Pumping loss adjusting system

The invention provides a pumping loss adjusting system, and belongs to the technical field of internal combustion engines. The pumping loss adjusting system comprises an engine air feeding tube, a supercharger, an engine, an engine exhaust tube, a turbine, a connecting tube, an adjusting cavity, a rotating shaft, a rotating plate, a control cavity, an internal tube, a spring, a rotating body and a stress plate, wherein the adjusting cavity is coaxially connected with the control cavity through the rotating shaft; the stress plate is connected with a left wall surface of a fixed body through the spring; one end of a second connecting tube is connected with an internal cavity body of the control cavity; and the other end of the second connecting tube is connected with the engine exhaust tube between the turbine and a catalyzing pack. In the pumping loss adjusting system, when the engine runs under the working condition of high speed, the front exhaust volume of the turbine is large, pumping loss is low, and oil consumption is low; and when the engine runs under the working condition of low speed, the front exhaust volume of the turbine is small, pulse energy can be used sufficiently, and the oil consumption is low. The pumping loss adjusting system is reasonable in design and simple in structure, and is suitable for the optimization design of an exhaust system of a turbocharged engine.