I’ve been a car guy for quite some time but I’m a bit embarrassed that idrk how they exactly work. All that ik is that they give you boost and that somehow makes you faster 🤦♂️
In: Engineering
Chargers work by compressing the air before it is mixed with fuel inside the cylinder, more air means more oxygen, and more oxygen means a hotter and more energetic fuel combustion leading to increased engine power output (this is the same reason why ICEs have a higher power output in cold weather, because cold air is naturally already more dense than hot air).
The only difference between the two types is how they are driven, a supercharger is mechanically coupled to the ~~driveshaft~~ crankshaft of the engine, a turbocharger (as the name suggests) uses a small turbine that is driven by the engines exhaust.
Superchargers and Turbochargers work by using a compressor to get extra air into the engine. More air means more oxygen means more effective combustion means more power.
They work separately though. A supercharger uses a compressor that is driven by a belt directly hooked to the engine, while a turbocharger uses the engine exhaust to power the compressor.
This means that a supercharger is taking some of the power directly created by the engine to produce the effect, while a turbocharger uses otherwise wasted energy.
Internal Combustion Engines (ICE) work by injecting a fuel-air mixture into the cylinder and then igniting it, that causes an explosion that moves the piston and turns the engine. This happens so many times as you drive, it’s going nonstop at a high rate.
Adjust the amount of air and fuel you push in, you can get more or less power.
Turbochargers use the exhaust gases from prior ignitions to spin a turbine that then takes new air and forces it into the engine harder. More air, fuel in the mixture = more power.
Superchargers similarly are used to specifically inject more air into the situation, but instead of using exhaust gas to push the turbine, they use a belt tied to the engine.
Turbos are way more efficient, better for fuel economy and such, but they require the engine to be rev’d up and working first, so there is a lag time before you get the turbo’s added power, hence “turbo lag”.
Supers dont have that lag because they are driven right by the engine itself, but they aren’t as efficient because they are causing a parasitic drag on the engine to run. They give you more power, but it’s more “work” for the engine to run them so you lose fuel efficiency.
engines mix air and fuel to burn to generate power
if more air and fuel going in, more power
how to get more air? chargers suck more air into the engine with a turbine
then more fuel gets mixed with more air that’s being sucked in
more air and fuel going in, car go faster
simple as
The amount of power an engine produces on each stroke depends mostly on the amount of fuel and air you can get inside the cylinder. For fuel it is quite easy, you just pump in more using a small fuel pump. But that extra fuel has to be accompanied by a proportional increase in the amount of air, as there is an ideal ratio of fuel to air that provides the most amount of power.
This is where you run into a problem. You see, naturally aspirated engines (not turbocharged or supercharged), use the weight of the atmosphere to push air into the cylinder. So the only way to get more air into a cylinder, would be to change the atmospheric conditions, which may prove to be difficult.
This is where forced induction comes in. Basically, you use a small fan to force more air into the cylinder. Add more fuel – and bam, you’ve increased the power output with the same displacement engine.
Both turbochargers and superchargers have this small fan. Where they differ, is what makes the fan spin. Turbos use the exhaust of the engine to spin the fan. The advantage, is that the energy is “free”. The exhaust gases would be wasted otherwise. The disadvantage is that it may take some time for the engine to increase its RPM and put out enough exhaust to make the turbo effective. Superchargers are connected directly to the engine (usually through some pulleys), so as soon as the engine RPMs increase – the fan spins up immediately, making the whole system more responsive. The disadvantage is that superchargers are generally less efficient, as they usually rob the engine of a bit of power, to then increase its output through forced induction.
I think the problem stems from understanding what we mean by ‘compressing’ the air, basically a turbocharger or supercharger is just a fan that vacuums up atmospheric air and presses it into the intake manifold. The basics are all the same, as the cylinder goes down and creates a low pressure area (because you had one area and then you retracted the piston creating a greater area with the same amount of total air) high pressure air wants to go fill that void. If you have a supercharger/turbocharger, that high pressure air is simply higher pressure than it would be without one because you vacuumed a bunch of air molecules into the intake manifold.
It plays the same essential role as the low pressure compression stages in a gas turbine like a turbofan engine; the air needs to be moving nice and fast and with a lot of force to turn the turbine, so you get a bunch of bladed fans together to compress the air using the energy of the escaping gases to turn a turbine that is connected to the same shaft as the compression stages and ultimately the big fan at the front of the turbine.
The difference with turbochargers and superchargers is that instead of being connected to a shaft like in a turbine engine, it is connected to the exhaust or crankshaft which delivers the energy required to spin the fans to create that pressurization.
Turbos:
Your engine is powered by tiny explosions and the smoke from those explosions gets blown out the engine and is called exhaust. On the way out it pushes past a fan which is spun by the exhaust. That fan is attached to another fan which is designed to suck air into the engine.
With more air in the engine ( and you can also put more fuel) the tiny explosions are more bigger making more powah babeh
Both work on forcing more air into the combustion chamber.
Turbo uses the exhaust gases to spin a turbine connected to another one that sucks clean air in.
Super uses the rotating shaft that the cylinders are connected to to spin a turbine that sucks clean air in.
Downside of a turbo is that it requires a certain amount of gases to engage so it’s slower to activate, whilst on a super it’s always on but it’s constantly using energy from the motor.
Fun fact: with large engines for vessels they use two turbochargers in series to get up to 8 bar of pressure on the inlet manifold of the motor
Basically, they shove more air into your engine per piston stroke, which lets you shove more fuel into your engine per piston stroke. The result is a more powerful engine for the same size of engine.
As an example, say you’re running 1 bar of boost. When the engine takes an intake stroke to draw air and fuel into a cylinder, 1 bar of extra pressure means that there will be twice as much air pushed into the cylinder. It’s the same volume, but with twice as much air in it, and a correspondingly higher pressure. So you can add twice as much fuel to burn. Which means when that cylinder is compressed and ignited, it will produce about twice as much power as the same cylinder if it had no boost.
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