Chris: The wet system that I helped install had a micro-switch actuator that completed the circuit to supply power to the solenoids. This actuator had to be depressed to complete the circuit and we simply mounted on the throttle bracket and when the throttle body's foot hit the acutator, it completed the circuit. We had to hook up an AutoTap to make sure we placed the actuator properly so that it was depressed only at 85+% throttle angle, or WOT. Since you don't want to actuate at anything less than WOT, I wouldn't recommend actuating at secondary cut-in because the secondaries can be opened above 3,500 RPMs without the car being at WOT. WOT is importatant because you need full fuel flow to compensate for the nitrous. Example: I wire the thing to trigger off the opening of the secondaries and I easy into 1st gear, say at 50% throttle. Regardless of throttle angle, at around 3,500 RPMs, the secondaries will open and I will have 100% nitrous with only about 50-65% fuel ... I will run lean and detonate and possibly fry a piston or valve or both. However, I think that you are talking about wiring a second microswitch "inline" with the first. This way, the throttle angle of 85+% is sensed first, completing the first circuit and then passes the power to the second circuit where it waits to be completed by the secondaries opening up. Once the secondaries open and the circuit is completed, power is now provided to the nitrous and fuel solenoids. Is this correct? If so, it may be overkill because if you have the first microswitch set to open at WOT, then chances are that your secondaries are already open. There are circumstances where this will not be true, but for the most part, at WOT, the secondaries will be open. Please correct me if I am wrong.
