AOsipower,
When you wire up the system you will do what zstroken said and wire them in series. You always want to power the solenoid off a relay, so you wire the WOT Switch, the (normally open) Hobbs Switch, and a toggle switch all in series (in line) on the "trigger" wire to the relay. Pull 12V power from somewhere, run that wire to the toggle, then to the WOT Switch on the pedal, then to the Hobbs in the intake horn, and then finally to the relay. When the switches are "on" (toggle flipped on, pedal @ WOT, and boost above the set point to close the switch) the relay will fire to trigger the nitrous. Setup that way it's really foolproof with a manual and you will have no worries of spraying too early. Start small... say with a .030 or a .040 jet to give you 30-40 hp and go from there. IMO a progressive controller is a waste of money if you're only going to spray a small shot. Also, if you spray water in the intake spray your nitrous pre-CAC.