It’s become a theme of the past three years but the new Cup Series car continues to be an offensive car, where the previous generation platform, including the Xfinity Series car, is an offensive car.
In other words, a significant advantage goes to the leader in the NextGen car because he can air block his pursuer with the advantage of clean air. It forces the second-place car to get aero tight and push up the track.
In the previous generation car, and the Xfinity Series car, the second-place car can get the leading car loose without even making contact, in the efforts to create a pass. That was on full display last weekend at Indianapolis.
In the Saturday race, the lead changed hands twice and Riley Herbst was able to complete a last lap pass by getting Aric Almirola aero loose.
Denny Hamlin, speaking on his Actions Detrimental podcast, says he was watching from his motor home and was reminded at how much the current Cup car fails do that and how NASCAR also failed to deliver a car that was better in dirty air.
“We’re in such a weird spot where the leader has such an advantage on that track because he’s got the clean air,” Hamlin said. “You can run so much faster when you have the clean air. And we all know these Next Gen cars are terrible in traffic. They’re the worst cars in NASCAR in traffic. So when we designed them we designed a car that is worse than it’s ever been in traffic.”
The NextGen car generates a tremendous amount of turbulence for a trailing car. It’s largely fine if a track is wide enough to create a second groove for a driver to find clean air to complete a pass but this car is also wider than those that came before it.
It also is the byproduct of a rules package NASCAR used for three years before the advent of the NextGen, which served as a testing ground for this new car, but was extremely bogged down by dirty air. Hamlin says he sough assurance from NASCAR that they found a solution.
They did not.
“I asked them three times, three times I asked John Probst before this car came out, ‘Are you sure it’s right? Because you haven’t put it around any other cars during these preseason tests,’” Hamlin said. “Then finally in December before they launched the car they put it on track with another car and they see that it’s, ‘Oh shit, we’ve got a problem.’ Well no kidding. You had two years to figure this out. God, it’s frustrating as hell.”
The new Cup car features wider tires and makes more grip. It has less horsepower from a weight standpoint. It has slits in the windshiled to keep drivers cool but that also creates additional drag. That combined with the underbody and wider body also creates a wider turbulence.
NASCAR attempted to utilize a 510 horsepower rules package with this car too during the first preseason test at Charlotte Motor Speedway. It was so bad in dirty air that teams forced a second test and NASCAR relented with a horsepower increase to make marginal gains with the car in turbulence.
The Xfinity cars are lighter and feel like they have more power as a result. They also are not as planted in the rear so it makes it easier to move the car with air.
“That is the big difference between XFINITY and Cup, is that Cup, the closer you get to them, your car takes off,” Hamlin said. “You lose all downforce. It’s done. The closer you get to the car in front of you in XFINITY, and what we saw Riley Herbst and many others do is that as soon as you get close to the rear of the car, they start losing rear downforce, and then they get off the bottom and they shuck them.
“And that’s what we used to do with the Gen 4 car and 5 car, is that we could always get the guy in front of us loose. Now you can’t do that because they are not making any over-body aerodynamics, and it’s all under body. So you’re not able to take air off their spoiler, because there’s not hardly any air going on the spoiler in the first place. We got a physics problem. I wish they would just let us come up with our own package for that track just one time, and let us decide what we’re gonna run.”
