Cast Aluminum Intake Elbow Improves Airflow 45% Over Stock Includes 3 Drilled/Tapped Ports Why use cast aluminum? S&B chose to manufacture our Intake Elbows out of cast aluminum because you need a part that delivers extreme performance without the risk of it bursting in the field. While we too liked the idea of using a composite material to make our elbows, trust us, it's not worth the risk.