The controller allows you to increase voltage based on boost. The updated Fuel Pump Booster is an easy way to maintain the proper fuel pressure on your car after adding a power adder such as a turbo or supercharger. The Booster ensures that the engine receives the fuel it needs to make up for the increase in air being pumped into the intake manifold. It will increase the voltage to the factory fuel pump in proportion to manifold boost pressure in order to maintain the proper fuel delivery. The amount of increase is adjustable from a range of an additional 1.5 &ndash22 volts and up to 30 psi which can all be set and adjusted from your PC with MSD&rsquos easy to use Windows based software. The MSD Booster will wire to the factory fuel pump relay or with a secondary booster pump. Features The Booster allows you to make your boost adjustments through a PC for improved control and accuracy. Voltage output is adjustable up to 22 volts at 15 psi of boost For use with stock electric fuel pumps or secondary booster pumps NOTE The Fuel Pump Booster cannot be used on fuel systems without a return line (pulse-modulated pumps). This part is legal for use on Uncontrolled (Non-Emissions Controlled) Vehicles or Racing Vehicles. The following vehicles are considered Uncontrolled (Non-Emissions Controlled) Vehicles 1965 and older U.S. manufactured California Certified vehicles 1967 and older U.S. manufactured Federally Certified vehicles 1967 and older Foreign manufactured vehicle Racing Vehicles are vehicles that are used exclusively for racing or other forms of competition that are not registered and that may never be used on the street.