Simplified Diffuser

NASCAR News: Diffuser & other updates for short tracks & RCs

NASCAR Cup Series cars will run a simplified diffuser at most tracks measuring one-mile or shorter, as well as all road courses. (Note: Bristol and Dover excluded.) This update comes following driver feedback from the test at Phoenix Raceway in early December.

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

The simplified diffuser will not be used at the Los Angeles Memorial Coliseum.

Diffuser Changes
Diffuser Changes

Eric Jacuzzi, NASCAR Vice President, Vehicle Performance: “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.

With the revised diffuser, 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.” NASCAR