Catégories : Tous - combustion - engines - power

par James McGogan Il y a 3 années

435

Gearboxes/Transmissions

Engines require a mixture of air and fuel to generate power, operating through a series of steps within a four-stroke cycle. The process begins with the intake of air and fuel into the cylinder, followed by compression where the piston moves upwards, compressing the mixture.

Gearboxes/Transmissions

Forced induction systems use various means to shove more air into the engine. This is especially useful at high altitudes, where there is less air to power engines. when an engine isn't equipped with force induction, it is called a "naturally aspirated" engine. Naturally aspirated engines usually have to rely on car speed to get air into them, which means that they can't have as much power.

what is it?

This is where gearboxes come in. If running an engine at high RPM sucks in more fuel and air, why not just keep it at low RPM? Gearboxes can keep the engine at low revolutions per minute while still getting the car to decent speed

Forced induction

different types of forced induction

supercharging

Superchargers take power off the crankshaft of a car and use it to force air into the engine.

Supercharging VS natural aspiration
superchargers VS turbochargers
turbocharging
How do they work?

To run at more revolutions per minute, engines need to suck in more air and fuel to keep the engine going faster.

Engines need air and fuel to make power. They suck these into the cylinders, which then explode them to push the pistons and generate power. The exhaust then goes out of the cylinder and the process repeats.

more info

making power in a standard, 4 stroke, engine(I don't want to talk about rotary or 2 stroke engines right now)
To make power, engines take gas and explode it to push a crankshaft. This is done in a few steps: 1. intake: the piston cycles around and starts coming to the top of the cylinder. a bit of fuel and air is then injected above the piston. 2. compression: when the piston starts coming further up the cylinder, the air and the fuel gets shoved together. 3. combustion: when the engine starts moving downward, the fuel and air mixture is exploded. the gas from this reaction then pushes the piston further down. 4. exhaust: the piston starts moving up again. some valves open and the gases from the explosion rapidly leave the cylinder, just before the intake and ignition start again.

Why do engines make power?

downshifts

downshift technology

why are they hard?

downshifting might sound easy right? just throw the lever into a new gear. but actually, it is pretty difficult to do, especially in an old car.

Gearboxes/Transmissions

Gears

how do they work
types of gears

changing gears

Upshifts
Upshifting helps increase the amount of power going to the wheels so that the car can go faster.
downshifts in a manual
Heel and toe

Heel and toe is a trick that racecar drivers use so that they are more efficient while exiting corners. if you hold the brake while using your heel and toe of your right foot to downshift, you can get into a lower gear for coming out of the corner

older manual transmissions

Hard

modern manual transmissions

Modern transmissions have more assists to help with downshifting so it's easier

changing gears in a dual clutch

Different types of transmission systems

automated manual transmission
an automated manual transmission (AMT) is essentially a manual transmission with a robot holding the clutch and gear lever.

comparisons to manual transmission systems

disadvantages over automatic

Advantages over standard automatic

dual clutch transmission(DCT)
sequential transmission
torque converter automatic
Manual gearbox
automatic transmission
CVT (continuously variable transmission)

why do we need them?

fuel economy
why do gearboxes make cars more fuel efficient?
if cars didn't have gearboxes, the powertrain would get damaged faster. when the engine is trying to force the wheels to turn in too high of a gear, the crankshaft and transmission get put under a lot of stress. having lower gear reductions helps with this
without a gearbox, a car would be hard to start. the gearbox makes the engine turn more times than the wheels in low gears, which helps give it more torque. if this didn't happen, the car would get stuck more easily
Gearboxes also make cars more fuel efficient, because they can keep an engine going fast at low RPM
gearboxes help make a car capable of going faster. without a gearbox, the wheels would only be able to turn as fast as the engine. with one, they can spin faster