So I have struggled getting really freezing cold AC in my 86.5 Supra for about 4 years now. Living out in the AZ dessert seemed to take a toll on my stock AC system. I went through it multiple times making sure everything was 100% perfect, and even still it struggled. I did a lot of research and finally mustered up the money to upgrade everything as much as I possible could. Beyond what I've done there is nothing I can think of to upgrade it any further.
First thing I wanted to do was upgrade the condenser to an aftermarket parallel flow unit. The stock condenser is serpentine which is a decent design, but not quite as efficient at releasing heat as a parallel flow of the same size. The parallel flow has smaller channels for the vapor refrigerant to travel through allowing it to release more heat faster. American Condensers is the only company that makes a drop in parallel flow condenser for our cars.
My car didn't have a pusher fan stock, and the line configuration was such that the suction line in front of the condenser was smack in the middle of the condenser. If I wanted to use an electric pusher fan, I would have to swap the line to the model that has the right bends to allow a pusher fan to fit. Unfortunately, almost all the lines are different, so it wasn't a matter of swapping just the one in front of the condenser. I had to change the hardlines along the firewall and all the lines in front of the condenser. The only lines that could remain unchanged were the flex lines off the compressor. So I got lines from a donor car and flushed them out to get any old oil or debris out.
To take it a step further, I wrapped all the suction lines with insulation foam. This will keep any ambient and engine bay heat out of the suction lines which would make more work for the condenser.
Next thing on the list was the evaporator core. The pre 89 Supras use a serpentine evaporator, whereas the 89+ Supras use a plate/fin evaporator. Just like the condensers, the plate/fin is a more efficient style of evaporator and removes heat from the air more efficiently. I got a donor unit from another Supra, but it was covered in oil and had a leak. I bought a brand new Denso evaporator and thermal expansion valve to replace it. I had to use the plastic evaporator box from the 89+ to fit the plate/fin evaporator in place. The pre 89 evaporator box will not work with an 89+ evaporator. Along with the new evap and TXV, I got a new Denso reciever dryer, which should be replaced any time the system is opened up.
Finally, I bought a 10" Spal pusher fan. I have used Spal fans in the past and have been very happy with them. Spal makes fans for OEM applications and the aftermarket units are on par with OEM quality. This fan is from the "high performance" series and features a large electric motor which pulls around 10 to 12A and rugged paddle blades. I was surprised at how much air it moved. This was the largest fan I could find from Spal that would fit in the space I needed it, and it fit perfectly. I used a Bosch style relay to trigger the fan whenever the compressor clutch engaged.
The result? Really cold air from the vents. First test drive I was very impressed. Forecast shows 103 degrees/ 30% humidity at the time of the test drive, and it was blowing 38 degree air at the vents with the blower on medium and vent on recirculation. After 5 minutes of idling, it was still blowing a frigid 42 to 43 degrees. So far, I am impressed. Time will tell if this system meets my needs
Now for pictures.
Brand new Denso Evap, TXV, and drier.
American Condensers drop in parallel flow
Lines cleaned up and wrapped with insulation
Condenser in
Pusher fan in and wired
Foam underneath the condenser to fill the gap. This keeps air from bypassing the condenser and makes sure that any air that is pulled through the radiator is pulled through the condenser first.
And the vent temps while driving (clutch cycles off at about 38 to 39 degrees at the vent, and back on around 42 degrees at the vent)
And vent temp after almost 5 minutes of idling
Will keep the thread updated as I get more use out of it.
The good stuff.
First thing I wanted to do was upgrade the condenser to an aftermarket parallel flow unit. The stock condenser is serpentine which is a decent design, but not quite as efficient at releasing heat as a parallel flow of the same size. The parallel flow has smaller channels for the vapor refrigerant to travel through allowing it to release more heat faster. American Condensers is the only company that makes a drop in parallel flow condenser for our cars.
My car didn't have a pusher fan stock, and the line configuration was such that the suction line in front of the condenser was smack in the middle of the condenser. If I wanted to use an electric pusher fan, I would have to swap the line to the model that has the right bends to allow a pusher fan to fit. Unfortunately, almost all the lines are different, so it wasn't a matter of swapping just the one in front of the condenser. I had to change the hardlines along the firewall and all the lines in front of the condenser. The only lines that could remain unchanged were the flex lines off the compressor. So I got lines from a donor car and flushed them out to get any old oil or debris out.
To take it a step further, I wrapped all the suction lines with insulation foam. This will keep any ambient and engine bay heat out of the suction lines which would make more work for the condenser.
Next thing on the list was the evaporator core. The pre 89 Supras use a serpentine evaporator, whereas the 89+ Supras use a plate/fin evaporator. Just like the condensers, the plate/fin is a more efficient style of evaporator and removes heat from the air more efficiently. I got a donor unit from another Supra, but it was covered in oil and had a leak. I bought a brand new Denso evaporator and thermal expansion valve to replace it. I had to use the plastic evaporator box from the 89+ to fit the plate/fin evaporator in place. The pre 89 evaporator box will not work with an 89+ evaporator. Along with the new evap and TXV, I got a new Denso reciever dryer, which should be replaced any time the system is opened up.
Finally, I bought a 10" Spal pusher fan. I have used Spal fans in the past and have been very happy with them. Spal makes fans for OEM applications and the aftermarket units are on par with OEM quality. This fan is from the "high performance" series and features a large electric motor which pulls around 10 to 12A and rugged paddle blades. I was surprised at how much air it moved. This was the largest fan I could find from Spal that would fit in the space I needed it, and it fit perfectly. I used a Bosch style relay to trigger the fan whenever the compressor clutch engaged.
The result? Really cold air from the vents. First test drive I was very impressed. Forecast shows 103 degrees/ 30% humidity at the time of the test drive, and it was blowing 38 degree air at the vents with the blower on medium and vent on recirculation. After 5 minutes of idling, it was still blowing a frigid 42 to 43 degrees. So far, I am impressed. Time will tell if this system meets my needs
Now for pictures.
Brand new Denso Evap, TXV, and drier.
American Condensers drop in parallel flow
Lines cleaned up and wrapped with insulation
Condenser in
Pusher fan in and wired
Foam underneath the condenser to fill the gap. This keeps air from bypassing the condenser and makes sure that any air that is pulled through the radiator is pulled through the condenser first.
And the vent temps while driving (clutch cycles off at about 38 to 39 degrees at the vent, and back on around 42 degrees at the vent)
And vent temp after almost 5 minutes of idling
Will keep the thread updated as I get more use out of it.
The good stuff.
