Compressor Air Intake Supercharger Description and Operation: Operation

The supercharger is designed to increase the air pressure and density in the intake manifold. When this air is mixed with the correct amount of fuel the result is more power from the engine. This excess air creates a boost pressure in the intake manifold with a maximum engine boost of 66.9 kPa (9.7 psi). Because the supercharger is a positive displacement pump and is directly driven from the engine drive belt system, boost pressure is available at all driving conditions.

The bypass actuator is a vacuum operated valve that is connected to the vacuum signal between the throttle and the supercharger inlet. Vacuum to the actuator pulls the bypass valve open during idle and light load conditions to decrease boost.

The ECM controls boost pressure by limiting throttle control via logic in the software. At idle, engine vacuum is applied to the upper side of the bypass valve actuator, counteracting spring tension to hold the bypass valve open. When the engine load is increased, the engine vacuum is decreased, causing the spring in the bypass valve actuator to overcome the applied vacuum, closing the bypass valve and allowing the boost pressure to increase. The bypass valve starts to close when the vacuum is 33.9 kPa (10 in Hg) and is fully closed at 11.9 kPa (3.5 in Hg). When reduced boost pressure is desired, the ECM enables boost protection by commanding the throttle, causing the supercharger inlet air pressure to drop relative to barometric pressure, allowing the bypass valve actuator to open the bypass valve, redirecting the charged air.