What is the difference between an engine being turbocharged and supercharged?
A supercharger is a fan that draws power directly from the engine. A turbocharger puts a windmill in the engine exhaust as the power source for the fan. The turbocharger is a bit more efficient, as it’s using power that would be wasted out the exhaust. But turbochargers tend to cost more, and they spin up more slowly than a supercharger. There’s no clear winner, IMHO.
Superchargers are connected to and powered by the engines crankshaft. They compress the fuel and air mixture and force it into the cylinders when the intake valve opens. The throttle response is very quick. In a turbocharged engine the fuel / air compressor is powered by the exhaust gases of the engine. The exhaust turns a propeller on one side of the turbocharger which in turn spins the blades on the other side (the intake side). Turbochargers are harder to make because they must be able to take the exhaust heat on one side and be cool enough for the fuel/air on the other. The throttle response is usually slower on a turbocharger however there are tricks to speed it up some. Turbochargers are also usually smaller and easier to install.
A turbo charger receives it’s driving force from exhaust gases from the engine, and generally have more components such as an intercooler or pressure relief system. A supercharger usually gets it’s power from a drive belt attached to the crankshaft of the engine. They both work by increasing the volume and pressure of air in the cylinder, and raising the air to fuel mixture ratio, improving the explosive power of the fuel and creating more power with each “explosion” in a cylinder.
The turbocharger relies on exhaust pressure to drive a turbine blade increasing pressure at the intake side of the cylinder. The supercharger is mechanically driven from the engine. Beyond a certain point, more pressure is counter-productive, causing premature ignition, and knocking, so additional pressure doesn’t seem helpful. Cooling helps increase the usable pressure. Better? Turbocharging appears to be more cost effective. Supercharging does not have the pedal delay that exists in most turbocharged engines that have to wait for increased exhaust flow to increase pressure. I saw something about an engine available next year that has both. I wait with baited breath to see what they addvertise as the advantage, other than higher cost.
Mechanically, a supercharger compresses air with a positive displacement compressor usually driven from the crankshaft with a belt. A turbocharger compresses air from exhaust gases spinning a turbine that drives another turbine that compresses the air. Performance wise, the supercharger tends to make added horsepower at the lower rpms where the engine is at its weakest. A tubocharger adds most horsepower at the higher rpms where the exhaust gases are the greatest. Which is better depends upon where you want to add horsepower.
