You ve probably noticed that if your car windows are open fresh air gets sucked in.
Purpose of a roof scoop.
In almost every case a large naca duct will provide more than sufficient airflow without increasing drag raising the boundary air thickness or causing turbulent airflow.
This is because there s a negative pressure created by the vacuum bubble behind the trunk.
The main reason for having a roof scoop on a rally car is to actually pressurise the interior of the car slightly.
I have no idea what good a roof scoop could do.
I explain the basics of how the airflow works around.
Hood scoops are for cooling the engine or engine components.
Getting back to aerodynamics today i explain how hood scoops and bonnet vents work for road and track.
It cools off an appropriate spot when you start to get hot headed.
If the car was a rear engined air cooled engine car like an old vw bug it could be used to force cooling air over the motor.
Also on mid engined cars the roof scoop is the air intake.
This small increase in pressure works wonders to keep out dust and sand from the rally stage.
What are roof scoops for.
On a rally race car a small roof scoop creates positive pressure in the cabin pushing dust out of window.