The Science Behind Motorsports

Science is interdisciplinary, advancing the fields of medicine, agriculture, and many others.  Science is all around us. It’s in everything we do, from cooking and cleaning to transportation. And stock car racing, North Carolina’s official state sport, would be nowhere without it. 

You may ask yourself how science plays a role in stock car racing. The answer is simple: innovation and the ambition to win. As stock car racing gained popularity throughout the states, on December 14, 1917, a meeting held in Daytona, Florida envisioned the start of the National Association for Stock Car Auto Racing(NASCAR).  It wasn’t until later in Wilkes County, North Carolina, beginning with hauling illegal moonshine and using those same cars for recreational use. After years of traction, Wilkesboro Speedway held its first race on May 18, 1947.

While stock car racing gained garnered more demand,  well-known drivers started popping up  from across the state. There’s Richard Petty from Level Cross, Dale Earnhardt from Kannapolis, and Phillip” Pee Wee” Jones from Clemmon, to name a few.

 As Prohibition passed, many former moonshiners turned to stock car racing.  Many of these drivers came from poor economic backgrounds, meaning they had to be resourceful to fix arising car troubles. Lacking the funds to outsource labor or being so geographically isolated. A do-it-yourself approach to mechanical engineering became the norm among drivers, requirng both physics and aerodynamics knowledge.

Some had help from well-known mechanics; Florida native Ray Fox. Fox is known for jump-starting many NASCAR favorites, including NC natives Herb Thomas and Junior Johnson.   In 1960, Fox built the Chevrolet that won Junior Johnson the Daytona 500. In an interview, Johnson said, “Chevrolet was my favorite engine because of its options. You could improve it in so many ways. The 350 was best because it was easy to work on, and you could make more horsepower.”

 According to Auto How Things Work, you can expect a NASCAR engine to be large, have up to 750 horsepower with similar parts to a street car engine with modifications to make sure it can withstand high temperatures and speeds. A series of tests are then performed to test power output and make sure there’s no abnormal wear. After that, the car is racetrack ready!

It all boils down to the need for speed and the lack of aerodynamics can certainly interfere. Leslie-Pelecky Diandra’s book, The Physics of NASCAR: The Science Behind the Speed explains that the car needs friction to move, however there is bad friction(drag) and good friction(downforce).  Drag is friction between molecules and against the car's motion, causing the car to slow down. The air density, speed and car shape will determine the size of the drag force. So, things like the windows and wheel openings will minimize drag, but ultimately downforce is the best way to counteract the restricting friction.  Downforce is the force that gives the car more grip on the track by pushing the tires harder into the track. There are many design modifications to increase downforce, but this is often accomplished by adding a rear wing to the back of the car. With a rear wing, the air moving under the wing moves faster than the air moving over the wing.  Diandra notes that with this configuration, stock car designers make it, so the car’s entire body is used to increase downforce. 

There is science behind the mechanics of the cars, but the tracks themselves require detailed design as well. Each track is different, but most will include banks and curves. A bank is sloped upward towards the middle of the track, designed to hold objects such as cars and people on the track at high speeds, reducing the chances of the car going off the track. A curve is a bend in the track that has no upward slope.  Charlotte Motor Speedway is a 1.5 mile speedway featuring banking in the corners at 24 degrees and banks in straightaways at five degrees.  To navigate through the bank, centripetal force is employed to change direction. This means that the force makes the car follow the curved path, and the force pushes inward toward the center of the circle. The driver will feel as though they are being pushed backwards, in the opposite direction of movement, even as they accelerate forward through  the force.

That’s just a small glimpse into the many ways that science plays an important role in the success of stock car races. One thing is for sure: North Carolina has continued to prove its importance to NASCAR history. The Moonshine and Motorsports trail highlights its fascinating past, along with its future, including the reopening of the North Carolina Wilkesboro Speedway. The sport's popularity has remained steady throughout the years, attracting fans from across the state.  Stock car racing is here to stay and it’s all thanks to science. 

References 

Jones, A. B., & White, R. (2007). All around the track: Oral histories of drivers, mechanics, officials, owners, journalists and others in motorsports past and present. McFarland & Company, Inc., Publishers.

Ray Fox: NASCAR Hall of Fame nominee. Nascar Hall of Fame. (n.d.). https://www.nascarhall.com/hall-of-famers/nominees/ray-fox 

Woodin, A. (2022, September 14). How NASCAR’s science of speed is continually evolving. USA Insider Official Site. https://www.usanetwork.com/usa-insider/how-nascar-science-of-speed-is-continually-evolving

Leslie-Pelecky, D. L. (2009). The physics of NASCAR: The science behind the speed. Plume.