More Air, More Fuel, More Power
Horsepower – it’s the measurement of the power output of an engine. One way to get more horsepower out of an engine is to increase the amount of air and fuel that goes into it. You can add cylinders to the engine or make the existing cylinders larger, but sometimes such changes are not feasible. A turbocharger is often a simpler and more compact way to increase an engine’s power output.
Let There Be Turbo
A turbocharger can boost an engine’s horsepower without increasing its weight, which is a great benefit for any vehicle that needs a boost. Gasoline and diesel engines can both benefit from turbocharging, and not just for better speed and racing performance. More horsepower is often vital to heavy vehicles, such as trucks, that have to haul heavy loads or need extra power in certain operating conditions.
A turbocharger is a forced induction system. It compresses air flowing into the engine. The advantage of compressing the air is that it lets the engine squeeze about 50 percent more air into each cylinder. More air means that more fuel can be injected into each cylinder. More fuel means bigger explosions in the cylinders, which means more power overall than the same engine without a turbo. No system is perfectly efficient, so even though there is 50 percent more air in the cylinders, the turbocharger delivers about 30 to 40 percent more power.
The turbocharger then uses the resulting accelerated exhaust flow from the engine to spin a turbine, which in turn operates an air pump. The turbine spins at up to 150,000 rotations per minute (RPM), which is faster than most engines can go. The temperatures in the turbine are extreme because it is connected directly to the exhaust system, which is partially to blame for the turbocharger’s inefficiency. The turbine in the exhaust flow increases restriction in the exhaust, which means the engine has to push harder against the higher back-pressure to get the exhaust out. This takes power away from the cylinders.
One problem with turbochargers is that the power boost they provide is not immediate when you step on the gas. This is known as turbo lag – the time it takes for the turbine to get up to speed before boost is produced. Once the turbine reaches speed, the turbo kicks in and the car’s power and speed increase.
Advantages of Tubocharging
An advantage of a turbocharger is that it helps engines operate at high altitudes, where the air is thinner. Normal engines have reduced power at high altitudes because it’s more difficult to draw in the thin air. A turbocharged engine might have less power, too, but the loss is usually less dramatic because the turbo can pump the thin air more easily. This often helps vehicles that need a lot of power while operating at high altitudes, such as road maintenance, mining operations, or search and rescue. It also helps at regular altitudes, too, as large vehicles often need an extra boost in certain situations, such as hauling heavy loads or towing.