They're temperature controllers; each one can read one thermocouple, and you can set each one to flip two switches at two seperate temperatures for that thermocouple.
So, lets say I put a temperature probe in my air intake and hook three nitrous solenoids to it. I have one solenoid fire when the pedal hits the switch on the floor, I have one solenoid fire when the air inlet temperature gets to 150 degrees, and I have the last one fire when it gets to 180 degrees.
Or I do the same thing with water/meth nozzles. I have one stage from the start, a second nozzle opens when EGT's get to 1000 degrees, and a third opens when I get to 1100 degrees.
And then, when I'm not running drugs, I use a switch to read other thermocouples instead. Like the thermocouple in my veggie tank, the thermocouple in my injection pump inlet, or the thermocouple in my tranny.
Of the three, I currently have a thermocouple in my tranny line.
Downside to these controllers is that they're 120 volt, so I needed a power inverter.
So I mounted a 160 watt inverter where my fuse box is supposed to go.
(I just JB Welded tie-wraps in such a way to hold the inverter... Didn't have any other ideas...)
Just need some relays and solenoids now...
1990 D-250 Regular Cab: Tweaked injection pump, built transmission, a cataclysmic charlie foxtrot of electronics, the most intense street-ran water injection system in the country, and some more unique stuff.