Vibrant's new high efficiency Bellmouth-style Velocity Stacks are ideal for All Motor and Forced Induction race applications. They allow for less turbulent air to enter your motor, resulting in dramatical airflow improvements and ultimately significant horsepower and torque improvements. Also helps reduce turbo lag. Dimensions: ----------Inlet O.D. 3" Bellmouth O.D. 6" * Vibrant Air Filter Part #196 will fit over the Bellmouth Outlet on this velocity stack.