Automotive Systems/Intake System

From Wikibooks, open books for an open world
Jump to navigation Jump to search

The intake system is responsible for delivering oxygen, which is necessary for combustion. An intake system generally comprises an air filter, a throttle, and passageways for air to reach the cylinders themselves.

There are several main types of intake systems. Carbureted, Fuel Injected, Naturally Aspirated, and Forced Induction.



The Carburetor is a device that mixes fuel(Gasoline especially petrol) into the incoming air for better combustion of it. The airflow into the carburetor is controlled by a butterfly valve & throttle valve, and the fuel is added to the mixture through venturis types of carburetor 1.single venturie 2.multi venturie a.up draught b.down draught c.side draught

Naturally Aspirated[edit | edit source]

An engine that is naturally aspirated uses the dynamic forces involved its in own operation to move air into its cylinders.

Simply put, if an engine is not turbocharged or supercharged, and if it does not use NOS, it is naturally aspirated. There are a few exceptions, but they are so rare that it's not even worth going into them.

Forced Induction[edit | edit source]

Forced induction involves mechanical devices which force air into the cylinders. This greater density of oxygen allows for greater expansion, but as the engine block is mostly static, the greater expansion translates into greater force and thus more torque. Both methods of forced induction increase fuel consumption because as more air is forced into the engine, more fuel must be added as well to maintain a safe air/fuel ratio.

Turbocharging[edit | edit source]

A turbocharger is a device which reuses the engine's exhaust gases to cram more air into the engine, resulting in more power.

A disadvantage of turbocharging is that they have lag, which is a noticeable delay in the time between when the accelerator is fully applied and the time when the turbo kicks in. Turbo lag is not noticeable on high quality cars, such as Porsches.

The latest generations of turbochargers come with the "variable nozzle technology", which allows the turbo to regulate the inside geometry of the turbo itself, regulating at the engines need the pressure of the air flow into the combustion chamber, this creates no turbo lag(not noticeable). An increase in HP, torque, fuel efficiency and mileage, are the outcome of this tech. Applicable in both diesel and petrol engine, more common in diesel now a days because of material costs and diesel natural efficiency.

Supercharging[edit | edit source]

A supercharger also forces more air into the engine just like a turbo, except that a supercharger is driven by the engine's crankshaft rather than by the exhaust gases.

A supercharger has an advantage over a turbocharger in that there is no lag. Another advantage is that the supercharger works even at low RPM, while turbos only work at higher RPM.