Similar to an airplane, drag is undesirable for a race car. Every bit
of drag on an airplane, a rocket or a race car increases the amount of
fuel consumed and limits
the maximum speed. Launching spacecraft is expensive,
which makes minimizing drag critical. A NACA
duct transfers air where needed in or out of a vehicle with
minimal increase in drag.
They are easily attached with
bonding compound or riveted on fiberglass, aluminum, or steel body
panels. Multiple ducts maybe mounted side by side when increased airflow
volume is required.