A/C upgrades (R134) - Operation Chill

Piratetip

Far From Maddening Crowds
Staff member
Super Moderator
Authorized Seller
Joined
Dec 30, 2005
Messages
1,620
Likes
142
Location
MKE, WI
#82
Youre right, I was wrong.
I recommend that everyone not evacuate their systems and pull -29 psi before refilling.
 

Piratetip

Far From Maddening Crowds
Staff member
Super Moderator
Authorized Seller
Joined
Dec 30, 2005
Messages
1,620
Likes
142
Location
MKE, WI
#84
I have recently bought the guage set and have used the vacuum pump from Autozone, so servicing things will be easy enough. Just really more about not wanting to go thru a bunch of trial/error, if there's a known component that will improve the A/C's performance when using R134.
I assume everyone does the wrong thing on this forum unless they indicate otherwise.

After searching this thread over I see my lapse in judgment in this case.

Although this post was nowhere near the end of the thread.
 

Satan

Active Member
Authorized Seller
Contributor
Joined
Mar 31, 2005
Messages
1,599
Likes
0
Location
Tampa
#86
^^I pulled vacuum for about 50 minutes and then let it hold for another hour, before adding the freon. I screwed up tho and forgot to close the low-side valve when switching to the 2nd can of freon.

I've heard that once it runs through the system a bit, it's supposed to get better (maybe colder)? Did not see anything substantiating the statement, so don't believe it to be true. At the next oppty I have to refill, I will certainly pay attention to closing the valves when I am supposed to.

I'll post the product specifics in a bit, so that others can order and installl successfully. I am also doing a last-ditch effort towards volume pricing.
 

jetjock

creepy-ass cracka
Authorized Seller
Contributor
Joined
Jul 11, 2005
Messages
9,439
Likes
2
Location
Redacted per Title 18 USC Section 798
#87
How did you come up with that charge amount? What blower speed was the 42 at? What vent? Recirc or fresh? High and low side pressures after stabilization? Coolant valve on there and working?

At 75 ambient (what RH?) you're not asking much of the system. I'm not saying it won't work when warmer but there are ways to tweak it if it doesn't.
 

grimreaper

New Member
Authorized Seller
Joined
Jul 2, 2008
Messages
2,180
Likes
0
Location
Dallas
#89
How did you come up with that charge amount? What blower speed was the 42 at? What vent? Recirc or fresh? High and low side pressures after stabilization? Coolant valve on there and working?

At 75 ambient (what RH?) you're not asking much of the system. I'm not saying it won't work when warmer but there are ways to tweak it if it doesn't.
How can you know that it is heatsoak that is affecting the H/L pressures? and not an overfill issue?

Should the pressures sit stable at idle? I have a huge floor fan i can stick in front of it but that seems like cheating to get accurate readings. 95 degree ambient measured at 2" in front of condenser. High side will rise (225psi) until the ac fans kick on and drop it down some (idle). Low side sits around 28-30psi.

r12, vent temps at 42 with recirc on after 10-15 minutes of city driving, measured at medium fan speed at the left center vent.
 
Last edited:

jetjock

creepy-ass cracka
Authorized Seller
Contributor
Joined
Jul 11, 2005
Messages
9,439
Likes
2
Location
Redacted per Title 18 USC Section 798
#90
Those numbers look OK. Since R12's temp/pressure curve is fairly flat a suction pressure of 30 psi means the stuff is close to 30 F which is what it should be with a working expansion valve. Keep in mind the evap isn't allowed to go below freezing or it'll ice up. Add the typical 10 degree or so drop across the evap (after all shouldering a heat load is it's job) and you get around 40-45. I'd say your system is working well.

Pressures should be stable at a fast idle/2000 rpm which is where systems are usually checked. The fan is a good thing...techs will use one to stabilize a system for performance tests. High side will change and is less important than low side as long as the system is working. A general rule of thumb for R12 is high side should be about 2.2 times ambient measured near the condenser face.

There are better ways to determine optimum charge than weight especially in a converted system. Superheat for example. There's a point where picking things apart isn't worth it though. Remember, in spite of the technical minutiae one can get into about this stuff, all that matters is "cold" ;)
 

Satan

Active Member
Authorized Seller
Contributor
Joined
Mar 31, 2005
Messages
1,599
Likes
0
Location
Tampa
#91
When charging, I just went by guage readings and low was sitting at about 28psi and high was at ~230psi... I kept filling 'til I got to as close to "normal" settings as described in the TRSM, for an R12 system.

When I added the next new cans, I purged the line, so am sure that I did not entirely use the 26 or so ounces of freon in the system. That's just how many ounces I used in the process (about 26oz). My target/intent was near 24oz, since that's what the Toyota retrofit instructions called for (650 grams of freon).

EDIT lubricant info:
I used PAG 46. I had drained the compressor before and did it again (turning the insides about 20 times, to allow more oil to drain).

I am using an Aristo A/C compressor, which already used R134, so I did not have much incompatible oil. I used the PAG 46 instead of Ester, in case there is some leftover old lubricant in the evaporator or other areas of the system.

As tested:

R134, vent temps at 41.8 with recirc on after 10-15 minutes of city/hwy driving, measured at high fan speed at the left center vent.

In addition, I am missing the lower A/C pipe that takes air to the left-most vent on the driver's side. So, I was losing a large volume of air which was flowing directly to my feet and it felt very cold too :biglaugh:

I should have another vent-pipe thing arriving soon and will retest when I have it on, to see if there's any difference.

Overall, I am VERY pleased with the results. I think that those who are seeing good temps from their R134 converted stock/serpentine condensors may be because they are newer or in extremely good shape. Whereas a beat-up, opened-up system may have taken it's toll on the efficiency of the condensor and therefore poor results when a R134conversion is done. Unfortunately, the 2 times I've had mine done (2 diff. MKIIIs), the results were poor and unpleasing.


So, before you go R134, either KNOW that your condensor is perfect, or replace with a parallel-flow condensor for "guaranteed" results (cold-@$$ air).
 
Last edited:

grimreaper

New Member
Authorized Seller
Joined
Jul 2, 2008
Messages
2,180
Likes
0
Location
Dallas
#92
Those numbers look OK. Since R12's temp/pressure curve is fairly flat a suction pressure of 30 psi means the stuff is close to 30 F which is what it should be with a working expansion valve. Keep in mind the evap isn't allowed to go below freezing or it'll ice up. Add the typical 10 degree or so drop across the evap (after all shouldering a heat load is it's job) and you get around 40-45. I'd say your system is working well.

Pressures should be stable at a fast idle/2000 rpm which is where systems are usually checked. The fan is a good thing...techs will use one to stabilize a system for performance tests. High side will change and is less important than low side as long as the system is working. A general rule of thumb for R12 is high side should be about 2.2 times ambient measured near the condenser face.

There are better ways to determine optimum charge than weight especially in a converted system. Superheat for example. There's a point where picking things apart isn't worth it though. Remember, in spite of the technical minutiae one can get into about this stuff, all that matters is "cold" ;)
cool, thank you jj!
 

jetjock

creepy-ass cracka
Authorized Seller
Contributor
Joined
Jul 11, 2005
Messages
9,439
Likes
2
Location
Redacted per Title 18 USC Section 798
#93
Welcome Grim. Note what I said is for a TXV system. CCOT (orifice tube) systems will be different. And it's funny how the AC questions pop up every year about this time :)

Satan: Once the car cools down try it on low fan. I'll bet the longer residence time puts it into the 30s...
 

CyFi6

Aliens.
Authorized Seller
Joined
Oct 11, 2007
Messages
2,972
Likes
2
Location
Phoenix
#94
Of course a lower fan setting is going to give you lower temps... all you are doing is extracting less hot air from the cab. Thats not a real test though. According to all the reading i have done you should have proper vent temps at high fan speed, upper vents only, recirculate, idle, and measure the temp at the center vents. Hell with my serpentine condenser idling on a hot day i could probably achieve close to 35 degree vent temps on low fan setting.
 

jetjock

creepy-ass cracka
Authorized Seller
Contributor
Joined
Jul 11, 2005
Messages
9,439
Likes
2
Location
Redacted per Title 18 USC Section 798
#95
I never said it was a good test, just making a point. And maybe my memory is slipping but I seem to recall your system doesn't work well. Considering your frequent proffering of advice on the subject I find that strange...
 

CyFi6

Aliens.
Authorized Seller
Joined
Oct 11, 2007
Messages
2,972
Likes
2
Location
Phoenix
#96
I never said any of it was good advice, always just making a point.. lol.. jk. It seems almost every time i comment on something you said you take it personally, i don't know why, but im not trying to say that what you said is wrong, inaccurate, or anything like that so please don't take it as such.

Something I did when i was testing out my AC, is i took a temperature thermocouple and stuck the end of it through the foam insulation directly after the evaporator core and used that as a temperature readout. That way I could see exactly what the evaporator temps were doing and anything affecting temp downstream such as the heater core or vent doors would not show up. Just an idea if you think you could have a problem elsewhere.
 

Satan

Active Member
Authorized Seller
Contributor
Joined
Mar 31, 2005
Messages
1,599
Likes
0
Location
Tampa
#97
Finally got some pricing, but still not as good as I'd hoped.

They did offer free freight (to 1 location) if 30 units are ordered. Cost is $125 each condensor, which would tie up almost $4K and a bit of my time for shipping. I could have it shipped to someone else with more time. Still a decent price, considering not having to change lines or other fabrication to make 'em fit.

I am still getting more details and trying to bring that price down a bit. I will also need to get with the admins of the different forums to make sure I get approvals and stay within whatever the guidelines are out there.
 

figgie

Active Member
Authorized Seller
Contributor
Joined
Mar 30, 2005
Messages
5,314
Likes
19
Location
Twin Cities, Minnesot-ah
#98
Satan

what type of vacuum pump did you use?

41.9, that is nice and chilly but the real test is during the hot weather. If it cools that good during, say a 90+ degree day. Then you are GOLDEN!
 

Island_Yota

New Member
Authorized Seller
Joined
Aug 5, 2008
Messages
264
Likes
0
Location
Vancouver Island
#99
My A/C is completly rebuilt and converted.. except the previous owner bought a used condenser and it leaked, Wouldnt mind replacing that and getting it recharged. Anyone know where to get one for cheap? I dont want to throw a wack of money at it only to find out it leaks somewhere else.
 

Satan

Active Member
Authorized Seller
Contributor
Joined
Mar 31, 2005
Messages
1,599
Likes
0
Location
Tampa
Dunno what the stock one goes for, but the parallel flow one discussed in this thread is at $155 top end, maybe $125 each if 30 are purchased.

Dunno what a stock serpentine one goes for from Toyota.
 

92nsx

Supramania Contributor
Authorized Seller
Contributor
Joined
Sep 30, 2005
Messages
2,957
Likes
1
Location
Clearwater, MN
Something is wrong in your system. I run r134 sine 1997. Measured temp outlet = 40 degrees on a 92 degree day with 30% humidity as measured at the vent.
Figgie is one of the few that i have seen report such good performance with r-134 on a stock system.
Im not sure where you guys are at in this conversation but I just had my OEM system charged up with R134 and it blows nice and cold. We first pulled a vacuum (fixed one leaking oring) then put a can of R134 oil converter stuff in then put in around 1.32-1.35 lbs of R134. Proof is in the pic ;) When I put the probe in it was at 42 degrees, by the time I turned on the camera and turned on micro, the compressor was already kicking in and out and went up to 45, still nice and cold.

I guess that is 2 of us now grim, maybe it is the air in Minnesota and we can just do it correct :biglaugh:

 

Satan

Active Member
Authorized Seller
Contributor
Joined
Mar 31, 2005
Messages
1,599
Likes
0
Location
Tampa
I can speak for at least 2 conversions which did not perform well for me (those were professionally done at shops... national chain).

I am glad thet there are a few of you who've had success on the 1st try, but I still do not think it's the result that many can expect.

Also, even when servicing the A/C system and NOT converting, you need to be sure that your condensor is perfect. I've heard of the build up of junk that gets trapped in most condensors, etc.

This upgrade does seem to have worked for me and even this AM, the interior temp was at 74F degrees and dropped to 45F almost immediately. After about 5 minutes of driving, it was at 38.5F.... It balanced out and remained at 41ish, until I got to work. I am sure the outside temp was probably below 80F.

Much better than any of the previous conversions in my other MKIIIs
 
Last edited:

Satan

Active Member
Authorized Seller
Contributor
Joined
Mar 31, 2005
Messages
1,599
Likes
0
Location
Tampa
PURCHASING INFO!

Please be sure to ask for your specific year, etc, since their response below is for my '91.

The company is American Condensor. I believe they are in Cali, so if you read this early enough, some of you may be able to have them start making yours as early as Monday.
_______________________________________
Here's the info for you to order directly:

Person I've worked with for mine is -

Adriana Miera adriana.miera@americancondenser.com

She said that she'd be okay with individual purchases. Did not say if they would be at what I paid, or less.

I have not made any group buy arrangements, I paid $155 plus shipping for mine, dunno what they will quote you. When you contact Adriana you can tell her Elvis sent you. Maybe if they see enough interest, they'll honor the group buy price ($125), or some other discount.

This what they got me:
Part number P39293P (it fits all the 91 Toyota supra models including the turbo).

Condensor: Parallel flow it... will just take us a few days to manufacture. If you have any questions feel free to call (310) 327-8600.

Fine print:
If it doesn't work for you, it's not my fault. I am merely passing on my findings. If you're not happy with the install or results, please don't blame me for it. Everyone has different expectancies and this modification has met mine, but may not meet yours.
 

gtsfirefighter

SM Expert on White trash
Authorized Seller
Contributor
Joined
Sep 26, 2006
Messages
2,964
Likes
3
Location
Paradise, Texas, United States
I had all the o rings and gaskets replaced right before Houston and flushed, refilled with r134. The system was already converted when I bought it but my dumbass opened the system when I pulled the engine. Anyway, I'm pretty pleased with it. I have yet to put a thermometer to it but it's been keeping me comfortable. I do notice at idle and stop and go traffic there is quite a difference in temp from cruising but nothing to make me break a sweat yet. Usually though, I don't run the a/c in stop and go situations.

A ton of good info here. If my system dies I'll go this route. Maybe this thread should be stickied?
 

sneakypete

Regular Member
Authorized Seller
Joined
Jul 18, 2007
Messages
1,129
Likes
0
Location
Central NJ
Dunno what the stock one goes for, but the parallel flow one discussed in this thread is at $155 top end, maybe $125 each if 30 are purchased.

Dunno what a stock serpentine one goes for from Toyota.
ill be down for one. im sure you can find enough people if you had the time
i would help set it up, but i dont have the money to throw down
 

grimreaper

New Member
Authorized Seller
Joined
Jul 2, 2008
Messages
2,180
Likes
0
Location
Dallas
Im not sure where you guys are at in this conversation but I just had my OEM system charged up with R134 and it blows nice and cold. We first pulled a vacuum (fixed one leaking oring) then put a can of R134 oil converter stuff in then put in around 1.32-1.35 lbs of R134. Proof is in the pic ;) When I put the probe in it was at 42 degrees, by the time I turned on the camera and turned on micro, the compressor was already kicking in and out and went up to 45, still nice and cold.

I guess that is 2 of us now grim, maybe it is the air in Minnesota and we can just do it correct :biglaugh:

bring it down here where it actually gets hot with some humidity and well see how it does in 20 minutes of rush hour traffic ;)
 

92nsx

Supramania Contributor
Authorized Seller
Contributor
Joined
Sep 30, 2005
Messages
2,957
Likes
1
Location
Clearwater, MN
What was ambient?/ were you idling with the fan on high vent on recirc?
Ambinet was only around 75 degrees, idleing with the a/c set to 65 without recirculation on.
Edit: after reading some of the threads, The vacuum was pulled down to 26-27 in/hg if that make any differance

bring it down here where it actually gets hot with some humidity and well see how it does in 20 minutes of rush hour traffic ;)
Sounds good, you provide the beer ;). BTW It gets plenty warm and humid up here too.

Once It get warmer out I can stick the thermostat back in and get some more pics for you guys.

I am still fully confident that it will work just fine and cool me this summer. Even in my last 89 that I ran R134 in, it also cooled me off without any problems, but we will see how it performs.
 
Last edited:

CyFi6

Aliens.
Authorized Seller
Joined
Oct 11, 2007
Messages
2,972
Likes
2
Location
Phoenix
was driving around last night when it was around 81-82 degrees out, r134a was blowin a nice 45-47, though earlier that day around 103-105 degrees outside with all the heat coming off the street etc i was getting around 60 degree vent temp..
 

tissimo

Stock is boring :(
Authorized Seller
Contributor
Joined
Apr 5, 2005
Messages
4,247
Likes
8
Location
Melbourne, FL
bring it down here where it actually gets hot with some humidity and well see how it does in 20 minutes of rush hour traffic ;)
Its not horrible. My car is fine, probably blows ~ 50 after it cools (a few minutes of driving). Its still very comfortable with the sun beaming on you (no tint) here in FL, even sitting in traffic.
 

chrgd89

New Member
Authorized Seller
Joined
Nov 28, 2005
Messages
26
Likes
0
Location
Leander TX
What oil do I use Pag 46 or ester oil for a new compressor? Iv heard 1 or the other from different people.
 
Last edited: