Why turbochargers?

They have appeared almost simultaneously with combustion engine – as right from the start engineers were looking for a way to increase the engine’s power. Naturally, it has undergone massive changes over the decades of its development, but basically the idea remains the same.

Although turbochargers can be installed with both petrol and diesel engines, most of the manufacturers currently install them for diesel (much less powerful) vehicles. The reason is simple – petrol engines with turbocharging consumed too much fuel.

However, turbos are found not only in engines of passenger cars. They are present in virtually all modern trucks, heavy machinery as well as other vehicles – whenever there is the need for additional engine power.

It of course resulted in a massive market of reconditioned turbos, spare parts and rebuild, repair kits. Unfortunately, there is a large number of parts out there, which are simply not good enough for the requirements of modern engines. Extreme conditions of work (extreme temperature and rpm) is very demanding on every element of a turbocharger. Which is why it is crucial to select only the highest quality OEM repair kits and parts, recommended by manufacturers.

Turbocharger repair should not be performed by amateurs without professional tools, as further damage might occur if and when a mistake is made.

Principles of operation

Before we delve into more details, let’s go over the basics first. Standard combustion engines rely on natural intake of air into the combustion chamber – in professional terms it is a “naturally aspirated engine”. Such solution has its limitation, as only a certain amount of air (and with it – oxygen required for the fuel to be burnt) can enter the engine.

More air mass = more power

With turbocharging, the air is pre-compressed – meaning more air mass and more oxygen can be supplied to the engine’s combustion chamber. The same amount of air is supplied, but thanks to compression, more air mass can enter the engine, which results in more fuel being burnt and, of course, more engine power.

In short: a turbocharger gives the engine more power.

Design
There are several basic parts each turbocharger has:

Compressor
It draws the air in, accelerates and expels it into the diffuser (where it is slowed down, while the temperature and pressure
rise).

Turbine
It converts the exhaust gases’ energy into rotational energy, thus moving the compressor.

Bearing system
As the part operates at extreme speeds, bearings are extremely important in prolonging the lifespan of the element. Bearings used are designed in order to withstand such great stress over years of the parts operation.

Of course there is also a number of other elements, including housings, seals, nuts and locks. However, the above components are the most important ones.

Side note: there is a distinction between mechanical supercharging and turbocharging using the exhaust gas. The first one is much less effective and vastly increases fuel consumption, thus the second one is usually the preferable and more common option and it is the one described here.

Advantages

There are several advantages of using turbocharged engines in comparison with naturally aspirated ones.

Power output
With turbocharging, the engine is able to achieve the same power output as larger engines not equipped with the part. Therefore more powerful engines can be installed in same-sized cars (or simply: smaller cars can be more powerful).

Weight of the engine
As a smaller engine can perform as good as a larger one, its weight is lower as well. Manufacturers can therefore decide to create more powerful engines or minimize the space required for the installation of a very powerful, turbocharged engine.

Noise
Another result of designing smaller engines is less noise generated. Smaller size results in smaller area generating the noise.

Emission of exhaust gases
In contrary to standard, naturally aspirated engines, turbocharging uses some of the exhaust fumes, which are normally wasted and lost. Less emission is also the result of usual lower fuel consumption.

Fuel consumption
Gas energy (from the exhaust) is reused – supplied to the engine.

There are also additional advantages, such as better performance of such engines in higher altitudes. Other engines loose power, as on higher altitudes the atmospheric pressure is lower. With turbocharging, which compresses the air, there are virtually no losses in power. Or at the very least – they are not noticeable while riding.

 

Rigorously tested

It is true, that a turbocharger operates in extreme heat and at extreme speeds. However, it also undergoes rigorous, thorough testing prior to its production on a mass scale. For example, during the testing phase all mechanical and thermal loads are simulated to verify whether the part will operate properly and will be able to withstand them.

An interesting test is called a “containment test”. In it, the turbine is accelerated to such extreme speed that one of the wheels (turbine or compressor) bursts. After that it is verified, whether the housing has been penetrated. If not – the test is passed.