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NASCAR rules package for 2021

While a completely new car with new rules packages will debut in 2022, the current 2021 season features a number of changes to the various engine and aero packages that will be used.

Here’s a breakdown of those changes:


There will be three different types of engine packages used across 37 races (includes the non-points All-Star Race at Texas Motor Speedway):

* The higher horsepower Taper750 — which signifies 750 horsepower under the hood — will be used in 20 races at 15 tracks: Bristol Motor Speedway (both oval and dirt), Charlotte Motor Speedway Roval, Circuit of The Americas, Darlington Raceway, Daytona Road Course, Dover International Speedway, Indianapolis Road Course, Martinsville Speedway, Nashville Superspeedway, New Hampshire Motor Speedway, Phoenix Raceway, Richmond Raceway, Road America, Sonoma Raceway and Watkins Glen International.

* The lower horsepower Taper550 — which stands for 550 horsepower — will be used in 13 races at eight tracks (including the All-Star Race at Texas): Atlanta Motor Speedway, Charlotte Motor Speedway, Homestead-Miami Speedway, Kansas Speedway, Las Vegas Motor Speedway, Michigan International Speedway, Pocono Raceway and Texas Motor Speedway.

* The superspeedway package — will be used in the four combined races at Daytona International Speedway and Talladega Superspeedway. The package will not be used on the Daytona road course (that will be the Taper750).

Several changes in the superspeedway package actually went into effect last season following the crash involving Ryan Newman in the 2020 season-opening Daytona 500.

Those changes, which have carried over into this season, include:

* Reduction in horsepower via tapered spacers

* Elimination of air ducts

* A reduction in throttle body from 59/64 inches to 57/64 inches

* A lower main roll bar supporting bar, an intrusion plate and upper main roll bar support bar

* Updated roll bar padding

* Oil reservoir tank or overflow expansion tank must contain a check valve

* Slip tape must be applied along the entire length of the lower rearward facing surfaces of the rear bumper cover and extension

Two tracks will use two different types of engine packages this season:

* Charlotte will see the Taper550 used for the Coca-Cola 600 and the Taper750 for the fall road course race.

* Daytona used the superspeedway package for the season-opening Daytona 500 (and will also use it for the late summer regular season finale), while the Taper750 package was used for the road course race that occurred the following week this past February.

As for other new rules, teams must compete in a minimum of 16 points events with a short block sealed engine, up from the previous minimum of 13. In addition, teams are also restricted to 150 Restricted CFD (computational fluid dynamics) runs per calendar month.


There are also changes in aero packages that will be used throughout the 2021 season:

* A significantly smaller rear spoiler, which shrinks from an 8-inch height to 2.75 inches.

* The front splitter’s overhang measures a quarter-inch (down from 2 inches), with approximately 2-inch wings (reduced from 10.5 inches).

* Alterations to the radiator pan, removing its vertical fencing in an effort to reduce front-end downforce. The dimensions of the pan remain the same.

NASCAR will use three different aero packages:

* The NA18D package will be used at nine tracks: Atlanta, Charlotte (speedway course), Homestead, Kansas, Las Vegas, Michigan, Pocono, Texas (regular season race plus All-Star Race).

* The ST/RC short track/road course package will be used at 13 tracks: Bristol, Charlotte road course, Circuit of the Americas, Darlington, Daytona road course, Dover, Indianapolis road course, New Hampshire, Martinsville, Nashville, Phoenix, Richmond, Road America, Sonoma and Watkins Glen.

* And, of course, the standard superspeedway aero package will be run at the four combined races at Talladega and Daytona.

“We constantly review the race packages to try to put on the best possible racing for our fans,” said John Probst, NASCAR’s senior vice president, innovation and racing development