How the turbocharger works

Turbocharger or turbo of a car

There are many components that allow the correct functioning of our car. Each one of them plays a fundamental role, which they would not fulfill without the particular characteristics that make them indispensable. Here we are going to present you the turbocharger . An element of which you have surely heard, but whose operation is not so well known.

A turbocharger, also called turbo, is a system that introduces air under pressure in the cylinders . By having more oxygen, you can burn more fuel and therefore get more torque. With air at ambient pressure (1 atmosphere), this would be achieved with larger combustion chambers, or what is the same, with more displacement.

The operation of the turbo is based on the use of exhaust gases . As the smoke of the cylinders comes out with some speed, it is used to move the turbo and that it accelerates the ambient air and puts it in the engine. Let's see what the parts of the turbo are and what role each has to understand how it works.

Basic parts of the turbocharger


This is the key element to take advantage of the movement of the exhaust gases. The exhaust gases spin the turbine so that the turbo accelerates the air entering the cylinders. The turbine can be of two types: of fixed vanes or variable vanes . The latter can tilt more or less their blades, to achieve various effects such as improving filling at low revs or increase the flow at high revolutions.

Coaxial axis span>

The turbine that turns is connected to the compressor by means of a coaxial axis that transmits its movement. It is a piece that must be very well lubricated because otherwise it would wear out very soon due to the high speeds at which the turbo works. Therefore, it is important to choose the oil type of our engine well. If it is not fluid enough, it will not cover all the parts that need lubrication.


The movement of the turbine is transmitted to the compressor wheel through the shaft. The rotation of this wheel pushes the air like a fan into the compressor. Once there the air will accelerate because the duct is narrowing little by little. That's why the compressor has that peculiar snail shape. Once accelerated, the air passes to the intake manifold, where it is led to the cylinders.

Turbocharger or turbo operation

Discharge Valve

One of the most important parts of this turbocharging system is undoubtedly , your valve waste-gate or discharge valve . This valve prevents the excessive pressure of the gases from having an impact, damaging the engine severely. For this purpose, it regulates the amount of gases that escape from the turbo exhaust to the vehicle's exhaust by opening it.

Relief Valve

Secondly, the so-called valve dump valve , relief valve or valve blow off , which is the responsible for preventing the pressure caused by the strong inertia of the turbo saturating the ducts, which would result in a strong deceleration of the turbine.You can do it by air, by water or by a gas. In this way, as it allows us to put more oxygen in the same space, the performance of the engine can be higher.

Some turbos also need their own cooling system given the enormous temperatures they reach (especially gasoline). When it is not enough to circulate oil through it, it uses a cooling system by air or water.

The use of turbo in modern cars

The use of the turbo has increased over the years. Especially for the called downsizing effect, which consists in decreasing the size of the engines to change from putting air to pressure. This will reduce consumption slightly , since reducing the size of the cylinders will reduce friction. The friction of a 3.0-liter engine is not the same as the one of a 1.8-liter engine . In addition, the weight of the engine components is also lower, reinforcing the effect of fuel savings.

As a counterpoint, the engineers have had to deal with problems such as excess heat in the chambers of combustion . If explosions are caused by a 2.0-liter engine in a 1.0-liter engine, the heat has to be distributed in less metal. This can again cause problems such as self-detonation or the pursued generation of polluting gases such as NOx.

If you want to know more about the turbocharger of a car, do not miss the article about its advantages and disadvantages. Although many brands have opted to use it on all its engines, there are those who still resist as Mazda. A decision that has brought very interesting technologies to compensate for the virtues of the turbo like Skyactiv-X engines. You may be interested