Lightweight hand laid fiberglass NACA ducts provide positive, low resistance air transfer. Similar to an airplane, drag is also undesirable for a race car. A NACA duct will transfer air into or out of a vehicle with minimal drag increase.
These ducts are easily attached with bonding compound or riveted to fiberglass, aluminum, and steel body panels. Multiple ducts can be mounted side by side when increased airflow volume is required. Reversing the mounting direction will either introduce or remove fresh air. The mounting flanges are approximately 1" wide.
NACA ducts were originally developed by and named for the National Advisory Committee for Aeronautics (NACA) which was the predecessor agency to the National Aeronautics and Space Administration (NASA).