With the increase in the addition of turbos in recent years, you may be wondering what is a turbo exactly?
Turbo equipped cars are becoming more popular in the automotive industry. Here is an explanation of what is, and why you may want one.
A turbocharger, or turbo (colloquialism), is a centrifugal compressor powered by a turbine which is driven by an engine’s exhaust gases. (definition from Wikipedia)
So what exactly does that mean?
Basically, air goes into a vehicle through what is called the intake, goes through the motor, and out the exhaust, the way you can feel air if you put your hands over someone’s tailpipe. This should go without saying, but if you go out to check this out, remember it will be hot.
So, a turbo is built into the engine system where the exhaust air exits the engine. The air exits through the exhaust system, some passing through the turbo (the exhaust system is piping for the air to flow through and exiting through the tailpipe).
In the exhaust system is a catalytic converter or two, resonators, and then the muffler. The catalytic converter serves as a filter to reduce unwanted emissions from exiting into the atmosphere, and the resonators and mufflers serve to quiet the sound.
Were you to remove these, you would not believe how loud the engine sound would be by itself.
Hopefully, that gives you an idea of the airflow through a vehicle, which brings us to the turbo (bear in mind it’s a bit more technical, but I’m gearing this towards someone who knows nothing at all about this).
Inside a Turbo and Basic Airflow
Now, the turbo has two wheels inside it, which are separated with their own individual air pathways, inside what are called housings. These two wheels are called the exhaust wheel and the compressor wheel. They somewhat resemble a plane propeller, with many more fins, and there are the turbine (or exhaust) housing and intake compressor housing, which each house the turbo wheels.
Ok, hopefully, that made sense. So the air that exits the engine that goes through the turbo serves to spin the exhaust wheel inside the turbo (similar to if you blow on a pinwheel from the side). This then spins the compressor wheel as they are connected with a shaft.
The compressor wheel is in line with the intake system. If you’re a bit lost here, basically the air comes in through the intake system, goes through the turbo, then through the motor, some passing by the turbo, and out the exhaust system.
Similar to the exhaust system, the intake system is a set of pipes for the air to travel through to go into the motor. There is an intake filter on the end of the intake system, where the air comes in. Some of you may have had your air filter changed (which is a good idea for gas mileage), or even changed it yourself, which is pretty simple.
So, the compressor wheel is in line with the intake system air passageways, similarly, the exhaust wheel is in line with the exhaust system airways. The compressor wheel spins due to the exhaust wheel spinning.
Turbo Adds an Increase in Horsepower
Here is where a turbo gets fascinating. The compressor wheel is forced to spin so fast, over 100k RPMs, that it now compresses the air going into the engine. What does that mean?
Basically, the air going into the motor has added pressure, measured often in psi. This adds extra power.
How does it add power? A combustion engine runs from explosions of gas inside the motor, the explosion causes pressure, which drives the engine parts. This would entail another explanation, so I’m going to keep it on the turbo.
Being propelled by the exhaust wheel, the compressor wheel increases the air pressure (psi) of the air going into the motor. (There is also an intake on the turbo, sort of the opposite idea of your tailpipe which is all the while still gathering air).
Turbo Car – Great on Gas, Efficient and Plenty of Power
On a non-turbo car, also called naturally aspirated, the air just goes in through the intake, then the engine and out through the exhaust, plain and simple.
With a turbocharged system, the air comes in through the intake, goes through the turbo and into the motor, being compressed along the way and exits through the exhaust, also passing through that side of the turbo along the way.
If this has given you an idea of how this works, you can imagine the efficiency of this. It’s self-propelling, powered by the exhaust air which the engine is already releasing.
Now, under normal driving, the turbo won’t compress the air much, if at all. But if you press the gas to the floor, this will cause the turbo to do its work, almost like it activates it when you do this, although the turbo is always spinning and is only passively in the system, when you press the gas pedal to the floor, it increases the power, from small amounts to horsepower that would blow your mind.
So, basically, with just driving around, it will be like any average economy car overall, and then you hit the gas, it has all this horsepower ready to go.
Turbo size affects this though, the smaller the turbo, the sooner it will work, where a large turbo may need a few seconds to fully kick in.
They call this turbo spool, sort of like it’s winding up in a sense getting ready to unleash its power.
I hope this gave you a sense of what it is and how it works.
Turbo Intercooler System
Additionally, to complicate things even further, there is a cooling system in place in turbocharged cars for the air going into the engine.
The compressed air that goes into the motor is now very hot, which isn’t good for the engine, nor the performance.
There is a pipe system that connects the turbo to the motor, in addition to the intake system and exhaust system.
This is generally called the intercooler and intercooler piping. An intercooler is installed somewhere in this piping to cool the air down going into the motor. That basically sums up the basic principles.
So, you have an economical car when just cruising around with a decent amount of horsepower potential just waiting to be used if needed or wanted.
You may notice more cars coming with turbo options, or only turbo, as they are over already pretty common in Europe, for their efficiency.