Why Don't NASCAR Race Cars Have Doors?

NASCAR race cars don't have doors for a very good reason and that reason is safety. NASCAR race cars are different from the average car and reflect the tragedies that have changed NASCAR forever. They are strong, heavily reinforced, and very safe structures, designed to keep the drivers inside the vehicles and protected from what's outside. Eliminating the doors makes it nearly impossible for a driver to be ejected from the vehicle, where he or she could be hit by another car. It also means that the non-existent doors cannot become detached from the race cars, making them in to projectiles that could hit other cars or drivers. A lack of doors also means no door openings that could compromise the structural integrity of the vehicle.

The latest major change to come to NASCAR is the Next Gen car, a more modern version of the NASCAR race car first used for the 2022 NASCAR season. The chassis for the Next Gen NASCAR Cup Series cars will all be made by a single supplier, Technique Inc., located in Concord, North Carolina. The standardized chassis is made from steel tubing of various sizes, with the heaviest parts made into a roll cage that encloses and protects the driver. Lighter tubing is used on the front and rear clips, where it can crush and absorb energy during a crash or other impact. The rigid roll cage built into the chassis works with other parts of the NASCAR safety system like the driver's seat, safety belts, window net, fireproof suit, and helmet to protect the drivers.

Another interesting thing that NASCAR race cars do not have is automotive glass. Instead of using glass windshields, NASCAR race cars use windshields made of Lexan polycarbonate material, which is also used for the canopies of fighter jets. Because the Lexan is strong enough to resist impacts but soft enough not to shatter, it does a better job than glass when it comes to protecting the driver. A protective film is applied over the Lexan to preserve the driver's visibility. Funny enough, even though NASCAR windshields are not made of glass, NASCAR has windshield wipers.

One more thing that NASCAR race cars will no longer have, starting with the current Next Gen car, is sheet metal body panels. Instead, the bodies will be made of carbon-fiber-reinforced plastic. This offers added durability and flexibility during the inevitable NASCAR bumping and banging of cars during a race, as well as simplifying repairs after impacts with the walls that surround many of the tracks.

Two more rather ancient mechanical elements that also go away with the Next Gen car are recirculating-ball steering and solid rear axles. Recirculating-ball steering has largely given way to rack-and-pinion steering, which has become standard on nearly all road cars at this point, with the exception of old-tech stalwarts like the Jeep Gladiator and Wrangler. Solid rear axles will be replaced by a multi-link independent rear suspension on the Next Gen NASCAR race car, which permits the use of a special new NASCAR transmission on Cup race cars.