NASCAR’s latest attempt to improve the racing product on short tracks and road courses is a simplified rear diffuser package with a spoiler adjustment to offset those changes.
The following rules will apply to all road courses and short tracks with the exception of Bristol and Dover. It will also not be used in the non-points Clash at the Los Angeles Memorial Coliseum.
• 2023 short track/road course splitter stuffers
• No engine panel strakes
• 3-inch spoiler
• Simplified Diffuser
• Simplified Diffuser Strakes
The biggest visible change will be adding an inch of rear spoiler to offset the underbody changes. In theory, this could help increase tire wear as well.
These changes were largely the result of the two-day test at Phoenix Raceway in early December. In real time, those tests did not produce enthusiasm from the participating drivers but they did feel Goodyear brought a more aggressive tire compound. The second day turned into a muffler test.
“At the test, we noticed an improvement in traffic,” said NASCAR vice president of vehicle performance, Eric Jacuzzi. “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.”
Those changes have been visualized below. The new package is on the left and the one it replaces is on the right.
Matt Weaver is a Motorsports Insider for Sportsnaut. Follow him on Twitter.