150mm OD Rampipe Base
The Pipercross 150mm Outer Diameter base found on Pipercross Induction kits is used to create laminar air flow.
Laminar air flow occurs when the air is flowing in the same direction and turbulence is kept to a minimum. Turbulence causes drag which slows the airflow down and limits the flow rate of any induction system.
Filter units without a full radius edge create turbulence, thus reducing their effectiveness.

At the heart of the unique pipercross air filter is a specially developed polyurethane foam which acts as the filtration medium, having both higher performance and life expectancy than paper.

Pipercross reticulated foam is created by a chemical reaction, it is then placed in a gas filled combustion chamber where a controlled explosion burns away any complete cell walls in the material to form a skeletal cellular structure which is strictly quality controlled. This process, which is specified by Pipercross ensures that the foam consists of tiny open cells which trap contaminants.

The cell size of the foam, its porosity, is measured in Pores Per Inch (PPI). Pipercross air filters use up to six layers of foam with varying porosity descending in pore size in the direction of air flow.

The Pipercross filters long life span is due to the dirt storage capacity of the foam cells and the filters construction which means no air passage is blocked until all the cells in a layer of foam are completely filled. It is designed to hold contaminants in the filters outer layer, inner layers act as a secondary measure to ensure an exceptionally high level of engine protection.