Some observation on the ACIS high RPM butterfly valve assembly ports; This trumpet-shape area would respond well to simple radiusing the sharp edge..(but above the port area where the plate closes) This would allow smooth and even entry of air at high velocities into the high RPM intake tract with the flow stream adhering to the walls known as laminar or smooth. The present configuration generates a fair amount of turbulence...especially at a 4,000 RPM starting point.