A fuel charging system which injects nitrous oxide into the engine of a high performance vehicle to provide an instant burst of power to the vehicle. A nitrous oxide supply line feeds nitrous oxide under pressure from a supply container thereof into the vehicle engine through a spray bar. A normally closed solenoid valve controls the flow of nitrous oxide into the vehicle engine through the supply line. The supply line also is connected to a vent tube having a normally open solenoid valve controlling the flow of nitrous oxide thereto. The vent valve communicates with a one-way low pressure actuated check valve and vents any nitrous oxide leaking past the closed solenoid control valve into the atmosphere to prevent the harmful buildup of nitrous oxide in the engine. A pair of pressure actuated electrical switches are connected to and actuated by the pressure of the oil and fuel sources of the vehicle to prevent the actuation of the nitrous oxide control valve if a sufficient supply of fuel is not available to mix with the nitrous oxide and if the engine RPM is not sufficient for receiving the additional burst of power. The check valve reduces momentary back pressure in the nitrous oxide flow line which heretofore occurred at the time when increased power is needed most in a race. Also the vented leaking nitrous oxide is visable to the vehicle operator enabling appropriate action to be taken to prevent damage to the vehicle.

An injection nozzle utilizing nitrous oxide to aid in the introduction and atomization of fuel into a combustion chamber. The present invention comprises a Y shaped nozzle having a pair of input ports and a single output port. One input port is utilized to introduce nitrous oxide into a hollow sleeve of the nozzle and ultimately exiting at the output port. The second input port introduces fuel to the nozzle. A fuel line coupled to the second input port extends the length of the hollow nozzle, terminating at the output port extends the length of the hollow nozzle, terminating at the output port. The nitrous oxide is introduced at high pressure, approximately 500-1000 PSI. The fuel is introduced at approximately 3-12 PSI. As the nitrous oxide exits past the end of the fuel line, it creates a vacuum which aids in drawing the fuel from the line. In addition, the high pressure and vaporization of the nitrous oxide atomizes the fuel so that it is fully dispersed and once within the combustion chamber may be more efficiently burned.

An injection nozzle utilizing nitrous oxide to aid in the introduction and atomization of fuel into a combustion chamber. The present invention comprises a Y shaped nozzle having a pair of input ports and a single output port. One input port is utilized to introduce nitrous oxide into a hollow sleeve of the nozzle and ultimately exiting at the output port. The second input port introduces fuel to the nozzle. A fuel line coupled to the second input port extends the length of the hollow nozzle, terminating at the output port extends the length of the hollow nozzle, terminating at the output port. The nitrous oxide is introduced at high pressure, approximately 500-1000 PSI. The fuel is introduced at approximately 3-12 PSI. As the nitrous oxide exits past the end of the fuel line, it creates a vacuum which aids in drawing the fuel from the line. In addition, the high pressure and vaporization of the nitrous oxide atomizes the fuel so that it is fully dispersed and once within the combustion chamber may be more efficiently burned.

A pulse width modulated controller for N.sub.2 O and enrichment fuel delivery includes a system control logic section which processes signals from sensors for throttle position, engine speed and a number of other user-selectable parameters and a driver section controls electrically operated injectors or solenoid valves. The driver section allows the injectors to open only when all of the parameters sensed in the control section are met. Moreover, the driver section activates injectors according to a pulse generated by a pulse width modulation section which determines how long the injectors will remain activated. The pulse width modulation section receives signals based on the present throttle position and engine speed and adjusts these values according to values for N.sub.2 O and enrichment fuel based on engine speed and throttle position set by the user in a tuning section and thereby continuously provides the driver section with a pulse having a width proportional to the proper amount of N.sub.2 O and enrichment fuel which should be delivered at any given time. In addition, the tuning section is also user-settable to a maximum ignition timing adjustment and provides a signal proportional to ignition timing retard to an ignition control section for automatically adjusting ignition timing according to the amount of N.sub.2 O and enrichment fuel being delivered at any given moment.

A circuit for decreasing the engine speed of a drag racer for a selected interval during a race has a programmable first down counter for setting the time the interval begins, a programmable second down counter for setting the duration of the interval and a clock connected to both counters.