Despite the tightening of environmental regulations, piston engines are used in virtually all sectors of the economy in Russia and the world. It is known that improvements in the design of intake and exhaust systems, including turbocharger, serve as an effective way to improve the performance and environmental performance of engines. In the framework of these work, comparative studies of two designs of turbocharger system of diesel engine 8ChN 21/21 (rated power of 1000 kW at a crankshaft rotation frequency of 1500 min-1) were carried out. In the first version the engine was equipped with one turbocharger TK18B, in the second - with two turbochargers TKR180 of Russian production. The bench tests were carried out according to the diesel locomotive characteristics (eight positions and on the power plant mode of 1000 kW - the ninth position). As a result, experimental data on the main technical, economic and environmental performance of the diesel engine under consideration with different turbochargers were obtained. It is shown that the use of two turbochargers in the supercharger system of 8ChN 21/21 diesel engine instead of one has a number of positive effects: 1) reduction of specific fuel consumption by 1.8...2.2 %; 2) increase of mass air consumption by 5.5 % on average; 3) reduction of nitrogen oxides, carbon monoxide and hydrocarbons emissions concentration in exhaust gases by 37, 35 and 20 % on average respectively. In addition, further directions for improving the technical, economic and environmental performance of the diesel engine are formulated.