Abstract: A nitrous oxide and fuel control valve has simultaneous flow control of nitrous oxide from a first fluid-delivery aperture (8) and flow control of fuel from a second fluid-delivery aperture (10) into a mixing nozzle (38) of an intake manifold of an engine by simultaneous actuation of an activation T-bar (18) with an actuation piston (26) that is actuated with gas pressure from an actuation-pressure source (43) with an actuation on/off solenoid valve (44). It can be structured for low-weight, short-term needs for racing and other sports uses or for heavier long-term needs of engines.