Every fuel-powered engine takes in air and fuel and combusts them, before shooting the remnants out as exhaust. To get more power from an engine, you will need to burn more fuel (and do it faster). But when you have a set volume of area in the engine where the fuel and air can go, how can you burn more? Bigger engines that could hold larger volumes of fuel are not the answer, as they very slow to start and are not practical in size (since it would take more energy to move a larger piece of equipment, voiding out any possible gains). So how do we maximize the power an engine can produce when space is limited?
The answer to this problem was discovered in the early 1900s. Since air and fuel are both brought into the engine and both take up space in there before being combusted, to get more fuel into the engine (and thus more power), engineers were able to develop a system that compresses the air so the oxygen molecules are closer together, which creates more space for more fuel in the same area that was there before. This is now referred to as a turbocharger.
A turbocharger sits between the exhaust and the engine and is connected to both, as well as the air intake for the car. The turbocharger itself looks like the shell of a snail. The two main parts of a turbocharger are a turbine and a compressor, and each have an important step in the process.
• Step one: the turbine. Exhaust gas from the engine is pulled into the turbocharger and is used to spin the turbine. A turbine is a machine for producing continuous power in which a wheel revolves because of a fast-moving flow of water, steam, gas, air, or other fluid. In the case of the turbocharger, the exhaust in the fast-moving flow of gas that turns the turbine. The exhaust is brought to the turbine through the turbine housing, which guides it to the turbine wheel. After the exhaust is used to turn the turbine, it is shot out the back of the vehicle.
• Step two: the compressor. The turbine—which is now spinning very fast thanks to the exhaust gas—then turns the compressor wheel. The high-velocity spinning of the compressor draws air into the compressor. Once the air is in the compressor, it is compressed and diffusion takes place. Diffusion is the process that occurs when high-velocity, low-pressure air is converted to high-pressure, low-velocity air. The high-pressure, compressed air is then pushed toward the engine.
To prevent air from going back from the engine toward the compressor when it is highly pressurized, when the throttle is lifted off a blow-off valve relieves the pressure of the air and releases it out of the engine. This valve creates that iconic turbocharger hissing sound.
Since the molecules in the air that exit the turbocharger are so close together, they have more friction with each other, which causes the air to be at an extremely high temperature. Part of the turbocharger turns red-hot in the process of compressing the air. In many engines with a turbocharger, an intercooler intercepts the air before it reaches the engine to cool it with coolant. This helps the air become even more dense than it was when it was first compressed since hot oxygen molecules move more and take up more space than cool oxygen molecules.
The engineers who worked to develop and rebuild turbochargers and diesel engines had the same goal: to get more powerful vehicles and equipment accessible to ordinary people instead of reserving them for large industries. While the turbocharger is used for larger commercial purposes such as aircraft, agricultural machinery, and marine-based diesel engines, it is also found in many diesel-powered vehicles, motorcycles, and an increasing number of petrol-powered vehicles. It seems as though the hope of those early engineers has been achieved.
At Goldfarb & Associates, Inc., we offer the best in new, re-manufactured, and used turbochargers and diesel parts. We have a turbocharger for any diesel engine. If you need a turbocharger, you can search our inventory online or call us at 301-770-4514.
