In 1994 nascar introduced roof flaps a safety device designed to keep cars from going airborne and tumbling over the track.
How do roof flaps work.
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.
Teams buy roof flap assemblies from roush yates.
The flaps are stowed during normal vehicle operation.
Roof flaps are two plates located on the roof which measure 12x8 inches 30x20 cm and are depolyed as the car is either sideways or going backwards at high speeds.
Roof flap spacers are metal disks that sit in the tray and give the roof flaps something to rest on so that they remain level with the roof surface.