The VS400600 Flow Stack utilizes a 6" (152mm) flanged ID filter. The stack then tapers to a 4" (102mm) OD outlet, allowing you to couple this to any 4" (102mm) induction system. This Flow Stack is injection molded from PA66 Glass-filled Nylon, the same material family used for GM, Ford and others for radiator caps, induction systems, intake manifolds and other engine bay components. The use of Nylon also significantly reduces heat soak, or the amount of heat absorbed by the velocity stack and then transferred to the air. Light weight design reduces overall weight compared to metal counter-parts, effectively reducing mechanical stress on existing air induction system and mounts. The Flow Stack is universal in application, limited only by the space requirements of the air filter and the ability to couple the Flow Stack to your air induction system

BPI 4.0" (102mm) Flow Stack

SKU: VS400600
  • The BPI Flow Stack is a velocity stack designed to optimize volumetric flow rates into your induction system by preventing boundary layer separation at the inlet of your induction system. Both OEM and traditional aftermarket induction systems utilize a filter or filtration system that creates unfavorable geometry that initiates turbulent vortices and eddies at the inlet of your induction system, reducing the effective inlet ID. This turbulent fluid at the inlet is acting like a choke plate on your engine. The BPI Flow Stack takes advantage of the large flanged filter to create a induction system inlet geometry that will eliminate this "choke plate", by preventing the boundary layer separation and resulting turbulence. Each of our Flow Stacks is optimized using CFD (Computational Fluid Dynamics) Software to run flow simulations and ultimately provide you with a performance product that delivers results.