The Influence of Exhaust Backpressure Upon the Turbocharger’s Boost Pressure

Abstract

The authors present their studies that were conducted in order to analyze the behavior of the turbocharger of a compression ignition engine while the exhaust was obstructed at different levels to simulate the influence of different levels of exhaust backpressure upon the charging device. The goal was to measure in what way and to what extent is the behavior of the turbocharger influenced by the backpressure caused by a flap, introduced in the exhaust line of the analyzed engine. Tests were carried out on a four cylinder 1.9 dm³ turbocharged Diesel engine fitted to an active dyno. A special flap in the exhaust line, operated by PUMA Open was used to simulate different backpressure values from 0 up to 570 mbar additional pressure. During the test, at each engine speed power, torque, fuel consumption, intake pressure, room pressure, intake pressure and temperature before and after turbocharger was measured and stored. The results of the investigations show a clear dependence of the exhaust backpressure related to turbocharger performances. Exhaust lines can be tuned for certain engine speed domains which are given by the internal combustion engine’s destination.