Typical air filtration devices create unfavorable geometry that introduces turbulent vorticles and causes a choking point at the inlet entrance. Velocity stacks utilize smooth-radius, larger flange diameter filters to create a geometry that eliminates this choke point, thus vastly increasing volumetric air flow. Each velocity stack is designed to allow optimal efficiency using computational fluid dynamics (CFD) software and is manufactured from PA66 glass-filled Nylon to reduce heat soak but also retain rigidity in a lightweight form.
This velocity stack is intended for use with 3.0" (76mm) OD tubing and a 6" (152mm) ID filter. We use this piece in our 2015+ WRX intake systems.