The brains of the system, along with the solenoids, lie within the Nitrous Management Unit. The black button and LED visible on the side of the unit are used during installation to program the unit's WOT-activation switch, basically allowing the NMU to learn the electronic-throttle-control circuit's voltage curve to precisely plot wide-open throttle.
The combination nozzle is clearly marked for insertion of the respective nitrous and fuel jets, which are all clearly numbered. We just stuck in a random pair for photo purposes, but Zex's instructions include a chart setting out the correct jets for the desired horsepower level. PHP used the smallest (75 hp) combination of jets. Notice the threaded area on the body of the nozzle...
...that's used to thread either directly into a metal inlet duct as fitted to PHP's car (part of PHP's V6 cold-air kit) or into an included bulkhead fitting for use with the factory rubber inlet duct. The supplied -3 AN lines are routed to the nozzle from the outlet side of the nitrous-management unit.
The most practical place to mount the nitrous-management unit is somewhere along the driver-side inner fender apron forward of the strut tower. This way, the kit's quartet of braided lines will reach their intended targets. Smart as this setup is, only three wires protrude from the NMU: black goes to chassis ground, red connects to the power wire from whichever of the included interior arming switches you decide to use, and white taps into one of the electronic throttle-control wires using a supplied T-tap. Nice and simple.
The most practical place to mount the nitrous-management unit is somewhere along the driver-side inner fender apron forward of the strut tower. This way, the kit's quartet of braided lines will reach their intended targets. Smart as this setup is, only three wires protrude from the NMU: black goes to chassis ground, red connects to the power wire from whichever of the included interior arming switches you decide to use, and white taps into one of the electronic throttle-control wires using a supplied T-tap. Nice and simple.
PHP chose the simplest arming-switch option-the one that plugs into the 12V power point on the dash. One of its two wires goes to ground, while the power side is passed through the firewall to connect to the aforementioned red wire from the NMU.