A fuel injector adapter for providing nitrous oxide to an internal combustion
engine
is disclosed. The nozzle has a central fuel injector passage that terminates at
a first outlet end. Fuel from a fuel injector may be passed through the central
fuel injector passage. The nozzle also has an inner annular passage arranged circumferentially
around the central fuel injector passage. The inner annular passage terminates
at a second outlet end. The nozzle also has an outer annular passage arranged circumferentially
around the inner annular passage that terminates at a third outlet end. One or
both of the inner and outer annular passages is adapted to pass nitrous oxide through
it. The nozzle is adapted to fit between a fuel injector and an engine without
substantial modification to the engine.