BMC air filter box, CDA Carbon Dynamic Airbox BMC is one of the world's leading players on the market for vehicle air filters, suitable both for street use and for racing at the highest level. BMC's air filter boxes combine several advantages: air flow, filtration, a supply of cold air and an improved appearance. These patent-pending filter boxes are the right choice where no model-specific solution exists, or where an open filter cannot be positioned so that it receives sufficiently cold air. The closed box with its air snorkel solves many problems and is regarded as a market-leading arrangement. The filters in the boxes are supplied pre-oiled and are ready for use straight away. They can be taken apart and cleaned easily when required. The filter boxes can be used together with a mass air flow sensor. BMC air filters are made from a cotton material that offers good permeability, while the combination of several oiled cotton layers stops contaminants and dirt from 7 microns upwards. Synthetic filters normally stop contaminants from 80 microns upwards. With today's technology there is no better filtration system available. All BMC filters are washable. Dedicated cleaning agents and oil are used for this purpose. Choosing a filter: The dimensions of each filter are given in the drawing and the specification table. Choose a filter with the highest possible air flow that still allows correct installation*. Air flows are shown in the diagram and in the specification table. Note: the graphs for these filter boxes apply to the complete system including the snorkel, so they cannot be compared directly with the graphs for the open filters. * Most engines perform best with the lowest possible restriction on the intake side. Choose a filter with the highest possible air flow that can also be fed with the coldest possible air. The routing of pipes and hoses from the air filter to the engine is very important. Use as few sharp bends as possible to achieve a low pressure drop and an even air flow to the intake or turbocharger inlet. A wide range of aluminium pipes and silicone hoses is available for building this. If the supplied snorkel is not long enough, or the system needs to be extended for another reason, air hoses are available for this purpose.