Air Filters
Everyone claims their air filter flows best, and at the same time removes the most dirt. Think about this. A solid piece of metal will prevent dirt from entering your engine, but it won't flow any air. On the other hand the screen used on your bedroom window will flow a lot of air but won't catch much dirt. There are really three goals involved in air filter selection. - Provide maximum airflow. - Protect against airborne dust particles. - Perform efficiently when dirty. You should try to use an air filter that traps particles over 10 microns. A grain of sand is roughly 50 microns. BMC, who builds a lot of the air filters used in F1, claims they have filters that can trap 7-micron debris and still flow efficiently. Most of the air filter manufacturers though are very reluctant to share this information. K&N told me that it was proprietary information and they were not about to tell me what micron levels their filters ...