Your car’s air intake system does one thing – to draw air from the outside of the vehicle, into your engine’s combustion area. Which is why it is called “air intake” system in the first place.
However, most of you who are reading this post are probably not aware on what it is and how it works on your car. So let met help shed some air intake system 101 tutorial on you guys and help you learn more about your vehicle.
A Bit of History
Engineers first designed air intake systems as simple “air inlets” that is directly connected to carburetors, which was designed and implemented in 1915 by Packard Twin Six.
Such system thrive for decades until in the 80’s where intake systems where redesigned and composed of moulded plastic intake tubes and cone-shaped cotton gauze air filter.
In the early 90’s up to this day, air intake systems are designed to compliment the ever growing need of power, designed to for the sport compact market of Europe, US and Japan.
With continuous technological advancements, air intake systems varies from car to car with some having metal tubes, cold air intake or even having a factory oil catch can.
Why Does Air Intake System So Important?
As mentioned above, an air intake or “inlet” system allows air (or oxygen) to enter the engine. When sufficient or enough air is delivered into the engine, it mixes with fuel that initiates combustion. This process occurs in the engine’s combustion chamber.
As combustion kicks in, it helps the engine to run smoothly given the right amount of air and fuel ratio is achieved. For centuries, automobile’s air intake system has evolved ranging from old designed carburetors to technologically advanced turbocharged engines.
Air intake system of cars today varies due to their designs. But mostly are consists of:
- Air inlet duct
- Air cleaner / filter
- Mass air flow sensor
- Throttle
- Intake manifold
So basically, air is first drawn inside the air inlet housing, then filtered by air cleaner, goes through the mass air flow sensor, then goes through the throttle body, and lastly enters air passageways (intake manifold) that lead to the cylinders where combustion occurs.
Air Cleaner / Filter
When air enters the air inlet duct, it comes with different kinds of debris like dust, sand, leaves, bugs and even stones. That is where your air filter comes in.
Air filter comes in different sizes and designs, but they only do the same task – to clean the air that goes inside the engine.
MAF Sensor
The mass air flow sensor or simply called as “MAF sensor“, is an electronic component located after the air filter box and is designed to “calculate” the right mass of air entering a fuel-injected internal combustion engine.
There are two types of MAF sensor – vane type and hot wire sensors.
Vane type MAF sensor uses a flap that is pushed open by the air entering the engine. So the more air, the more the flap is pushed back. To get accurate measurement, another vane is found after the main vane, and is located in a closed chamber which dampens the movement of the vane.
The hot wire MAF sensor on the other hand, uses a series of wire strung in the air stream, hence it is called “hot wire”. Mass is measured through the electrical resistance of the wire by means of its temperature. The higher the temperature the wire gets, the less electrical current is flowing through the circuit.
When the air flows through the wire, it cools hence reducing its resistance. This allows more current to flow through the circuit.
Throttle Body
The MAF sensor only lets the right amount of air into the passageway going to the throttle body. This part controls the amount of air flowing into an engine’s combustion chamber.
It basically consists of a throttle plate (some calls it butterfly or flap) that rotates on a shaft, an electric motor or for older engine models, a cable mechanism attached to the accelerator pedal.
Speaking of the accelerator, when it is depressed, the throttle plate opens and allows air to enter the engine. And when the pedal is released, the throttle plate closes which prevents air from flowing into the combustion chamber.
In other words, the throttle body controls the rate of the engine’s combustion, which is related to the speed of the vehicle. The little you depress the pedal, the slower the car move. But the harder you depress the pedal, the faster the car accelerates.
Types of Air Intake System
There are several types of air intake system that were introduced through the years – carburetor type, naturally aspirated, and forced induction intake systems.
Carburetor
I have discussed above that carburetor-based engines were the first designed air intake systems in vehicles. A carburetor is a device that mixes fuel (gasoline or diesel) into the incoming air for better and efficient combustion.
Its airflow going into the carburetor is controlled by a butterfly valve or sometimes also called throttle valve. The fuel is then added to the mixture through carburetor venturis.
Naturally Aspirated
Most cars today are naturally aspirated as they don’t use carburetors anymore. Instead, they use a dynamic force to move air into the cylinders.
Also known as normally aspirated engine or NA, this type of air intake system uses an internal combustion engine where air intake depends solely on atmospheric pressure and doesn’t use forced induction system (which is my next topic below).
So basically, any engine that is not turbocharged to supercharged has a naturally aspirated air intake system.
Forced Induction
In contrast with naturally aspirated engine, forced induction involves mechanical devices which “forces” air into the cylinders.
The more air in forced into the engine block, the greater the density of oxygen which allows greater expansion. The result? Greater force or power and more torque!
There are two types of forced induction air intake system – turbocharging and supercharging.
You probably heard turbocharging from movies and Youtube videos. It is a device which reuses the exhaust gases coming from the engine to get more air into the combustion chamber. This results to more power.
One noticeable disadvantage of this system is turbo lag, where there is a delay in the time between the depression of accelerator and the time when the turbo kicks in. Though this may be absent from high-end super cars, most daily driven cars that has turbo have this issue.
What about supercharing air intake system?
Supercharger is another device that has similar process, except that it is driven by the engine’s crankshaft rather than by the external gases.
There are two main advantages of supercharger over a turbocharger – it has no lag, and it works even at low RPM.
Conclusion
So there you have it! I hope I laid all the information you need about your car’s air intake system. So which type of air intake system your car have? Have a look at your engine bay and pinpoint every part of the system and know what type of air intake system your car use!
