how mercedes benz achieve variable oil pressure on 5.5l v8 biturbo
most oil pump use constant flow oil pump with a spring loaded oil pressure regulator. the oil pump is always connected to the crank. so that the oil pressure varies based on engine rpm.
in mercedes benz 5.5l v8 biturbo engine.
the oil pump assembly consists of 2 parts. 1 is the main oil pump to the engine. the other is a suction pump from the oil returns lines of turbo.
as you can see on the video. the geometry is variable and ecu has the control on the oil pump. depending on the requirements. the pump can pump more oil or less at that specific rpm. it can be used to control the flow and pressure.