Actually I'm running 75.
Couldn't feel the 55 shot at all, just heard the spray and watched the RPM's rise.
I was hoping for a bit more of a kick.
When I am going to run nitrous, I open up the bottle manually and it should fill & pressurize the line from the bottle to the NMU.
So when the solenoid clicks on, it should spray right away.
So I wouldn't think there would be any noticeable lag.
Maybe my nozzle is too far back (12 inches from TB)?
What plugs (make and model) are people running with their nitrous?