Turbocharger is actually a kind of air compressor, which increases the air intake by compressing air. It uses the inertia impulse of the exhaust gas discharged by the engine to push the turbine in the turbine chamber, and the turbine drives the coaxial impeller, which pressurizes the air sent by the air cleaner pipeline and sends it to the cylinder. When the engine speed increases, the exhaust speed and the wheel speed also increase synchronously, and the impeller compresses more air into the cylinder. With the increase of air pressure and density, more fuel can be burned, and accordingly, the output power of the engine can be increased by increasing the fuel quantity.
The biggest advantage of turbocharger is that it can greatly improve the power and torque of the engine without increasing the engine displacement. Generally speaking, the engine power and torque with turbocharger will increase by 20%-30%. The disadvantage of turbocharger is lag, that is, due to the inertia of impeller, it reacts slowly to the sudden change of throttle, which makes the engine delay to increase or decrease the output power, and it will feel a little lag for a car that wants to suddenly accelerate or overtake.