NASCAR allegedly considering removing rear diffusers on Cup cars at short tracks to help racing product

NASCAR allegedly considering removing rear diffusers on Cup cars at short tracks to help racing product

Nearly halfway through its first season in use, NASCAR’s Next Gen Cup car has earned good reviews thanks to the quality of racing seen throughout the 2022 season. Week after week, the Next Gen car has made for exciting races at a variety of racetracks —  with one major exception.

Although the Next Gen car has greatly aided the racing product on intermediate speedways, it may have come at the expense of NASCAR’s short tracks. During a three-week stretch of short tracks in April, the Cup Series race at Richmond Raceway earned mixed reviews, and the following week’s race at Martinsville Speedway was widely panned for a lack of passing or any other on-track action. With several months to review those races before the next short track race, NASCAR is seemingly closing in on a solution to the malaise that plagued its early slate of short tracks.

Answering fan questions on his Stacking Pennies podcast, Cup Series driver Corey LaJoie revealed that NASCAR is looking at possibly removing the rear diffuser on the Next Gen car for short track races later this year. The change would be made in the interest of removing downforce from the cars, improving drivers’ ability to make passes and race in a way more aligned with what is expected from short tracks.

“If we keep the cars a little bit less stuck to the the race track — because now we have 25 percent more rubber on the ground due to wider wheels — I think if we took some downforce off to match, you’ll have some comers and goers and should make the short tracks a little bit more as we’re accustomed to seeing,” LaJoie said. “Nobody wants the short tracks to be more racy than this guy, and I know that NASCAR is certainly working on it.”

While Richmond ended up being an exciting race due to variable tire strategies playing out and creating a four-car battle for the win late in the race, it played out in a manner uncharacteristic of a standard short track race: long runs instead of tight confines, lots of contact and lots of action as a result.

At Martinsville, those issues were even worse. The aerodynamic effects of the Next Gen car created excessive turbulence (known to racers as “dirty air” in traffic), and a hard tire combined with unseasonably cold temperatures made for little tire wear and rubber buildup. This led to a race where passing, much less even getting close to the bumper of other cars, was extremely difficult. Two drivers combined to lead 397 of the race’s 403 laps, with the only passes for the lead occurring on pit road. Meanwhile, there were only four cautions, and only one of which was for an on-track accident.

Playing a part in this was the underbody of the Next Gen car and its rear diffuser, which creates a more even wake of air flowing from one car to another. While this has helped make for better racing on speedways that emphasize aerodynamics, its efficacy on short tracks has been called into question.

As noted by Kelly Crandall of RACER, there are two upcoming tests scheduled for Martinsville. The first is a Goodyear tire test on June 21-22 followed by an organizational test on August 23-24. Speaking to the media at Gateway, the Busch brothers backed up what had been said on LaJoie’s podcast about potentially removing the rear diffuser.

“I think the summer test session at Martinsville is where they’re gonna take the diffuser off to help see what it does for short track balance,” Kurt Busch said. “And then you have to execute a long run while you’re doing that, and it’s tough to do when there’s only the 10 cars or so that are there versus the 40 that start the race. We’ve just got to keep piling up information — and not necessarily looking at or collecting data — It’s let’s apply it, and let’s go for it.”

“I’ve been highly politicking to just take all the underbody off and let us go make a couple runs with that and see what we can figure out with that,” Kyle Busch said. “It would also save the team owners a heck of a lot of money if we just trashed all those components and went on without them from here on out. Wouldn’t hurt my feelings.”

Getting the racing product right at Martinsville is imperative for NASCAR. Not only is Martinsville the sport’s oldest track and one of its most popular, but it also serves as the penultimate race of the season and the elimination race in the playoffs that determines the Championship 4.