Kid Turbo on The physics of Cold Air Intake Systems - The amount of "GO" you get out of an engine is a direct function of the quantity of air and fuel that move through the engine. More air and fuel means more "GO". Today the most popular and unobtrusive way to get more air through an engine is with a cold air intake.
Your car breathes air, a gas(versus a liquid or solid) and gas behaves differently from the other two common states of matter. A simple review of the behaviour and properties of gasses will shed light on how a cold air intake creates more power. Gases, unlike solids and liquids do not have a fixed quantity or shape and assume the shape of the container in which they are held. Gasses have three interworking relationships that rocket scientists and cold air intake guys take advantage of in a cold air intake system: temperature, pressure and volume. A change in one variable will cause a change in one or both of the other two variables until a new equilibrium is achieved. For example if temperature is decreased and volume is held constant then pressure will go down. In the case of a cold air intake which is an open system and has an unlimited supply of gas, pressure will quickly be equalized by more gas filling the fixed volume of the air box. If temperature is increased, pressure will increase and less gas will be available in the air box. The simple rule is as temperature goes down the quantity of gas that can occupy a given space goes up.
The basic cold air intake is essentially a tube that moves the intake location for air flowing into your engine away from the hot thin air that exists around the hot engine surfaces in the middle of the engine compartment to a cool spot in a corner of the engine compartment. When this cool dense air is input into the fixed volume of an engine, it heats up and confined by the walls of the intake system increases in pressure. The greater quantity of air coupled with the right amount of fuel result in improved performance of the engine. The air flow sensor is moved to the cold end of the intake system to allow the car's engine control computer to determine the amount of fuel to mix with the air. This maintains the integrity of the air/fuel calculations.
The effectiveness of a cold air intake system is based on the following factors:
Number of bends in the cold air intake tubing.
Diameter of cold air intake tubing
Length of cold air intake tubing
Smoothness of interior of cold air intake system
Location in engine compartment
Insulation of cold air box from hotter air of engine compartment
Cold air intake manufacturers spend lots of dollars optimizing the trade offs in the factors listed above. Motorweb has a broad spectrum of manufacturers including AEM, Airaid, AFE, Fujita Air, Injen, Neuspeed, Voland and others that will have exactly the cold air intake for your ride. Please search by our most popular vehicles arranged for easy access below or by the cold air intake manufacturer search box to the right.