i had nitrous on my Miata; and i did my research beforehand... it was a fully automatic wet system, NX 50-shot, that sprayed if and only if:

(1) the system was 'armed' (main switch turned on)
(2) your foot was on the floor (full throttle)
(3) you were above 3K rpm (selectable via rpm switch box)
(4) the fuel pressure did not drop below a predetermined amount (fuel pressure switch)

i know i have a wiring diagram somewhere if you want me to look. i can also go into more detail if you're interested.

hence my user name, and the leftover license plate that i still have on my crossfire.