Hi i have been brainstorming about doing a intercooler sprayer for the past couple of hours and i know pretty much where i am going with it. but i need a way to power the pump only under WOT is there a way to wire a switch to a signal on the pedal input or a switch that would trigger only when WOT

 

I'm not 100% on this, but since the throttle body is electronic, my guess is the throttle pedal is nothing more than a large variable resistor that takes the standard 0-5v range from the ecu and inputs a voltage range back to the ecu depending on throttle position, which then translates to throttle plate position that the ecu sends to the throttle body. You might be able to do it with a voltage comparator circuit of some type that reads the throttle output and only turns on at a certain voltage range? Hopefully it doesn't alter the output signal running to the ecu either...

Wouldn't it be easier to go off injector duty cycle at that point? Have the sprayer turn on once IDC hits a certain percentage.

 

Instead of trying to tie into CAN or anything like that, instead just pick up a temperature switch, or a pressure switch, or a few temperature sensors and control it with either 'dumb' logic, or an arduino.

In a nutshell, dont worry about wot, worry about the resultant conditions in which you would need the sprayer. High delta T, high intake pressure, etc.

For a simple setup, just pick up a 10psi pressure switch, Normally Open, and wire that to your sprayer pump and put the switch somewhere in your intake path. Should be able to plumb it in sort of like a boost gauge.

You coupd do the same think with a temperature switch, but youd have to pick some temperature and stick to it.

Or you could use an ambient temperature sensor, and one in the intake path, and use a logic controller (arduino or the likes) to flip a relay to turn on the pump whenever iat delT's went too high.


Or get a vipec and do the same thing (would be built in. Just need the aux harness)

But with any of the solutions i would put in a provision for a level sensor in your water tank to open the relay should the level drop too low (prevent the pump from running dry)

Just my .02