The turbocharger has two turbine wheels mounted on one shaft, which are located in housings separated from each other. The wheels are driven by exhaust gases. They increase the rotation frequency of the supercharger shaft to 120,000 revolutions per minute. Since the rotor driven by the exhaust gases and the rotor for the intake of fresh air are located on the same shaft, atmospheric air is forced into the combustion chambers of the cylinders with the same frequency. The turbocharger is lubricated with engine oil through the corresponding oil line. In cars with a gasoline engine, the turbocharger is cooled by a coolant.
Due to the good filling factor, a power increase of up to 100 percent can be achieved in existing engines. The extent of this increase depends, among other things, on the boost pressure, which in a passenger car is between 0.4 and 0.8 bar (the tire pressure is about 1.8 bar). The boost air pressure is continuously monitored and regulated by the engine control unit via the boost pressure sensor. This prevents the boost air pressure from exceeding the maximum permissible value.
Along with the increase in power characteristics, the use of a turbocharger also increases the torque, which has a positive effect on the elasticity of the engine. This is only possible if the supercharger shaft rotates at a sufficient number of revolutions and thus ensures the proper filling of the cylinders. For this reason, cars with a gasoline engine are equipped with a relatively small turbocharger, which already operates at low engine speeds and increases its torque.
Charge air cooling radiator (intercooler) reduces the temperature of the air compressed by the supercharger. This increases engine power because the cooled air has a higher oxygen content due to its higher density.
The turbocharger in cars with a diesel engine of power is equipped with a turbine with variable blade geometry. The geometry of the turbine wheel blades is smoothly adjusted by the engine microprocessor through electromagnetic and membrane valves. Thus, at all engine speeds, optimal boost air pressure is ensured, which increases torque, especially at low engine speeds.
In contrast to the internal combustion engine, in a diesel power plant, thanks to supercharging, there is no need to reduce compression, which allows the injected fuel to be fully utilized even in the lower engine speed range.
The turbocharger is an extremely precisely manufactured unit. As a rule, in case of failure, the turbocharger is replaced completely.