By Dan Jones
Many members of the BMW Car Club of America New Mexico Chapter enjoy personalizing their BMWs including performance enhancements that are considered “Do It Yourself”. One such DIY modification is adding a Cold Air Intake (CAI) system.
BMW has done an excellent job in developing the original air intakes to be as quiet, yet nonrestrictive, as possible. However, cost constraints as well as overall noise and comfort requirements can make the factory intakes less than ideal from a performance standpoint.
Aftermarket cold air intakes provide a less restrictive filter and piping that increases the volume of air inducted by the engine. This allows fuel to burn more efficiently, due to the increased rate of oxygen combustion and may result in increased horsepower. While some manufacturers claim increases of 5 to 20 horsepower with a cold air intake, the reality is there is a modest increase in power, but there is an improvement in overall throttle response. The biggest difference you will notice with the addition of a cold air intake is the induction noise becomes more audible since performance intakes have no sound baffling.
There are several manufactures of cold air intakes for BMW Zs. Examples include aFe Power with a collection of well-known cold air intake systems, GruppeM Carbon Fiber Ram Intakes, Eventuri Carbon Intakes, Racing Dynamics intake systems, AEM cold air intake systems and DINAN has a simple high flow intake for early E85 Z4s that replaces just the top of the stock air box. Most of these are available from a variety of sources and it pays to shop, but be careful with fitment – make sure it is appropriate for your specific car!
Installation of an aftermarket cold air intake system in your BMW is typically DIY. The following is a step-by-step installation of an aFe Magnum FORCE Stage-2 Pro 5R Cold Air Intake System (P/N: 54-11602) on a 2006 BMW E85 Z4 3.0si: (click on any image to enlarge)