NASCAR Racing: taping, rear tires, downforce

Question
why do they put the tape on the grill does the car go faster when it runs hotter

Answer
Hi David,

They put the tape on the grill to affect the car's performance, obviously.

More tape:  Less air to the engine, engine gets hot and has the possibility of blowing up.  But it also give an areodynamic advantage to the car.  The wind pushes the nose of the car down on the track more.

Less tape:  Less "downforce" to the nose of the car.  It may feel looser which results in a worse handling racecar.  However, it allows more air to the engine which may allow it to run a little, little bit faster.

They adjust this based on how a car is handling.  If it is loose, which means the front end keeps turning into a turn long after the rear tires stop, then they will add tape.  If the car seems slow or the handling is really good and they think they can afford to lose some handling in return for speed, they will take tape off.

Hope i helped!
Coy Jordan