MS3 Fan Strategy?
 

Just curious what others are using as a fan strategy.

On My N/A street car with reroute, Big Koyo and all the stock ducting, I have the primary fan come on with A/C, or at 195F and off at 190F. I also have it set to turn the fan off >40 MPH.

Today it hit 90 for the first time this summer and I hit 230 with the air on.. and found out the secondary fan wasn't enabled :facepalm: I configured the second fan to come on 190 with hysteresis of 4.

I just want both fans to start at different times as not to put too much of an initial strain on the electrical system. My car barely makes enough torque at idle to turn the A/C compressor as it is.

Back when I ran two fans I would just offset the on and off points by 2 or 3 degrees to avoid them both coming on at the same time. A/C on of course you would turn on the "A/C" fan. You'll have to experiment at what MPH you can turn off the fans. With really good ducting you could shut them off at 25-30 mph, but with a stock setup and dirty old radiators and A/C coils you might leave them on all the time and still overheat.

With my current v-mount setup with self proclaimed excellent ducting I get by with just the smaller weaker A/C fan and it only comes on when sitting in traffic for more than 5-10 minutes. Moving at more than a walking pace and it doesn't run at all.

I believe Braineack ships his MS3X's with the main fan controlled by the Input/Output menu. He turns it on at 200 degrees, and off at 190. Then the AC fan is controlled by the main Fan control menu item. I think he turns on that one at 210, and off at 200. It is the best way he could come up to make both fans work properly with AC. He asked the MS3 devs to have 2 fans added to the fan control area, but so far no response on that.

correct. since the "Fan Control" menu has an option to "turn on with a/c" I use that for the a/c fan itself, then i set it up to turn on 10° hotter than main fan, which is just on/off.

i put in a request for them to add dual functions in that menu years ago, but alas.