Abstract: A sound control module is configured to determine N magnitudes for outputting a predetermined engine sound at N predetermined harmonics of a base frequency, respectively, where N is an integer greater than one. An adjustment module is configured to determine N magnitude adjustments for the N predetermined harmonics, respectively, based on a position of a compression ratio (CR) actuator configured to vary a CR of an engine. The sound control module is further configured to determine N adjusted magnitudes for the N predetermined harmonics based on: the N magnitudes for the N predetermined harmonics, respectively; and the N magnitude adjustments for the N predetermined harmonics, respectively. An audio driver module is configured to apply power to at least one speaker of the vehicle and output the predetermined engine sound based on the N adjusted magnitudes at N frequencies, respectively, corresponding to the N predetermined harmonics of the base frequency.

Abstract: A fuel pump assembly has a bushing defining a pumping chamber, a plunger, a cam follower piece, and a compliance device for absorbing noise by increasing either or both of a hydraulic and/or a mechanical compliance of the fuel pump assembly. The compliance device may includes a spring washer or a press-fit spring. The pump bushing and/or plunger may include a cavity as the compliance device for increasing dead volume, the cavity being in fluid communication with the pumping chamber via an orifice. A deflectable or movable mechanism is positioned within a cavity for increasing dead volume, and a solenoid varies a diameter of the orifice. The moveable mechanism includes a poppet valve having a switching pressure related to engine speed. A vehicle includes an engine, transmission, fuel rail, and a fuel pump assembly configured with at least one compliance device for absorbing a hydraulic noise component.

Abstract: A fuel pump assembly has a bushing defining a pumping chamber, a plunger, a cam follower piece, and a compliance device for absorbing noise by increasing either or both of a hydraulic and/or a mechanical compliance of the fuel pump assembly. The compliance device may includes a spring washer or a press-fit spring. The pump bushing and/or plunger may include a cavity as the compliance device for increasing dead volume, the cavity being in fluid communication with the pumping chamber via an orifice. A deflectable or movable mechanism is positioned within a cavity for increasing dead volume, and a solenoid varies a diameter of the orifice. The moveable mechanism includes a poppet valve having a switching pressure related to engine speed. A vehicle includes an engine, transmission, fuel rail, and a fuel pump assembly configured with at least one compliance device for absorbing a hydraulic noise component.