Optimization for one gasoline engine exhaust system based on BOOST

One-dimension unstable simulation was performed on a gasoline engine using AVL BOOST software. The results show that the 4-1 connection of the exhaust manifold caused the strongly disturbance between the nearby working cylinders, and the Volumetric efficiency was affected. Meanwhile, as the increasing maturity of the three way catalyst converter, the distance between the catalyst converter and the exhaust valve can be increased. Therefore, the connection of the exhaust system was changed from 4-1 to 4-2-1 and verified by the testing result. The redesigned exhaust system reduced disturbance between the nearby working cylinders, decreased the back pressure, and optimized the exhaust system.