How does the turbocharger work

To better understand the technique of turbocharging, it is useful to be familiar with the four–stroke piston engine’s principles of operation.

By the diesel or petrol engines, the piston moves down and air or a fuel/air mixture is drawn through the intake valve. In the petrol engine’s carburetor the air is mixed with the fuel.

Since the piston moves up, air or a fuel/air mixture (the cylinder volume) is compressed.

In the petrol engine, the fuel/air mixture is ignited by a sparkling plug, whereas in the diesel engine or direct injection petrol engine fuel is injected under high pressure and the mixture ignites spontaneously. In both case the piston moves down.

The exhaust gas is expelled through the exhaust valve when the piston moves up. In turbocharged engines, the combustion air is already pre-compressed before being drawn directly into the cylinder of the engine during the intake stroke. Due to the higher pressure, more air mass is supplied into the combustion chamber, which is related with the more efficiency during the fuel’s combustion. This increases the engine’s power output, giving the more energy and more speed regarding the conventional petrol or diesel engines (a naturally aspirated engine) and likewise reduces the emission rate. Some diesel engines can be fitted to receipt more air mass with the same fuel volume, which does not increase the power output but results low-emission of exhaust gas.

Princip rada turbokompresora



1. Air suction
2. Exhaust compressed air
3. Intercooler – compressed air cooler
4. The intake valve
5. The exhaust valve
6. Input the exhaust gas in turbine housing
7. Exit (output) the exhaust gas.