So I recently picked up an older VW Jetta/Bora with the 1.8T motor. I think I’ve somewhat gotten the concept, but I still can’t really seem to figure out how the turbo system actually works. What makes the turbine spin? The air from the intake or the air from the exhaust? How is it connected to the exhaust and why?
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The exhaust powers the turbo, which is then used to pull extra air through the intake. The extra air means more oxygen, thus you can combust more fuel and produce more power. The faster the engine is already running, the faster it spins the turbine and the more boost the turbo can provide.
Superchargers, fwiw, also force in extra air but are powered by the accessory belt rather than exhaust spinning a turbine.
The pressure of the exhaust causes the turbo to spin, thus increasing the input of fuel and air into the engine. This is also what creates “turbo lag”. Since the turbocharger is powered by exhaust pressure, the turbo doesn’t have much available power until the engine starts to speed up. Engine starts to speed up, turbo gets more speed, boost goes up, and the engine can generate more power.
This is a pretty easy one.
The more air you can provide an engine, the better.
A basic combustion engine will suck in air when the cylinders go down.
But more is possible. When the exhaust gas gets shoved out, it’s moving pretty quickly. Normally that’s lost energy. So instead, if you put a small impeller blade. (a bit like a complicated wind turbine blade) in the flow of of exhaust gas you can get it to spin. Attach it, via a shaft and a few bearings, to another impeller blade to the air intake to your engine, then you can literally pump air into the cylinders. That gives you far more air, which means you can burn less fuel for the same power, or you can put in more fuel to get more power.
Youll get a lot of explanations about this!
My simplistic explanation is that the engine sucks in air, mixes it with gas, burns it then pushes out the exhaust.
With a turbo, the exhaust gets reused and is used to move an impeller sucking in fresh air forcing it into the motor thus causing more air and more fuel to be forced into the engine thus causing more powah babyyyyy! Hope that helps!
Exhaust gases are hot and moving fast when they get pushed out of the engine. That heat and velocity is energy, and that energy just gets wasted if it’s allowed to simply go out the tailpipe. Instead, you can run that exhaust gas through a turbine, which makes the turbine spin, and the other side of the turbine compresses the intake gases.
Compressing the intake gas means you are stuffing more air into the engine, and an engine is, at base, just an air pump. You put as much air as you can into the engine, add fuel, burn it, and use the heat and pressure of the burning gases to push the pistons down on the power stroke.
So a turbo uses the exhaust gases to pressurize the intake gases and get more intake air into the engine. More air in means more power.
The **turbine** is spun up by exhaust gas, the **compressor** spins to pull air into the intake.
The turbine and compressor are like a mirror image of each other. As the turbine is spun by the exhaust it transfers that spinning motion to the compressor which is like a fan that blows air into the manifold.
As for why, air and fuel need to mix together to make the engine go. The more air you can introduce the more fuel you can mix it with and the more power you get. Using a compressor to shove air into the manifold at greater than ambient pressure is one way to do this.
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