Roof flaps help keep cars grounded
February 21, 2013, David Caraviello, NASCAR.com
Aric Almirola didn’t immediately feel his car decelerate. He didn’t hear the flaps deploy on the roof of his race car. All that he knew was that he was crashing -- and that his vehicle was staying on the ground.
“When you start wrecking and stuff, the last thing I was thinking about was my roof flaps opening,” the Richard Petty Motorsports driver said. “I couldn’t tell. But I think that’s one of the things that a lot of us drivers, we just take it for granted until after the wreck’s over and someone brings it to our attention that the roof flaps deployed and we didn’t get upside down. We appreciate it.”
A drafting accident during the Preseason Thunder test at Daytona International Speedway seemed the perfect recipe for sending a vehicle into the air -- cars at the front of the pack being turned sideways, others skidding through the infield grass, several spinning down onto the apron or jouncing up and down in the turf.
And yet they all remained on the ground, thanks in part to the larger, redesigned roof flaps on the new Sprint Cup Series cars, the latest weapon in the battle to prevent vehicles from going airborne at restrictor-plate tracks.
"I never felt like my car got light."
It’s a challenge NASCAR has faced for years, one mitigated but not completely eliminated by the use of restrictor plates at the sport’s largest facilities. The latest example was this past October, when Tony Stewart’s car rolled over the vehicle of Paul Menard in a chain-reaction accident on the final lap.
The crash in Daytona testing didn’t include nearly as many cars, and marked the first time the Generation-6 vehicles were involved in a drafting pileup. But the difference was still obvious, and seen in the form of giant roof flaps popping up like oversized dorsal fins.
“We were pleased with what we saw,” said Robin Pemberton, NASCAR’s vice president for competition.
In addition to being much larger than those used on the previous-generation vehicle, the new roof flaps also appear to deploy quicker, popping up before an out-of-control car reaches too severe an angle. They also contain what Pemberton calls “parachutes,” pieces of canvas stretching from one corner of the flap to an opposite corner of the housing, designed to further disturb air and raise the speed required for a car to go airborne.
The new flaps were mandated by the shapes of the new cars, which include a great deal more brand identity and are not uniform from one manufacturer to another. Daniel Honeycutt, director of vehicle engineering at NASCAR’s Research and Development Center, had been experimenting with improved roof flaps before the series phased out the previous car, Pemberton said.
When it came time for NASCAR and its manufacturer partners to design new vehicles to roll out in 2013, the series needed roof flaps in a different configuration to better wrap around the tops of the cars.
“We are better with this car than we were with the previous cars,” said Pemberton, an assertion that seemed on display in last week’s crash at Daytona.
The new flaps were tested in a wind tunnel owned by Dodge, which is large enough that vehicles inside can be turned 360 degrees, and which the carmaker continues to allow NASCAR to use even though it withdrew from the sport after last season. The two flaps on the hood are also larger, in keeping with the two on the roof. The fact that the Generation-6 cars are 150 pounds lighter than their predecessor did not factor into the change, Pemberton said.
Both RPM cars, those of Almirola and Marcos Ambrose, were caught up in the melee at Daytona, which involved about a dozen vehicles. Ambrose’s No. 9 Ford was the spark, slamming into the outside wall after being tapped from behind by Dale Earnhardt Jr., its flaps popping up as it turned down into traffic and began bouncing through the grass. Almirola’s No. 43 was trapped in the aftermath, turning sideways high on the backstretch, its roof flaps deploying as it began a long skid.
“I never felt like my car got light,” Almirola said. “I felt like my car was on the ground the entire time. Ran into plenty of stuff, and bounced off quite a few other cars, but never felt like my car was going to get off the ground.”
Immediately following the crash, all RPM competition director Sammy Johns thought about was the fact that he had two wrecked race cars. “Had we come through that, we’d have three Daytona cars (per team) sitting in our shop. Right now, we have two,” said Johns.
It wasn’t until later when he realized that none of the cars had gone airborne.
“I think you’re going to find a circumstance where you hit the wall hard enough or whatever, and you get enough force to pick the car up off the ground, you’re going to get air under it,” he said. “But the crash at Daytona, that couldn’t have happened in a better spot for a car to get airborne, and nobody did. Cars got in the wall and backward, and Marcos hit the wall pretty hard. There were a lot of circumstances there where cars would have gotten upside down in the past, and we didn’t see anybody get upside down.”
Johns said Ambrose told him that the No. 9 car felt like it was going up in the air at one point, but never did. The new flaps are “a lot bigger to help disturb the air even more to keep the cars grounded,” he said. For that, he credits the continuing work NASCAR does on the safety front.
The flaps are among several safety enhancements on the Gen-6 cars, which also include an additional roll bar in the windshield area, stronger windshields, and more secure window netting.
“You never know what to expect in racing,” Johns said. “We’ve seen cars hit walls we never thought they’d hit before. In every crash, I think there can be the element of the unexpected. You just don’t know. We’re going so fast, and so many different things can happen. I think the tracks and NASCAR and everybody are doing an extremely good job of being proactive nowadays, and not reactive. So as long as we can stay proactive on the safety side, I think we’ll continue to have a safe sport.”