The flaps are stowed during normal vehicle operation.
Race car roof flaps.
Following rusty wallace s crashes at daytona and talladega penske racing designed the original roof flaps.
A roof flap is an aerodynamic feature on race cars mainly stock cars which functions as an emergency spoiler to prevent the vehicle from lifting off the ground.
However in certain situations e g if the vehicle goes into a spin particularly if it is facing backwards the flaps deploy to disrupt the air flow over the roof and reduce.
Before this when the cars spun out at high speeds more than 195 mph 324 kph they would often fly into the air once they had rotated about 140 degrees.
In 1994 nascar introduced roof flaps to the car which is designed to keep cars from getting airborne and possibly flipping down the track.
Thus after development by roush racing the roof flaps were born.
Ultimately a roof flap system was produced that has significantly reduced extreme yaw lift in race cars.