Does anyone know how the internals of the Nitrous Management Unit work? I'm just curious, I've recently installed a 55 horse wet shot, and would like to know exactly how the unit varies fuel delivery according to bottle pressure.

There's obviously 2 solenoids, one for fuel and one for nitrous. And there's gotta be an electronic board that learns the TPS WOT voltage for triggering the solenoids. But how does it vary fuel delivery per N2O pressure? Is there a nitrous pressure transducer and a PWM fuel solenoid, or is it a mechanical expansion valve, or what? I'm stumped...

 

well if its like the old dry kits, it doesnt. the circuit board in my old kit took a **** so i said screw it and took the solenoid out and mounted a switch on my throttle body to trigger it. any way while i was taking it apart i thought also, how does this work? all they had was a big machined brass block with 4 ports on it, 2 ports on one side were connected through a chamber in the block. these were the vaccum line ports in/out for the fpr. then there were 2 more ports, one in from the nitrous solenoids output and one out to the spray nozzle. these were also connected through a chamber inside the brass block. then between the 2 chambers it had been drilled and threaded and a threaded allen block off fitting was threaded in to keep the chambers sealed from each other. so basically the nitrous passed straight through the block, and the vaccum passed straight through the block only being effected by the nitrous jet that goes inside of one of the fittings on the outside of the box there was absolutely no kind of sensor of any type to adjust anything for bottle pressure. all it amounted to doing was putting a nitrous jet inline from you pfr to your intake manifold on the vaccum line.

 

Hmm, interesting... So what you're saying is the dry kit NMU just uses a vacuum orifice to control the regulator. I wonder if they use something similar on the wet kits...?