HELIRLC

Question on a/c compressor.
is anyone using the GM a/c compressor???
I’m using the Mazda a/c power for the clutch engagement.

question is where how do I handle the back wires on the GM to make the proportional valve work.
thanks.
yes I tried to search the web. And Google with fails.

Stubbs

iTrader: (1)

That's the Electronic Variable Displacement Control Valve. It's driven by variable current to vary the displacement of the AC compressor based on demand. Usually they are controlled by a body control module or ac control module. You'll have a difficult time getting it to work as designed without integrating the correct control modules or using a standalone controller.

The variable compressors are designed to deliver a more constant volume at variable engine speeds(mainly to reduce engine load to maximize fuel economy.) The control scheme will vary by manufacturer. Some have the uncontrolled(off) valve position provide max displacement, while others have it provide minimum displacement.
Running it uncontrolled with max displacement all the time causes an excessively high volume to be pumped at engine speeds higher than idle. This can cause higher parasitic power loss as well as accelerated compressor wear/early failure.
Running it uncontrolled with min displacement will not provide enough compression to for the AC system to function.

Another potential issue with that compressor is that it's designed for R-1234yf refrigerant. R-1234yf is stupid expensive and a huge pain to fill properly. While you can use R-134a in a system designed for R-1234yf it's generally not recommended, although I suspect most of the recommendations against it are targeted at people retrofitting newer cars already using R-1234yf to R-134a.

A potential alternative would be to use a 2010-2015 V6 Camaro compressor.
It's a fixed displacement R-134a compressor so you will only need to control the AC clutch.
I'm not super familiar with the differences between the LFX and LGX blocks, but from what I understand they are identical externally with all the same mounting points
The mounting points on the compressor are different from the 2016+ Camaro, but you can find the adapter bracket (gm part number: 92068682) in a junkyard or Ebay fairly cheaply. Alternatively Keisler Automation makes a bracket to fit as well. LFX Adapter bracket

The other alternative, if you have any experience with microcontrollers, would to would be to have an Arduino control the EVDCV. You'd need to add a 3 wire low side pressure sensor(not a pressure switch) on the suction side to provide feedback to the Arduino and write some code. Powering the EVDCV directly from the Arduino will exceed the Arduino's current limit so you'll need use a MOSFET to drive the valve. There's loads of cheap off the shelf breakout boards that could handle it, something like a IRF520 driver board should work if it's under 4 amps.
Here's an example with some code you can base it on that will likely work with minor tweaks. Arduino PWM Driver Example It's focused on driving a DC motor, but it should be interchangeable. In the linked diagram you'll replace the 9v battery with switched 12v, the potentiometer with your pressure sensor, and the DC motor with the EVDCV. You'll also need to run Switched 12v to the Vin and a chassis ground to Gnd on the Arduino board. I'd use an Arduino Nano or Nano Every instead of an Uno to keep the form factor smaller.
You'll likely need to adjust the pot values in the code to match the pressure sensor. The output value may need to be inverted depending on the control scheme used by the compressor.
This is all relatively easy if you've got some familiarity with microcontrollers and electronics, but can be pretty daunting of you don't.

HELIRLC

Thanks. I had an idea that a temp sensor in front of the a/c inside coils to a voltage adjustable reducer type to vary the power to the back valve on the compressor may help modulate the actual flow output. That make sense too??

Stubbs

iTrader: (1)

You could probably use a thermistor in the evaporator to control a current limiting power supply, but I don't know of anything off the shelf you could adapt other than expensive industrial controllers. However, it's not going to be very accurate and wil take a lot of fiddling to get it tuned to your AC system. It'll likely be cheaper, easier, and a whole lot less frustrating to use the fixed displacement compressor off the LFX.

HELIRLC

I had the GM dealer run my donor vin. It’s early 2016. They still used r134, end of that year they switched to the newer one you mentioned. I can source a Johnson temp control to do my idea. So should be able to make it do what i need anyways the older fixed for me is out since Andrew doesn’t want to sell me parts and prices. He wants to sell whole swap kits and he lives 30 minutes from me. I’ve asked him multiple times for things for the LGX swap and says it won’t fit. But now he is doing some prototype installs for some people. I started mine in Feb. and Andrew wouldn’t talk or give me any direction to make it work. Been totally on my own.