FYI...they are also coming out with a programmable zex kit. This means you can basically set what size shot you want at a certain rpm. You can set it for a 20 shot at 2K rpms and ramp up to a 100 shot by the time you hit 5K rpms.
They can do this through a controller that monitors your rpms of course and then they pulsate the selenoid that lets the nitrous out. You set up the car for a 100 shot...but then the selenoid only opens for microseconds every few microseconds to let out very small quantities of nitrous to get a smaller shot.
With this controller, supposedly can be used on a standard nitrous setup.