From the day the internal combustion engine was built, engineers were looking for ways to increase engine power. Many different ways have been developed and tested to achieve this: fuel upgrading, improvement of intake and exhaust phases, improvement of combustion chamber, etc.

One of the easiest and most effective ways to increase engine power is to make air pressure in the intake system. This requires a device (compressor used for it) that blows the air into the engine. Engineers have come up with various types of compressors, part of them have failed due to low reliability, complexity or low efficiency and part of them are used to this day. Each compressor uses energy to build up pressure, reducing engine power and efficiency.

Every  internal combustion engine part of unused energy, such as heat, exhaust inertia, emits to the exhaust system and then to the air. This energy is at best used for heating the environment. In 1925 Swiss engineer Alfred Buchi evaluated this and installed a gas turbine in to exhaust system which turned the compressor through an axis. Turbochargers - this is how these gas turbines were called.
 
Popularity of turbochargers in internal combustion engines has slightly increased, but due to the high price many vehicle manufacturers did not bother to install it. In 1980's developing technologies, i.e. lower cost of a turbocharger production and the increased reliability resulted a breakthrough - Turbochargers were starting to be used more often.
 
The main turbocharger problem which manufacturers are trying to solve is the "turbo lag". Since the turbocharger axle with rotors has a mass, it also has an inertia. This is the main reason for a turbocharger to spin in a bit later than pressing the accelerator pedal. Since 1990 Turbocharger rotors and axle weight reduction research began. Turbochargers have been greatly improved, and simple compressors are practically pushed out of the market.
 
In 1998 turbochargers with a variable flow came into the car market. This has begun a new phase in the history of turbochargers, greatly improving the dynamics and other parameters of turbocharged engines.

 
Turbochargers with variable gas flow have already been tested before, but the tests did not show expected results. The turbocharger manufacturer Garrett developed Variable Nozzle Turbine (VNT), which was first built into the VW-Audi group of cars. To keep pace, other manufacturers - Holset, KKK - began developing this innovation too. Holset has developed a new turbine series of Variable Geometry Turbines (VGT). They were first mounted on Iveco trucks with "Cursor" engines. "KKK" manufacturer had nothing left but to create something that is not patented. After creating a variable geometry turbine and putting it into production, Garrett brought them to court for copying. When KKK had to pay Garret a total of 30 mln. EUR fine, the operation of VGT had been discontinued.

 

Nowadays, the exhaust flow in the turbocharger is controlled by the car's computer, thus ensuring the best accuracy and reliability. It is hard to imagine  modern diesel engine without a turbocharger now.