Cold air intake
Encyclopedia
A cold air intake is an aftermarket
assembly of parts used to bring relatively cool air into a car
's internal-combustion engine.
Most vehicles manufactured since the mid-1970s have thermostatic air intake systems that regulate the temperature of the air entering the engine's intake tract, providing warm air when the engine is cold and cold air when the engine is warm to maximize performance, efficiency, and fuel economy. Aftermarket cold air intake systems are marketed with claims of increased engine efficiency and performance. The putative principle behind a cold air intake is that cooler air has a higher density, thus containing more oxygen per volume unit than warmer air.
, carbon fiber or Kevlar
). The most efficient intake systems utilize an airbox
which is sized to complement the engine and will extend the powerband of the engine. The intake snorkel
(opening for the intake air to enter the system) must be large enough to ensure sufficient air is available to the engine under all conditions from idle to full throttle.
The most basic cold air intake consists of a short metal or plastic tube leading to a conical air filter. Power may be lost at certain engine speeds and gained at others. Because of the reduced covering, intake noise is usually increased.
Some intakes use heat shields to isolate the air filter from the rest of the engine compartment, providing cooler air from the front or side of the engine bay. Some systems called "fender mount" move the filter into the fender wall, this system draws air up through the fender wall which provides even more isolation and still cooler air.
Aftermarket (automotive)
The automotive aftermarket is the secondary market of the automotive industry, concerned with the manufacturing, remanufacturing, distribution, retailing, and installation of all vehicle parts, chemicals, tools, equipment and accessories for light and heavy vehicles, after the sale of the...
assembly of parts used to bring relatively cool air into a car
Automobile
An automobile, autocar, motor car or car is a wheeled motor vehicle used for transporting passengers, which also carries its own engine or motor...
's internal-combustion engine.
Most vehicles manufactured since the mid-1970s have thermostatic air intake systems that regulate the temperature of the air entering the engine's intake tract, providing warm air when the engine is cold and cold air when the engine is warm to maximize performance, efficiency, and fuel economy. Aftermarket cold air intake systems are marketed with claims of increased engine efficiency and performance. The putative principle behind a cold air intake is that cooler air has a higher density, thus containing more oxygen per volume unit than warmer air.
Design features
Some strategies used in designing aftermarket cold air intakes are:- Reworking parts of the intake that create turbulence to reduce air resistance.
- Providing a more direct route to the air intake by eliminating muffling devices.
- Shortening the length of the intake.
- Using a less restrictive air filter, usually trading filtering quality for increased airflow capacity (this may be of dubious benefit).
- Placing the intake duct so as to use the ram-air effectRam-air intakeA ram-air intake is any intake design which uses the dynamic air pressure created by vehicle motion to increase the static air pressure inside of the intake manifold on an engine, thus allowing a greater massflow through the engine and hence increasing engine power.The ram air intake works by...
to give positive pressure at speed.
Risks
Aftermarket cold air intakes can pose a risk of damage to the vehicle.- HydrolockHydrolockHydrolock is an abnormal condition of any device which is designed to compress a gas by mechanically restraining it; most commonly the reciprocating internal combustion engine, the case this article refers to unless otherwise noted...
- The intake opening is closer to the street than an original-equipment air intake, and more likely to introduce water into the engine when fording streams or flooded roads.
- Noise - Stock air filtration systems usually include resonatorResonatorA resonator is a device or system that exhibits resonance or resonant behavior, that is, it naturally oscillates at some frequencies, called its resonant frequencies, with greater amplitude than at others. The oscillations in a resonator can be either electromagnetic or mechanical...
-based muffling tubes. Removing them reduces pumping losses but increases noise.
- Can void the vehicle warranty.
Construction
Intake systems come in many different styles and can be constructed from plastic, metal, rubber (silicone) or composite materials (fiberglassFiberglass
Glass fiber is a material consisting of numerous extremely fine fibers of glass.Glassmakers throughout history have experimented with glass fibers, but mass manufacture of glass fiber was only made possible with the invention of finer machine tooling...
, carbon fiber or Kevlar
Kevlar
Kevlar is the registered trademark for a para-aramid synthetic fiber, related to other aramids such as Nomex and Technora. Developed at DuPont in 1965, this high strength material was first commercially used in the early 1970s as a replacement for steel in racing tires...
). The most efficient intake systems utilize an airbox
Airbox
Motorcyclists and car enthusiasts use the term airbox for what might more properly be described as an air intake chamber. Older engines drew air directly from the surroundings into each individual carburetor...
which is sized to complement the engine and will extend the powerband of the engine. The intake snorkel
Vehicle snorkel
A vehicle snorkel is the land-based equivalent of the submarine snorkel which allowed submarines to use diesel engines while submerged. Snorkels, when used by vehicles with air-breathing internal combustion engines, allow limited deep fording capability for river crossing or amphibious landing...
(opening for the intake air to enter the system) must be large enough to ensure sufficient air is available to the engine under all conditions from idle to full throttle.
The most basic cold air intake consists of a short metal or plastic tube leading to a conical air filter. Power may be lost at certain engine speeds and gained at others. Because of the reduced covering, intake noise is usually increased.
Some intakes use heat shields to isolate the air filter from the rest of the engine compartment, providing cooler air from the front or side of the engine bay. Some systems called "fender mount" move the filter into the fender wall, this system draws air up through the fender wall which provides even more isolation and still cooler air.