Racelogic and Aquamist?
 

Hey guys,

I'm considering buying both an aquamist water injection setup and the racelogic traction control, but I'm a little worried about their interaction. The traction control works by cutting fuel.

The fuel injectors work off of a common +12V wire, and individual grounds. I assume that the ECU connects the injector ground wires to an actual ground when it wants the injectors open and disconnects the ground wires from actual ground when it wants the injectors closed (feel free to correct me if you think differently :)).

I believe the traction control sits between the injector and the ECU on the ground side. Something like this:

+12V -> Injector -> ground wire -> TC -> wire -> ECU

I have an email out to the Racelogic guys, but I'm assuming the traction control works by simply leaving the ground disconnected when it wants to cut fuel. That way when the ECU tries to connect the ground from the injector to actual ground, nothing happens, the injector doesn't open, and fuel is cut.

Now my question :). Will the aquamist setup work in a system like this? I see that in the HFS3/6 systems, they somehow watch injector duty cycle. I'm not sure what they tap into for that information. However, I'm assuming they will see when the TC cuts fuel and when it does not. That is, if the TC is cutting fuel on 3 of 6 rotor chambers, you will see 50% of whatever duty cycle you would normally see. For the sake of argument, let's assume a linear water injection map. In that case, the water injecttion setup will only inject 50% of the water volume that would normally be injected, correct?

This seems like a problem. Since the water is injected into the intake rather than into the rotor housings directly, that means that the rotor cycles that are still getting fuel are now getting 50% of the water that they would normally get.

Is there any way around this that people have thought up, or are any of my assumptions wrong? Like I said, I've got an email out to Racelogic for help, and I'll send one to Aquamist too. I just wanted to post here to see if anyone has this working.

Thanks for any help!

- Andy

I am going to assume the aquamist is looking for an earth trigger from the ecu- the injector output.

So if it takes the injector earth (tee'd or in parrallel)signal from the ecu before the T/C unit it won't know any different and will see the full duty cycle.

(ECU earth) T (racelogic)-(injector)- (positive power)
..................I
................(Aquamist trigger line)

Or positive to neg as you wrote it

+12V ->wire -> Injector -> wire-> T/C -> split wire T -> ECU injector earth
.................................................. .....................-> Aquamist trigger input

Thus you have full WI duty and functional T/C :)

I have Racelogic Traction Control for years and HFS-3 since May 2010 and have no problems.

Ken

If you're on e85, you don't need the AI anyway so a 50% AI dose on a cycle that still fires isn't going to be much risk, you will just see more heat transfer to block and higher EGT for that cycle than you would with full AI. If you are past the limit of pump fuel alone and the TC is activated for more than a fraction of a second (and the aquamist is taking a signal that has been interfered with by the racelogic if it isn't wired correctly) with significantly less AI that could be a problem. You haven't given any detail on how yours was setup.