Air Intake Systems Research Guide

Air Intake Systems Research Guide Glossary Terms

• Air box
• Air to fuel ratio
• C.A.R.B. certification
• Combustion
• Combustion chamber
• Conical
• Engine compartment
• Intake tube
• Magnuson-Moss Warranty Act
• Mandrel Bending
• Throttle body

Air Intake Systems Research Guide Glossary Definitions

Air box

The air box is the part of a factory air intake which houses the air filter. Air is drawn in through the air box and filter toward the intake tube and throttle body.

Air to fuel ratio

The ratio of air to fuel used during the combustion cycle of your engine. Mixtures heavy on fuel are called "rich," mixtures light in fuel are "lean." Engines come with a pre-set programming of air to fuel ratios, known as a fuel map. Your engine senses the amount of air entering the combustion chamber and responds with the corresponding amount of fuel based on the correct ratio.

C.A.R.B. certification

C.A.R.B. certification is a distinction earned by products that meet the requirements, guidelines and limitations regarding emissions as set by the California Air Resources Board. Items which are C.A.R.B. certified or exempt have satisfied the toughest emissions laws in the U.S., thus are emissions legal for use in any of the 50 states.

Units with C.A.R.B. certification or exemption bear a seal with a serial number of C.A.R.B.'s approval. This number must be present on the performance product at the time of smog or other emissions inspections in order to pass.

Combustion

Burning of the air/fuel mixture in the combustion chamber that generates the energy necessary to run your engine. The mini-explosion in a combustion engine is triggered by a spark from the spark plugs that's added to the compressed air/fuel mixture at the top of the piston cycle. Timing and a proper air/fuel ratio are critical to the power gained during combustion.

Combustion chamber

The space above the piston when it is at top dead center in the compression stroke. The chamber is formed at the exact time of combustion, when the explosion of the ignited air/fuel mixture generates the energy to drive the compression stroke and piston movement within the cylinder.

Conical

A shape identical to or resembling a cone. Performance air filters take advantage of their conical shape for improved air importing, increased filtration surface area and boosted breathability.

Engine compartment

The space beneath your hood and bordered on the sides by the front wheel wells that contains your vehicle's engine. Stock air intakes are confined to the engine compartment, and may require odd shapes and tube networks to fit. Performance air intakes can either be models that reside entirely inside the engine compartment, or some units (cold air intakes) run the air box underneath one of the wheel wells to draw in cooler air.

Intake tube

In an air intake system, the intake tube connects the factory air box or performance filter to the mouth of the throttle body. Intake tube designs can vary greatly. Stock models typically feature a number of bends and a smaller tube size. These design characteristics of stock intake tubes help the intake system fit in the engine compartment and reduce intake noise.

Performance intake tubes look drastically different. The tube diameter is usually much larger than a stock part, and bends/turns in the tube's shape are minimized to improve airflow. Materials and particular design characteristics vary by model, as manufacturers do what they can to maximize performance.

Magnuson-Moss Warranty Act

(US Code - Title 15, Chapter 50, Sections 2301-2312)
Legally, a vehicle manufacturer cannot void the warranty on a vehicle due to an aftermarket part unless they can prove that the aftermarket part caused or contributed to the failure in the vehicle. If your vehicle manufacturer fails to honor emission/warranty claims, contact EPA at (202) 260-2080 or www.epa.gov. If federal warranty protection is denied, contact the FTC at (202) 326-3128 or www.ftc.gov.

Mandrel Bending

This type of bending is the least restrictive and will give you the most performance because the pipe's diameter remains the same throughout the bent areas. To keep a pipe's size uniform, a flexible rod called a mandrel is inserted inside the pipe before it is bent. With the mandrel inside, the pipe can be bent without crushing in on itself. This is critical, as a crushed pipe will diminish airflow.

Throttle body

The throttle body is the valve connecting to the intake tube that regulates airflow into the intake manifold, where air is then distributed to the cylinders.