Use a thin piece of metal to artificially lengthen the shocks. When the car hits its first big bump, the spacer flattens out and the car sits lower than the mandated minimum, which means less resistance—and more speed.
A paradox: The technology is both state-of-the-art and obsolete. NASCAR engines use carburetors and distributors instead of fuel injectors and computers, but teams spend millions refining these archaic components. The lighter the better, but that means sacrificing sturdiness. In the words of one engineer, "The ideal engine will run 500 miles, cross the finish line and blow up."
Similar to a standard car's but with much softer pads—they have to last only one race. Drivers are so hard on brakes that the brakes have to be cooled, by either removing tape that normally covers the front grille (increasing air flow but losing valuable downforce) or installing an air pump.
Wider than those on a standard car and without treads. Goodyear makes a specific tire for each track and different tires for the left and right sides since they bear different weight loads in a turn.
The same material used in bulletproof glass and fighter jet canopies. Shatterproof but scratches easily; crews cover it with sheets of hard, clear film that can be peeled off during pit stops to enhance visibility.
Drill holes in the roll cage. The weight saved can then be added as ballast.
Pour 25 pounds of BBs into the frame rails. Once the race starts, open up a trapdoor and dump the BBs—and all that weight—onto the track. Or put BBs or mercury in the rails; when the car turns, this weight shifts to the left side, making it easier to turn. On a straightaway the weight shifts back to the center.
Use a wheel made of metal lighter than what NASCAR requires, such as aluminum. The weight saved can be used as ballast.
Teams build cars as light as possible so they can use as much ballast (lead bars) as possible to get them up to their required weight (3,400 pounds) while lowering the car's center of gravity.
[legal]Roof Flaps and Shark Fins
A car takes on the aerodynamic properties of an airplane wing when it spins out and turns sideways. At that point roof flaps pop up to prevent lift, while shark fins on the rear window upset the airflow over the roof to make the car less prone to liftoff.