as per stu... the extra fuel required is supplied by the nitrous kit, it pumps in nitrous AND fuel

very simple. you just T off of the std fuel feed hose and this runs to the nitrous pulsoid, which when activated will open and allow the extra fuel required to flow thru into the crossfire injector (via a jet which is just a "thing" with a hole in it, depending on what size hole you use depends on how much fuel can flow)

but getting a std cossie up to 500bhp with JUST nitrous... erm... very doubtfull