A turbocharger boost control valve allows pressure to bled away from the wastegate, which allows the ECU to control the boost pressure of a turbocharged engine. The valve uses a duty cycle controlled shuttle to ensure that the standard wastegate pressure is still used to control boost, with the valve bleeding off the rest to achieve the desired boost level.
The turbocharger boost control valve is compatible with all MoTeC ECUs, connecting to an auxiliary output on the ECU, which uses PWM to control the amount of pressure bleed off.