The engine in your car actually has to breathe in order to run well. Your car inhales through the air intake system and exhales through the exhaust. The air intake system is going to be the focal point for this article.
The intake is designed to perform two basic functions for your engine: get air into the engine and keep the air clean. For our purposes, we will refer to these functions as flow and filtration.
Flow is simply a measure of how much air a filter an intake will allow into the engine. For the most part, an increase in air flow means an increase in power as more fuel can be used to create a stronger detonation in the cylinder. A bigger “boom” produces more power. Restrictive or dirty air filters can have an extremely negative impact on engine performance. To get an idea what restricted air flow feels like, put a towel over your mouth and run to the end of your street and back—we don’t actually recommend you do this unless you enjoy passing out in front of your neighbors.
Filtration is a measure of how well a filter prohibits dust, dirt and other foreign matter from entering the combustion chambers in your engine. Your engine is designed to run on air and fuel—it doesn’t want to try to burn up dirt from the construction site you are driving past. If you have ever accidentally inhaled a bit of powdered sugar from that morning donut, you know what it feels like to cope with extra particulates (cough cough).
Air filters typically use cotton gauze, paper or foam to trap foreign debris before it gets sucked into your engine. Each material provides varying degrees of flow and filtration. The stock filter on many applications is paper. Paper tends to filter better than foam and cotton, but foam and cotton tend to flow better than paper.
The filter is only one of the two primary components in an air intake system; the other component is the tube and housing (if equipped) through which the air flows once it passes through the filter. Tubes and housings come in multiple configurations and are typically made of plastic or aluminum. The intake tube and housing is designed to route as much cool air as possible to the engine. Intakes are often designed to strategically place the filter in an area of the engine compartment where the ambient air temperature is as cool as possible. Some intakes include housings that surround the filter to provide both greater protection and “forced” air flow.
Companies like K&N, Airaid and AFE produce a wide variety of filters and intakes for vehicles of all types. These aftermarket systems tend to flow better than factory units while continuing to filter extremely well. If you are looking for an easy do-it-yourself performance upgrade, a new air intake system could be just what you need. Bolt one on and breathe easy.