at "2", Idling, vent temperature-44 degreeF. Moving, 30mph or higher speed, the vent temp can reach 40 degrees F or lower! All while largely reducing engine drag since the high pressure side is only 150-170 psi. Far better then my original 20oz R134a charged system when I bought the car 2 years ago that could reach 220-250 psi, and never gets very cold.

Quote Originally Posted by Phatmiata View Post
Charles, make sure to post this info in your build thread on here so it does not get lost, it took me a good bit to find this thread again.

Anyhow, I am wondering since you did this have you considered swapping out the NA Compressor for an NB compressor? Its a superior design because of its higher efficiency (specifically designed to R134-a refrigerant ) vs our older and (converted) NA6/8 cars. This would be a great advantage due to having less engine load, and its a lighter weight too!! (I was told the NB version is 11-lbs lighter) All you NA6 guys know what im talking about too, kick on the A/C and you loss engine power right away!

I know they are doing these swaps in Japan now because finding OEM NA parts in good used condition is becoming hard to find as they export most of their old cars. Cars are considered a "Classic" in Japan in only 10 years so it becomes expensive to keep a classic car there, vs here in the USA where we don't get a classic title until 20 years, and there are no extra costs/fees to keep a classic here in the USA vs Japan.