Turbochargers operating principles
The principle of turbocharger is simple. It consists of two rotors placed on a common shaft. One of them is located in the exhaust system and is driven by exhaust gas extracting energy from the engine.
The second rotor is located in the inlet manifold. Thanks to a specially contoured shoulders, and under the influence of rotation of the shaft he pumped air into the engine at a pressure higher than atmospheric pressure. Then the engine is running efficiently.
It’s because of the produced power which depends on the dose of fuel that was burned at a given time. You must provide enough oxygen to burning to be effective.
14 kg of air is required to burn 1 kg of fuel. More pumped air can burn more fuel respectively with the same speed and the same engine. The mixture burns more, so fumes are less toxic.