Everyone knows that frightening feeling of opening your airbox and laying eyes on all the debris and dirt that has somehow found its way past your air filter. On a car like the 911, where the intake is essentially exposed by a screened opening in the rear decklid, it's easy to see how a whole load of garbage can find its way in there. For this reason, the type of air filter you're using becomes even more important. Paper filters do a good job of stopping larger debris, but smaller dust particles and water can very easily find their way through the filter and into your engine, especially on a car like the 911.
BMC performance filters are designed with several key elements that not only stop larger debris, but also provide superior filtration when compared to paper filters. First, the outer frame of the filter is constructed using a proprietary process called "full molding" so that it has no seams, reducing the risk of cracking or breaking. The soft rubber frame also provides a much firmer seal around the edges of the filter, where larger pieces of dirt can sometimes find their way through. The filter element itself is made of a special cotton material that stops even the smallest dust particles without any negative effects on airflow. In fact, the BMC's cotton filter element flows so much better then the stock paper filter that it produces an additional 5-7 horsepower when compared. The two pieces are then held together using an alloy mesh which helps the filter retain its unique shape and also prevents damage from exposure to water, oil, fumes, or larges debris that may enter the airbox. Best of all, BMC filters are cleanable so you'll never need to buy another filter again.