Holley EFI 557-200 3 Port Solenoid Valve

Our 3 port boost control solenoid is designed for optimal performance when using the boost control function of Holley EFI. Some setups require two solenoids and some require one. The solenoid is driven by a Pulse Width Modulated (PWM) output of the ECU. It is advised not to use the PWM+ outputs on an HP ECU, but rather use the PWM- Outputs. If you have a Dominator ECU, either use the PWM- outputs, or use a PWM+ output on the J2B connector.