NASCAR updates package for short tracks, road courses for 2024 season

The NASCAR Cup Series will run a simplified diffuser at a majority of the tracks 1-mile or less in length, as well as all road courses, the sanctioning body announced Wednesday.

The change is part of NASCAR's efforts to improve racing at short tracks and road courses.

The change impacts all tracks 1 mile in length or shorter except Bristol and Dover.

NASCAR also stated that this new diffuser will not be used at next month's Busch Light Clash at the Los Angeles Memorial Coliseum.

The diffuser channels air underneath the car.

The change comes after driver feedback from a test in December at Phoenix Raceway. Ryan Blaney, Chris Buescher, Christopher Bell, Erik Jones, Corey LaJoie and Kyle Larson participated in the test.

Eric Jacuzzi, NASCAR Vice President, Vehicle Performance said in a statement: "At the test, we noticed an improvement in traffic. The car did not lose rear downforce when it yawed, which is an issue we fight with the current car.

"The drivers would be able to slide around more on the short tracks and really have to be less careful about putting power down. We felt that would be a benefit, and that was the big takeaway from the driver feedback.

"At the test, they felt they could really tell that it was more forgiving. They felt they could slide the car."

The details of the components update:

  • 2023 short track/road course splitter stuffers

  • No engine panel strakes

  • 3-inch spoiler

  • Simplified Diffuser

  • Simplified Diffuser Strakes

NASCAR provided renderings of the diffuser used last year at most short tracks and all road courses vs. what will be used at those events this season.

2024 NASCAR Short Track diffusers.png
2024 NASCAR Short Track diffusers.png