NASCAR Cup Series

Why are speeds surprisingly faster this season in Sprint Cup Series?

Published Mar. 12, 2015 2:45 p.m. ET

Jared Turner

When NASCAR announced its new 2015 rules package last September, many observers believed one of the biggest results would be a modest decline in speeds compared to 2014.

A reduction of horsepower on Sprint Cup Series cars from 850 to 725, combined with a lowering of the rear spoiler from eight to six inches, figured to make the cars both slower at the end of the straightaways and harder to drive in the corners.

But in two races with the new rules package (the 2014 package was used at Daytona), speeds have not dropped off. They've actually gone up.

The question is why.

It turns out there are likely multiple factors involved -- ranging from weather conditions to the type of tire Goodyear brings to the track on a given weekend. But there is another, more static, explanation for why the pole speeds at both Atlanta Motor Speedway and Las Vegas Motor Speedway the past two weekends actually eclipsed the pole speeds from these same tracks in 2014.

"Our entry speed into the corner is slower because we have less horsepower, and because our entry speed is slower, it allows us to run faster across the center of the corner and we still have a relatively large amount of downforce on these cars," said driver Aric Almirola. "Like in qualifying at Atlanta and Vegas, you hear all the drivers talk about it -- we're really, really close to wide open, if not, some of the guys are wide open, and we're just going extremely fast across the middle of the corner, and the only way to really make us go any slower in the middle of the corner is to make us go faster at the end of the straightaway. So we have to slow down, or take a bunch of downforce off the car.

"Obviously going fast at the end of the straightaways is not something that's in everybody's best interest," he said. "I don't think NASCAR or anybody else wants to see us running 230 miles per hour at the end of the straightaway."

Joey Logano's pole speed of 194.683 mph at Atlanta two weekends ago was more than four miles per hour faster than Kevin Harvick's pole lap of 190.398 at AMS last Labor Day weekend.

Last weekend at Las Vegas, Jeff Gordon recorded a fast qualifying lap of 194.679 mph -- still quite a bit faster than Logano's pole lap of 193.278 from a year earlier.

While the difference at Atlanta can be partly attributed to cool late February temperatures versus the relative warmth of early September, differences in temperature aren't solely to blame for this year's faster speeds.

"We had speculated we would see end-of-straightaway speeds drop by 2 to 3 mph, and that's about what we saw," said Gene Stefanyshyn, NASCAR senior vice president of innovation and racing development. "We did speculate that the corner speeds could go up a bit because we took some mass out of the car. We did calculate the speeds would go down because we took downforce down, but the other element in there is you bring a tire with more grip and the corner speeds go up, and that's one of the issues: A softer tire gives more grip where you'll get more tire falloff, but then what happens is the corner speed goes up, so this is the Rubik's Cube that is trying to be solved. How do you get softer tires to give more tire falloff without driving the corner speed way up? That's one of our dilemmas."

Almirola, for one, hasn't been surprised to see speeds rise this season, even with the changes in downforce and horsepower.

"Everything's just evolving. You see it year after year after year -- we just keep getting faster and faster and faster, and it's because there's a lot of smart people in that garage area that work on these race cars," the Richard Petty Motorsports driver said. "So it's a tough challenge for NASCAR to try and slow them down because that's what those guys get paid to do. There's a lot of people in that garage that get paid a lot of money to figure out ways to make our race cars go faster, and they've been able to do it time and time again no matter what the rule changes are."

Keith Rodden, the crew chief on Kasey Kahne's No. 5 Hendrick Motorsports Chevrolet, likewise didn't expect to see the drop-off in speeds this year that others initially did.

"When you go 220 into the corner, the front end pushes, so you have to brake and you have to slow down a lot more," he said. "Well, if now you're going 200 into the corner, you don't have to quite slow down as much. So you don't overrun the fronts or make the front tires slide on entry and lose grip, so now you're able to kind of stay in there and keep the car turning a little bit and go. I think some of it's (also) the track condition and some of it's the tires."

No matter the cause of the increase, NASCAR simply wants to make sure the speeds don't rise to a level it deems unsafe.

"Obviously safety's a very big concern," Stefanyshyn said. "We look at the ultimate speeds and some of the (testing) work we did last year in Michigan with a lot of the aero work and aerodynamic devices off the car. We were approaching 226 mph, which for us is at the threshold where we begin to feel uncomfortable. So we have to manage the speed and the safety as part of this whole package."