When a racecar is spinning, pressure increases inside a racecar that could cause the racecar to flip. Roof flaps open then this air pressure increases inside the racecar to relieve this pressure and keep the racecar from flipping.
The two flaps that rise when a car begins spinning out of control in order to catch the wind and limit a car's ability to become airborne.
These flaps are sections at the rear of a race vehicle's roof that are designed to activate, or flip up, if the air pressure flowing across them decreases. In the case of a vehicle turning backwards, the tendency for an uninterrupted flow of air is to create lift. The roof flaps are designed to disrupt that airflow in attempt to keep the vehicle on the ground.
When a stock car gets sideways on the track, the flaps pop up and act much like the flaps on an airplane wing, slowing the car and helping prevent it from becoming airborne.
These flaps are attached to the racecarâ€(tm)s roof and are designed to activate, or flip up, to deter the car from going airborne if it should spin around backwards. In the case of a vehicle turning backwards, the tendency for an uninterrupted flow of air is to create lift. The roof flaps are designed to disrupt that airflow in attempt to keep the vehicle on the ground.
These are two rectangular pieces of metal that are on the roof towards the rear of the car. They lie flat when the car is moving forward. However, in the event that the car goes into a backward or sideways spin, these flaps are sucked open to take advantage of the aerodynamics and in turn, keep the car from going airborne.