Car’s mobility is base on the simple principle of internal combustion. As air and fuel are mix a spark ignites the mixture and combustion happens. If the intake of air is inadequate the fuel may not fully burn, leading to low output and if the intake of air is excessive it burns up the fuel rapidly, increasing the fuel consumption rate. Both those conditions result in greater running costs in the short run and damage to the engine in the long run.
The air intake system is what draws the air from the outside and supplies it to the engine. Most vehicle manufactures install system that is best suited for the car, however some drivers wants to enhance the power and fuel efficiency. There are aftermarket air intake systems that can give them those results. The air intake systems can be broadly divided into two categories: cold air intake system and warm air intake system. Each system has its own set of pros and cons and is designed to perform in different kind of environments.
In cold air intake system the cold air is sucked into the engine. Because cold air is denser than warm air it carries a larger amount of oxygen, which increases the efficiency of the internal combustion process, resulting in higher horsepower and torque. In most case drivers feel improvement with the throttle response and fuel economy. However since cold air is directly sucked into the engine, there is always a risk of getting water sucked into the engine resulting in Hydro Lock, a condition where water enter the cylinder preventing the piston to complete a full stroke. Also due to the design of the cold air intake system the stock air filtration system resonator based muffling tubes will be removed causing the noise to increase. The cold air intake systems are comparatively easy to install.
In warm air intake system the warm air surrounding the engine bay is directly sucked into the engine. Because warm air is less dense it contains less oxygen causing the engine control unit to compensate by opening the throttle wider to admit more air. This decreases the resistance for engine to suck in air and allows for the intake of the same amount of oxygen with less friction losses. Result in a gain in fuel economy at the expense of top end power.
The intake system comes in many different styles depending on the brand and can be made from plastic, metal, rubber, silicone, fiberglass, carbon fiber, or Kevlar. The snorkel is the opening of the intake for air to enter they system and should be large enough to provide sufficient air to the engine under all conditions from idle to full throttle. Other features are heat shield: to isolate the air filter from the rest of the engine compartment preventing warm and cool air to mix, fender mount: move the filter into the fender wall to draws air up through the fender while providing more isolation and cooler air, air bypass valve: a filtered spacer that is positioned more into the engine bay, between connected pieces of the cold air intake assembly, prevents Hydro Locking by providing an alternate route for air to come in and eliminating the vacuum that causes water to be sucked into the engine, foam filter: a simple piece of foam that is air permeable and has more surface area for air to enter the engine when the driver accelerates, cloth filter bypass valve: allow air in if the valve is sucked open as result of the vacuum pressure, paper filter: allow very high air flow but does not filter as well as stock filter, and paper cone filter: are made of porous paper and collect dirt and debris as air pass through it.