This weekend at Phoenix, NASCAR will debut a brand new aerodynamic rules package to be used on short tracks and road courses for 2024. There are three different rules packages that the NASCAR Cup Series uses throughout the season, but, what makes each of them unique? We dig into that today.
There is a common theme throughout these rules packages that fans will notice. Generally speaking, the shorter the race track, the lower the downforce on the race car.
The reason for this is that the big race tracks require a certain level of grip to allow the cars to keep control at high speeds. At superspeedways, the high downforce is used to slow the car down by creating drag. On short tracks, the speeds are slower, so, less downforce creates less grip for the cars which should allow for more mistakes and generally better racing.
Less downforce also means the car is less reliant on aerodynamics. Cars heavily reliant on aerodynamics are more susceptible to “dirty air” in the corners, which is created by the car in front pushing through the air. This turbulent air causes the following car to lose grip in the corners.
There are a few exceptions to this rule due to some tracks producing higher speeds than others. We will get into those specifically when we talk about the rules packages, but, the idea of NASCAR using more downforce at higher speeds still remains pretty well in-tact
Tracks Used at: Phoenix, COTA, Richmond, Martinsville, North Wilkesboro, Sonoma, Iowa, New Hampshire, Chicago, Watkins Glen, Charlotte Roval
Breakdown: This track is used on some of the slowest tracks on the schedule, meaning low-banked short tracks and all road courses. It’s intended to have very low downforce so that the cars are tougher to drive at slow speeds. The highlights of this package include a standard 670 horsepower engine alongside a smaller real diffuser with fewer vertical strakes and a 3-inch rear spoiler. This was changed from 2023 which had a larger rear diffuser and a 2-inch spoiler. These changes are aimed at reducing both downforce and “dirty air” behind a car.
Tracks Used at: Las Vegas, Bristol, Texas, Dover, Kansas, Darlington, Charlotte, Gateway, Nashville, Pocono, Indianapolis, Michigan, Homestead-Miami
Breakdown: This package is the most heavily utilized on the circuit, and it is aimed as a happy medium between downforce and speed. It includes a standard diffuser with a standard 670 horsepower engine. The one unique aspect of the package is a 4-inch rear spoiler. This package is used at all intermediate tracks plus the 1/2 mile Bristol Motor Speedway and the 1.0 mile Dover Motor Speedway. These two tracks use the package because their high banks create higher speeds and the need for more downforce.
Tracks Used At: Daytona, Talladega, and Atlanta
Breakdown: This rules package is specifically designed to curb the speeds at superspeedways like Daytona, Talladega, and Atlanta. The high drag, high downforce nature of the package creates the large packs of cars we see at these types of tracks. The package includes a standard rear diffuser, but, the engine is restricted to only 510 horsepower. The spoiler is also a whopping 7 inches high, nearly twice as high as the speedway package. While tracks like Pocono and Indianapolis are both around the same length as Daytona and Talladega, those first two tracks do not this package because the low banking reduces the speeds. Atlanta is a 1.5 mile race track, but its high banks create a superspeedway-style race, necessitating this package.
For any race coming up, the rules package plays a large role in what type of race that fans will see. Which one wil produce the best racing in 2024?
