A/C condensor

[Turbobus]

Well, since you mentioned it-

I have seen some aftermarket kits that are not as well designed as OE Chrysler systems. In a perfect world, you would have a 7-8* condenser approach. That is liquid line temp ( leaving condenser line, heading to the filter-dryer) minus entering ambient air. Here's the thing though, you need a honkin' big fan to simulate the vehicle going down the road. Temps and as a result the pressures vary with airflow.

It would be awesome if there was an EPR valve replacement for 134a. If you could regulate to a constant 33-34 psi in the evap, you could hold a nice temp. Mostly it's the "universal" kits that seem to have the most trouble. Chrysler had well designed piping/hose setups, especially 69 and later. Watch your hose routing, avoid any sharp metal that could wear a hole, exhaust manifolds, etc. Of course, lightly oil the O-rings and any aluminum threads and make sure there's no leaks.

Fan or maybe a propeller! I do remember how well the stock system used to work back in the day and after I rebuilt the hvac box it would blow your hair back. Looking forward to getting it completed, you know, now that winter is approaching

 

[RJRENTON]

Well, since you mentioned it-

I have seen some aftermarket kits that are not as well designed as OE Chrysler systems. In a perfect world, you would have a 7-8* condenser approach. That is liquid line temp ( leaving condenser line, heading to the filter-dryer) minus entering ambient air. Here's the thing though, you need a honkin' big fan to simulate the vehicle going down the road. Temps and as a result the pressures vary with airflow.

It would be awesome if there was an EPR valve replacement for 134a. If you could regulate to a constant 33-34 psi in the evap, you could hold a nice temp. Mostly it's the "universal" kits that seem to have the most trouble. Chrysler had well designed piping/hose setups, especially 69 and later. Watch your hose routing, avoid any sharp metal that could wear a hole, exhaust manifolds, etc. Of course, lightly oil the O-rings and any aluminum threads and make sure there's no leaks.

With regard to your desire for an EPR valve for R134A, most, but not all newer A/C systems, use a pressure switch, which cycles the compressor clutch ON/OFF, to yield the AVERAGE SUCTION PRESSURE of 33#-36#, which nets the same result. (the gas temperature plus the super heat temperature exiting the Evaporator.) The calibrated differential pressure the switch reacts will do the same thing...a switch with a broader dead band range. This will allow the refrigerant temperature, called super heat, to continue to absorb heat. Most new R134A and the newer R123YF systems use a TXV to control the refrigerant entering the Evaporator. BTW...the approach temperature relates to the gas temp and air temp not the liquid refrigerant temperature entering the Evaporator. That is called the subcooling effect....just thought you might like to know.....
BOB RENTON