JDM A/C Facts & Findings
#1
JDM A/C Facts & Findings
In my quest to make my car compatible with the HKS V-Mount a/c lines, I've dug really deep into the JDM a/c parts catalog. I don't have everything concrete and i'm not sure I ever will but hopefully this will help someone in the future.
My car: 1992 build FD, chassis 114381.
A/C Components on my car and their comparison to USDM parts
Compressor: Is marked DENSO. R12 fill. The lines that mate to the compressor on my car also mated up to a USDM R12 Denso Compressor. Quite possible you can use a USDM compressor on this early JDM chassis.
Drier: Not DENSO. I purchased a UAC drier part # 1225C cataloged as a RX7 Denso drier and it will not work with the 1992 lines. The line going into the drier does have the sight glass, however.
Lines: These will be specific to the early JDM chassis, due to RHD orientation and line/fitting sizes. It may be possible to use a US line from the compressor to condenser, or drier to condenser but that's it.
Condenser: I was sold a USDM DENSO condenser from tomsn16, this condenser matches the condenser from my 1992 perfectly. Lines screw in, everything bolts up the same.
Pressure Switch: The JDM 1992 and 1996 switches are identical, I do not have a US switch to compare.
Evaporator: This will be JDM, and early JDM specific due to the RHD orientation and line/fitting sizes.
R134 JDM A/C Components and how they compare to the early/R12 Components
R134 appears to have been installed in mid 95 & later JDM models. Besides the pressure switch, and the electrical components attached to the evaporator, none of these parts will cross over to the early JDM model. Its all or nothing. Every line/fitting is a different size and/or type, similar to the differences between USDM MANA and DENSO systems.
HOWEVER, parts are still available for the R134/late model systems in Japan. I was able to purchase a few lines brand new, a brand new condenser, and compressors are available as well. I will be installing an entire JDM R134 system in my car and so far everything will work. The only question left is the evaporator which I will report back on later.
Why did I go through all this trouble to make my car fit a few lines vs making a few lines fit my car? I'm stubborn, and I like tinkering. I wanted everything to bolt and work as OEM. If I need a replacement for anything it is somewhat easy to get and no need to have another custom line made or whatever the case. Plus its all designed to use R134, which is also readily available.
If you have any questions feel free.
My car: 1992 build FD, chassis 114381.
A/C Components on my car and their comparison to USDM parts
Compressor: Is marked DENSO. R12 fill. The lines that mate to the compressor on my car also mated up to a USDM R12 Denso Compressor. Quite possible you can use a USDM compressor on this early JDM chassis.
Drier: Not DENSO. I purchased a UAC drier part # 1225C cataloged as a RX7 Denso drier and it will not work with the 1992 lines. The line going into the drier does have the sight glass, however.
Lines: These will be specific to the early JDM chassis, due to RHD orientation and line/fitting sizes. It may be possible to use a US line from the compressor to condenser, or drier to condenser but that's it.
Condenser: I was sold a USDM DENSO condenser from tomsn16, this condenser matches the condenser from my 1992 perfectly. Lines screw in, everything bolts up the same.
Pressure Switch: The JDM 1992 and 1996 switches are identical, I do not have a US switch to compare.
Evaporator: This will be JDM, and early JDM specific due to the RHD orientation and line/fitting sizes.
R134 JDM A/C Components and how they compare to the early/R12 Components
R134 appears to have been installed in mid 95 & later JDM models. Besides the pressure switch, and the electrical components attached to the evaporator, none of these parts will cross over to the early JDM model. Its all or nothing. Every line/fitting is a different size and/or type, similar to the differences between USDM MANA and DENSO systems.
HOWEVER, parts are still available for the R134/late model systems in Japan. I was able to purchase a few lines brand new, a brand new condenser, and compressors are available as well. I will be installing an entire JDM R134 system in my car and so far everything will work. The only question left is the evaporator which I will report back on later.
Why did I go through all this trouble to make my car fit a few lines vs making a few lines fit my car? I'm stubborn, and I like tinkering. I wanted everything to bolt and work as OEM. If I need a replacement for anything it is somewhat easy to get and no need to have another custom line made or whatever the case. Plus its all designed to use R134, which is also readily available.
If you have any questions feel free.
The following 3 users liked this post by AE_Racer:
#2
RX-7 Bad Ass
iTrader: (55)
Have you had a chance to see the differences between the JDM 134 compressor and the US R12 compressor?
Nice work!
Dale
Nice work!
Dale
#3
I was able to swap the evaporator this afternoon.
JDM 1992 R12 Evap on the left, JDM 1996 R134 evap on the right. Plug and play in the car. The connector plugs right in, same wire colors. Two bolts hold it in. Drop the glovebox completely, 2 screws. One nut on the very top of the evap and one at the very bottom. Super easy for an evap swap.
The difference is in the lines. JDM 1992 R12 on the left, JDM 1996 R134 on the right. Again, the R134 evap will plug and bolt in to the car but the R12 lines will not work.
JDM 1992 R12 Evap on the left, JDM 1996 R134 evap on the right. Plug and play in the car. The connector plugs right in, same wire colors. Two bolts hold it in. Drop the glovebox completely, 2 screws. One nut on the very top of the evap and one at the very bottom. Super easy for an evap swap.
The difference is in the lines. JDM 1992 R12 on the left, JDM 1996 R134 on the right. Again, the R134 evap will plug and bolt in to the car but the R12 lines will not work.
Last edited by AE_Racer; 08-15-19 at 07:24 PM.
#4
JDM 1992 R12 Compressor vs JDM R134 Compressor (year unknown, assume 96-97).
Again, the lines are not compatible between the two. However, they bolt to the car the same, the electrical plug in is the same, the clutch and pulley are the same.
R12
R134 compressor, pics stolen from DaleClark. Its already in the car, forgot to take pics I have seen pictures of a few other compressors with the matching 442500, followed by -4570 and -4572. Those looked identical to this one.
Again, the lines are not compatible between the two. However, they bolt to the car the same, the electrical plug in is the same, the clutch and pulley are the same.
R12
R134 compressor, pics stolen from DaleClark. Its already in the car, forgot to take pics I have seen pictures of a few other compressors with the matching 442500, followed by -4570 and -4572. Those looked identical to this one.
Last edited by AE_Racer; 08-15-19 at 07:28 PM.
#6
RX-7 Bad Ass
iTrader: (55)
Nice. Hope you can get the AC up and going!
I really should have cleaned that compressor before I took pics .
Dale
I really should have cleaned that compressor before I took pics .
Dale
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y0ungjoker (10-13-19)
#9
May I ask where you acquired any of the JDM A/C components?
#11
Juris Doctor
iTrader: (3)
So I wanted to add to this thread... as my friend @AE_Racer and I came to find out on my car...
It appears the 1993 JDM RX-7 came factory R134a. Came to find this out after having to replace the drier and the expansion valve on the evaporator. Turns out if you order 1993 USDM RX-7 parts, you are going to get R12 variants and the ports will not work. If you order any year with the R134a, you are going to get it to work. Also, the expansion valve is interchangeable with a number of other cars... namely a Lexus ES300. Turned out to be a Denso Expansion valve #447500-0031. I was able to source it looking under Lexus at a local auto parts store. Our A/C Thermoswitch that sits on the evaporator also is interchangeable with early Mazda MPVs. I'll do a bit more digging, but looks like it may have also been used on a number of other Japanese brands/models. So even when you think a part is no longer available for the RX-7... it might just be the same part for a newer car.
Anyways... now my A/C is working like new again and its so cold even in stop & go traffic with the Florida heat of 90-95 degrees... I still have to turn the fan setting to 2 unless I'll freeze.
It appears the 1993 JDM RX-7 came factory R134a. Came to find this out after having to replace the drier and the expansion valve on the evaporator. Turns out if you order 1993 USDM RX-7 parts, you are going to get R12 variants and the ports will not work. If you order any year with the R134a, you are going to get it to work. Also, the expansion valve is interchangeable with a number of other cars... namely a Lexus ES300. Turned out to be a Denso Expansion valve #447500-0031. I was able to source it looking under Lexus at a local auto parts store. Our A/C Thermoswitch that sits on the evaporator also is interchangeable with early Mazda MPVs. I'll do a bit more digging, but looks like it may have also been used on a number of other Japanese brands/models. So even when you think a part is no longer available for the RX-7... it might just be the same part for a newer car.
Anyways... now my A/C is working like new again and its so cold even in stop & go traffic with the Florida heat of 90-95 degrees... I still have to turn the fan setting to 2 unless I'll freeze.
The following users liked this post:
DaleClark (07-02-21)
#12
Full Member
Did the evaporator construction look much different between the R12 and R134a versions? I've got an early JDM car as well which I'll have to piece together an AC system for as most of it is missing... I remember reading somewhere that many cars which moved from r12 to r134a also changed the evap construction as the R134a has a lower specific heat?
I've got an R134a compressor in a box somewhere I can swap on, just hoping the evaporator / expansion valve will be all good? Don't want to have to muck around sourcing those parts. I can make / have made the lines, no to stressed about that.
I've got an R134a compressor in a box somewhere I can swap on, just hoping the evaporator / expansion valve will be all good? Don't want to have to muck around sourcing those parts. I can make / have made the lines, no to stressed about that.
#13
Juris Doctor
iTrader: (3)
@ZacMan if you are just changing the compressor, you shouldn't have to worry about the rest of the system. It will just be converted to run R134a versus the R12. I can tell you that the evaporator and everything else in the system is different between the R12 and R134a cars due to the port sizing. All the JDM cars were Denso units so you won't have to worry about sourcing MANA parts.
#14
Hey...Cut it out!
iTrader: (4)
So I wanted to add to this thread... as my friend @AE_Racer and I came to find out on my car...
It appears the 1993 JDM RX-7 came factory R134a. Came to find this out after having to replace the drier and the expansion valve on the evaporator. Turns out if you order 1993 USDM RX-7 parts, you are going to get R12 variants and the ports will not work. If you order any year with the R134a, you are going to get it to work. Also, the expansion valve is interchangeable with a number of other cars... namely a Lexus ES300. Turned out to be a Denso Expansion valve #447500-0031. I was able to source it looking under Lexus at a local auto parts store. Our A/C Thermoswitch that sits on the evaporator also is interchangeable with early Mazda MPVs. I'll do a bit more digging, but looks like it may have also been used on a number of other Japanese brands/models. So even when you think a part is no longer available for the RX-7... it might just be the same part for a newer car.
Anyways... now my A/C is working like new again and its so cold even in stop & go traffic with the Florida heat of 90-95 degrees... I still have to turn the fan setting to 2 unless I'll freeze.
It appears the 1993 JDM RX-7 came factory R134a. Came to find this out after having to replace the drier and the expansion valve on the evaporator. Turns out if you order 1993 USDM RX-7 parts, you are going to get R12 variants and the ports will not work. If you order any year with the R134a, you are going to get it to work. Also, the expansion valve is interchangeable with a number of other cars... namely a Lexus ES300. Turned out to be a Denso Expansion valve #447500-0031. I was able to source it looking under Lexus at a local auto parts store. Our A/C Thermoswitch that sits on the evaporator also is interchangeable with early Mazda MPVs. I'll do a bit more digging, but looks like it may have also been used on a number of other Japanese brands/models. So even when you think a part is no longer available for the RX-7... it might just be the same part for a newer car.
Anyways... now my A/C is working like new again and its so cold even in stop & go traffic with the Florida heat of 90-95 degrees... I still have to turn the fan setting to 2 unless I'll freeze.
Bottom line is that FDs built in July 1993 will be R134 no matter where in the world you are. It's roughly akin to "94 spec" here in the US.
#16
RX-7 Bad Ass
iTrader: (55)
94 RX-7's in the US had R12. 95's had R134a.
95 is when it became mandatory in the US. This makes sense that they changed it earlier for the Japanese cars with a different government mandated switch over.
Also remember '94 and '95 is model year, they were built and sold earlier than that.
Dale
95 is when it became mandatory in the US. This makes sense that they changed it earlier for the Japanese cars with a different government mandated switch over.
Also remember '94 and '95 is model year, they were built and sold earlier than that.
Dale
#18
Hey...Cut it out!
iTrader: (4)
94 RX-7's in the US had R12. 95's had R134a.
For comparison, my first car was a 1995 Mitsubishi Mirage (built 11/1994). This generation (93-96 in the US, 92-95 in Japan, production began in 10/1991) made the jump to R134 for US model year 1994 as well. Coincidentally, airbags were also phased in starting in 1994 for driver and 1995 for passenger side. Since this was their ecobox model, it got airbags last while a higher-end model like the FD or GTO (3000GT) would receive all the new "toys" first, all despite being in advance of the 1996 requirement for airbags in the US.
Anyway, back to the matter at hand. Realistically speaking, to do a retrofit in a R12 car the correct way, it sounds like line adapters for using the R134a Receiver-Drier and Compressor, and O-rings for each connection are all that's needed.
#19
RX-7 Bad Ass
iTrader: (55)
My '94 R2 has R12 from the factory, no questions about it. All '94's I've ever seen have had R12.
Many US cars had the AC system installed at the port in the US, the "MANA" AC system.
Dale
Many US cars had the AC system installed at the port in the US, the "MANA" AC system.
Dale
#20
Hey...Cut it out!
iTrader: (4)
Got a feeling the very first thread here was "Why does my a/c suck?"
Anyway, once I'm finished with the Eunos Cosmo, I'll be turning my attention to the FD in order to give this proper attention.
#21
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Join Date: Dec 2017
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I'm so glad that I came across this thread. I recently moved to Florida and my JDM FD should be getting sent here soon. I've been on the hunt for info for the A/C system because it's never produced cold air in the 3+ years I've owned it and I just now started looking into my options. Any idea on the pricing for buying the 93+ system from Japan?
#22
RX-7 Bad Ass
iTrader: (55)
It can be tricky finding RHD AC parts from what I understand.
Hands down the most common problem with AC is a leak. You really need to figure out where it's leaking first to know what you need to fix or buy. A good AC shop should be able to sort that out quickly.
Dale
Hands down the most common problem with AC is a leak. You really need to figure out where it's leaking first to know what you need to fix or buy. A good AC shop should be able to sort that out quickly.
Dale
#23
Sorry to re-open this thread.
But it is the service ports also in different location for JDM? I read that on USDM they are by the turbo side, but mine, 1993 JDM, seems to be on the intake elbow side.
Can anyone confirm?
But it is the service ports also in different location for JDM? I read that on USDM they are by the turbo side, but mine, 1993 JDM, seems to be on the intake elbow side.
Can anyone confirm?
#25
In my quest to make my car compatible with the HKS V-Mount a/c lines, I've dug really deep into the JDM a/c parts catalog. I don't have everything concrete and i'm not sure I ever will but hopefully this will help someone in the future.
My car: 1992 build FD, chassis 114381.
A/C Components on my car and their comparison to USDM parts
Compressor: Is marked DENSO. R12 fill. The lines that mate to the compressor on my car also mated up to a USDM R12 Denso Compressor. Quite possible you can use a USDM compressor on this early JDM chassis.
Drier: Not DENSO. I purchased a UAC drier part # 1225C cataloged as a RX7 Denso drier and it will not work with the 1992 lines. The line going into the drier does have the sight glass, however.
Lines: These will be specific to the early JDM chassis, due to RHD orientation and line/fitting sizes. It may be possible to use a US line from the compressor to condenser, or drier to condenser but that's it.
Condenser: I was sold a USDM DENSO condenser from tomsn16, this condenser matches the condenser from my 1992 perfectly. Lines screw in, everything bolts up the same.
Pressure Switch: The JDM 1992 and 1996 switches are identical, I do not have a US switch to compare.
Evaporator: This will be JDM, and early JDM specific due to the RHD orientation and line/fitting sizes.
R134 JDM A/C Components and how they compare to the early/R12 Components
R134 appears to have been installed in mid 95 & later JDM models. Besides the pressure switch, and the electrical components attached to the evaporator, none of these parts will cross over to the early JDM model. Its all or nothing. Every line/fitting is a different size and/or type, similar to the differences between USDM MANA and DENSO systems.
HOWEVER, parts are still available for the R134/late model systems in Japan. I was able to purchase a few lines brand new, a brand new condenser, and compressors are available as well. I will be installing an entire JDM R134 system in my car and so far everything will work. The only question left is the evaporator which I will report back on later.
Why did I go through all this trouble to make my car fit a few lines vs making a few lines fit my car? I'm stubborn, and I like tinkering. I wanted everything to bolt and work as OEM. If I need a replacement for anything it is somewhat easy to get and no need to have another custom line made or whatever the case. Plus its all designed to use R134, which is also readily available.
If you have any questions feel free.
My car: 1992 build FD, chassis 114381.
A/C Components on my car and their comparison to USDM parts
Compressor: Is marked DENSO. R12 fill. The lines that mate to the compressor on my car also mated up to a USDM R12 Denso Compressor. Quite possible you can use a USDM compressor on this early JDM chassis.
Drier: Not DENSO. I purchased a UAC drier part # 1225C cataloged as a RX7 Denso drier and it will not work with the 1992 lines. The line going into the drier does have the sight glass, however.
Lines: These will be specific to the early JDM chassis, due to RHD orientation and line/fitting sizes. It may be possible to use a US line from the compressor to condenser, or drier to condenser but that's it.
Condenser: I was sold a USDM DENSO condenser from tomsn16, this condenser matches the condenser from my 1992 perfectly. Lines screw in, everything bolts up the same.
Pressure Switch: The JDM 1992 and 1996 switches are identical, I do not have a US switch to compare.
Evaporator: This will be JDM, and early JDM specific due to the RHD orientation and line/fitting sizes.
R134 JDM A/C Components and how they compare to the early/R12 Components
R134 appears to have been installed in mid 95 & later JDM models. Besides the pressure switch, and the electrical components attached to the evaporator, none of these parts will cross over to the early JDM model. Its all or nothing. Every line/fitting is a different size and/or type, similar to the differences between USDM MANA and DENSO systems.
HOWEVER, parts are still available for the R134/late model systems in Japan. I was able to purchase a few lines brand new, a brand new condenser, and compressors are available as well. I will be installing an entire JDM R134 system in my car and so far everything will work. The only question left is the evaporator which I will report back on later.
Why did I go through all this trouble to make my car fit a few lines vs making a few lines fit my car? I'm stubborn, and I like tinkering. I wanted everything to bolt and work as OEM. If I need a replacement for anything it is somewhat easy to get and no need to have another custom line made or whatever the case. Plus its all designed to use R134, which is also readily available.
If you have any questions feel free.