To further increase engine power and performance, the industry has developed the turbocharger, or just turbocharger. This system, patented in 1905 by Swiss Alfred Büchi, aims to overfeed the engines with air, since the fi lling rate of the cylinders, caused by the depression created by the movement of the piston to its lower neutral, does not represent more than 80% to 90% of the unit displacement of the cylinder. In aspirated engines (without turbo), the opening and closing of the intake valves lead to the formation of pressure waves that cause a slight addition of this in the intake manifold, which makes it diffi cult to enter air into the cylinders.
The turbo charger then serves to offer more power without having to increase the size of the engine. Because the yield is directly related to the air mass that the engine can vacuum per intake cycle, the turbo has the mission of compressing the air before it is admitted, resulting in more air mass in the combustion chamber, and more air means that more fuel can be added. There fore, more power is obtained from the explosions in each cylinder. A turbocharged engine produces more power than the same engine without the device. This can signifi cantly improve the weight/power ratio of the engine.
The turbocharger, previously used only in large diesel vehicles and sports cars, is now used in all types, especially those that need less consumption. It is part of the concept of "downsizing", with smaller engines capable of delivering the same power as the larger ones, with benefi ts in fuel expenditure.
The use of turbines is especially important in diesel engines, because by increasing the pressure and temperature inside the cylinders, the risk of detonation is reduced, while the application in gasoline engines increases this risk, which takes more attention in its application in these engines.
| actuators Relief Valve | Wastgate
The Actuator or wastegate is a valve responsible for the control of the pressure in the system, it is possible to fi nd this valve in the vast majority of cars with turbo without variable geometry. This valve reacts to turbo pressure by allowing only part of the exhaust gases to pass through the turbine in order to control the maximum pressure. With fewer gases passing through the turbine, the compressor rotates more slowly stabilizing the turbo pressure. The Actuator forwards the remaining gases to the exhaust manifold. There are actuators internal or external to the turbo. Usually when the cars are equipped with these valves and the turbo moves or if the maximum operating pressure increases, the actuator actuator actuator mechanism may not be suffi cient to work at said pressures and the valve hasto be changed.