12:05 Garage- ’70 Duster build
Spent some time finishing up most of the AC. I didn't care for the shiny black paint on the panel I built, so I sanded it down and painted it matte black so it would match the dash better. I also tied the AC control into the Megasquirt. Above I mentioned I may have to use two relays, but I was able to get the control function working by using a single, two pole relay. When AC is on, the idle bumps up 50 RPM. I started with 150 bump, but that was way too much. It will cut the compressor off above 70% throttle also. While I had the computer hooked up, I spent some time messing with closed loop idle. I have been running it open loop for a while now and it worked pretty good. I figured with the AC load now on the engine, it would be best to have closed loop manage it. The developers of tuner studio also recently updated their firmware to include timing control in the closed loop function. I got it working pretty good and I think it is due to the added timing control to help the engine maintain speed vs. just using the IAC. I'm sure once it gets cooler outside I will have to make more adjustments, but for now it is good. Here are some pics of the finished AC control/vent panel. I still need to make a small one for the driver side by the door. The light shadow on the second pic makes the panel look wavy and crooked. I assure you it isn't. I also included a pic of the drawing of how I connected the AC to the MS3. The I/Os on the MS3 are all ground signals, hence the need for a relay. The output to drop out the compressor is acting as the ground for the relay. Once I hit 70%, that ground is removed and the relay drops out and the compressor shuts down.
Spent some time finishing up most of the AC. I didn't care for the shiny black paint on the panel I built, so I sanded it down and painted it matte black so it would match the dash better. I also tied the AC control into the Megasquirt. Above I mentioned I may have to use two relays, but I was able to get the control function working by using a single, two pole relay. When AC is on, the idle bumps up 50 RPM. I started with 150 bump, but that was way too much. It will cut the compressor off above 70% throttle also. While I had the computer hooked up, I spent some time messing with closed loop idle. I have been running it open loop for a while now and it worked pretty good. I figured with the AC load now on the engine, it would be best to have closed loop manage it. The developers of tuner studio also recently updated their firmware to include timing control in the closed loop function. I got it working pretty good and I think it is due to the added timing control to help the engine maintain speed vs. just using the IAC. I'm sure once it gets cooler outside I will have to make more adjustments, but for now it is good. Here are some pics of the finished AC control/vent panel. I still need to make a small one for the driver side by the door. The light shadow on the second pic makes the panel look wavy and crooked. I assure you it isn't. I also included a pic of the drawing of how I connected the AC to the MS3. The I/Os on the MS3 are all ground signals, hence the need for a relay. The output to drop out the compressor is acting as the ground for the relay. Once I hit 70%, that ground is removed and the relay drops out and the compressor shuts down.