Diandra Leslie-Pelecky - The Physics of Nascar: The Science Behind the Speed

The purpose of racing is to win; you win by beating the competition to the finish line. There are several factors that put you in a position to win; some say its luck, but honestly theres more to it than that! Key factors dictate your successand success ultimately comes from the science behind these factors.

For a race team to win, performance relies upon the driver, the team, and the vehicle. The performance of a race car is a function of:

• Engine power
• Aerodynamics
• Tire grip capability

All of this and a crystal ball will put you in a position to win. Science and the application of its principals is your crystal ball thats racing, its that simple and that complex.

As a driver, I knew how the car felt to me, what it felt like to go fast. It was my job to communicate this feeling to the crew chief so he could adjust the car to keep that feeling throughout a race. The feeling was intuitive; the challenge was in the communication. How do you communicate what you feel and have the crew chief translate this into a mechanical change or adjustment?

When I was a crew chief with Jeff Gordon, we earned 3 championships, 47 wins, and 116 top-five finishes. For us it was part magic and part science. The dynamic of the team, how to work together to achieve a common goal, was certainly a big part of the success and felt like magic; the application of information on how we built the cars and how we raced the cars, decisions made during the race, that was science.

As a team owner, I look at my collective experience as a driver, mechanic, and crew chief, and identifyed a common denominator of success on the race track: It is the systematic application of informationthe science; and the team working in synchronicitythe magic.

Racing is a thrill, in its simplest formbeating everyone to the finish lineto the most complex of How did you beat everyone to the finish line? What changes do we make during the race? and Why are we making them? The Physics of NASCAR helps answer all of these questions. Read on and learn about the science (and magic) of our sport.

Ray Evernham

Have you ever found yourself in the middle of something really exciting and realized that, instead of paying attention, you were thinking about how you got there?

It happened to me on a very cold February evening in Atlanta. To my left, Jeff Gordon was climbing into his No. 24 DuPont Monte Carlo. A few feet away to my right, Elliott Sadler, the driver of the car I had followed around Atlanta Motor Speedway for the last ten and a half hours, was being interviewed. Elliotts crewa great group of guys who had spent the last ten and a half hours trying to work while I asked a lot of questionsdebated tire pressures over the radio. Elliott climbed into his No. 19 Dodge Dealers/United Auto Workers Dodge Charger and fired up the engine. Sitting on the cold pit wall with the crew waiting to see how he would do on the track, I found myself wondering how Ia physics professorended up writing a book about NASCAR.

Absentmindedly flipping through channels the Sunday before Memorial Day 2005, I happened to see a group of six cars rounding the corner of a track. Before I could flip to the next channel, chaos ensued. The back of one car wiggled slightly, and thenWHAM! The car smacked against the outside wall, then careened back down across the track, taking out the other five cars. Brakes screeched, cars spun through the grass, and a giant cloud of smoke rose over the infield.

People like me go into science because we like understanding thingsor maybe its better to say that it bothers us when we dont understand things. I get cranky and frustrated when I cant figure things out. Why would one car, for seemingly no reason, all of a sudden hit the wall?

The lengthy cleanup provided plenty of opportunities to view the accident on replays, which allowed me to dismiss a number of explanations. The car that crashed wasnt going any faster than the other cars. There were no flat tires, no engine failures, and no contact from any of the other cars. As I watched the replaysand then the rest of the raceI became more and more curious.

How do you build an engine that has three times the horse power of a standard car engine and can run at 9,000 rpm for three hours without blowing up? How do you protect a driver from the 1,800F flames of a gasoline fire? How do you construct a car so that the driver not only survives a 190-mph crash, but remembers to plug all of his sponsors before being treated and released at the infield care center?