I've edited my post for the time being until I clarify something. Excuse my ignorance, but where exactly is the nozzle plumbed into here? Are you plumbed into the hot side of the intercooler? I cant make out the pic you have posted of the nozzle. If you do, thats fine. In this application it is used moreso for cooling. It will not yield the same gains plumbed like this as a typical nitrous installation. Furthermore, do you have a microswitch under the pedal or do the Zex kits wire in and sense WOT from system sensors? If its wired in to system sensors I would bet the flow is turning on and off continuously because #1, the throttle plate dances around, #2, the throttle plate doesn't open fully.