How exactly does a car’s turbo work? What does it do, and why the all the fuss over turbochargers?
A Turbocharger is a forced induction system. Basically, as the name suggests, it is a power enhancement. Turbo’s are used to give a greater torque on a smaller engine. They can improve the fuel efficiency and reduce the exhaust emissions as well as performance.
Turbochargers compress the air flowing into the cylinders. The used air and fuel mixture from your cars engine is effectively recycled when it is returned to the cylinders from the exhaust manifold. From the manifold this mixture of gases, fuel and oxygen is forced through a turbine which in turn spins an air pump in the turbo housing. The turbine in the turbocharger can spin of speeds of up to 150,000 rotations per minute (rpm). This mixture of gases, fuel and oxygen are very hot as they are actually being returned to the engine from the exhaust system.
Compressing the air means that there is a larger amount of air being forced into the engine, therefore creating more power. The higher the volume of exhaust gases, the faster the gases drive the turbine, providing more air and producing more power. Once the preset limit is met, the boost pressure is achieved. At this point, the exhaust gas is redirected away from the turbine wheel, thus slowing it down and effectively limiting the maximum boost pressure. This redirection valve is known as the waste gate. This device therefore prevents any over boost from damaging the engine.
The bonus of adding all this compressed air, is that it lets the engine squeeze more air into a cylinder, meaning more fuel can be added. It is then possible to receive more power from each of the explosions in each cylinder. This is then where the power-to-weight ratio for the engine can be improved.
To help reduce the extremely high temperatures in the turbine, many manufacturers are now adding an inter cooler. This is a radiator for air, and is usually situated in front of the main radiator. Some turbo’s also use water-cooling. This is made possible by connecting the turbo to the coolant system, ensuring that the turbo operating temperature is limited by the temperature of the cooling system, which in turn protects the system from any excessive exhaust temperature.
Understanding how a turbo works makes it even more important for car owners to check their existing car warranty documents carefully in order to ensure maximum cover is provided in the event of turbo failure causing damage to your vehicle’s other components. Understanding the how a turbo charger works also helps you drivers understand why car insurance costs rise so dramatically when they try to insure turbo charged vehicles.
It is imperative that the oil supply entering the turbo is full and clean to ensure proper lubrication. If the oil supply becomes too low or contaminated, the turbo unit may become damaged. The most common cause of failure is the lack of lubrication, and as such will fall under neglect, potentially rendering a claim under your mechanical breakdown insurance policy invalid. Large particles can also enter the air stream from the intake, to help avoid this, regularly check the air filter and ducting to ensure that it is clean. It is also possible that engine parts can enter the exhaust system, so regular servicing is essential.