By almost any measure, Rusty Wallace had a tremendous NASCAR career: 36 Cup Series poles and 55 victories, the latter resting 11th on the all-time list. There were 17 top-10 points seasons in 22 tries, including 10 consecutive (1993-2002) for owners Raymond Beadle and Roger Penske. He won the 1989 championship with Beadle and crew chief Barry Dodson and went into the NASCAR Hall of Fame in 2013.
Impressive? Indeed… but perhaps his greatest contribution—unintentional, to be sure—came from spectacular crashes at Daytona Beach and Talladega in early 1993. There’s no telling how many drivers are alive today because of them.
It happened like this…
In the early 1990s—after upwards of 15 rollovers in that era—NASCAR had a problem: when turned around at speed, its cars and trucks often became airborne. Even at 3,600 pounds, they soared high enough to become entangled in grandstand fencing. Fans were injured when Bobby Allison got into the Talladega fencing in 1987 and Richard Petty went into the fencing at Daytona Beach a year later. Despite those frightening incidents, officials seemed unconcerned until Wallace’s two rollovers in 1993.
First came the season-opening Daytona 500. After contact with Derrike Cope and Michael Waltrip in the waning laps, Wallace spun and elevated, then sailed and rolled and tumbled eight time along the backstretch before landing upright. Footage shows his car clearly above the backstretch wall during one of its cartwheels. Penske’s No. 2 Pontiac was destroyed, but Wallace was uninjured.
Next, about three months later, came the Winston 500 at Talladega. A last-lap nudge from Dale Earnhardt in the trioval turned Wallace’s Pontiac around. Its tail lifted like a small plane taking flight, then began tumbling and rolling and bouncing a half-dozen times while shedding debris for almost 200 yards. Neither Wallace nor any fans were injured, but the unsettling question remained: what if he’d been in the high lane, closer to the grandstands? What if he’d gotten in the fencing as Allison had done six years earlier?
After more airborne crashes that season, officials reacted. When they suggested more engine restrictions to slow cars and keep them grounded, competitors howled. So, NASCAR president Bill France Jr. told Cup Series director Gary Nelson to gather experts and study ways of aerodynamically preventing rollovers. The effort turned an “oh, by the way” concern into a compelling one. France wanted answers, and he wanted them yesterday.
“NASCAR racing as we know it was threatened in the ‘70s and ‘80s because we were having so many rollover accidents,” Hall of Fame owner and aviation enthusiast Jack Roush said in 1994. “That’s because the production cars (on which race cars are roughly based) were getting aerodynamic for fuel economy. The tops of them were getting more rounded like the surface of airplane wings. That caused cars to generate lift when the air went over the top in a sideways or backward direction. We had to disrupt that air flow to keep the cars grounded.”
After the 1993 season—marked by Wallace’s two high-flying crashes and one by Johnny Benson at Michigan—Nelson, engineers from Roush Fenway Racing and former driver/crew chief/innovator Norman Negre (son of long-time racer Ed Negre) addressed the problem.
“NASCAR began working on it before anyone thought of roof flaps,” said Negre, whose lifetime contributions to racing are sorely underappreciated. (He’s worked at Stewart-Haas Racing since 2003). “It wasn’t Rusty’s wrecks alone, it was all the flips they were having. France wanted Gary to come up with a fix, to find out why that was happening. They asked people in the garage—the Wood brothers, I’m sure, and Harry Hyde and the Pettys—whether it might be the (low-hanging) fuel cell or the rear spoiler or the roof itself causing them to get off the ground.
“One idea was for me to build a rear deck that would come open (acting as an air brake) when cars got turned around. So, I built one (for the No. 30 Pontiac of Michael Waltrip) and reinforced it with heavy steel hinges and cable and wires so it would stay with the car if it popped up during a spin. But the people at the GM wind tunnel in Michigan didn’t want to test it because they thought the new piece might break loose and get into their fans. That ended that program right there.”
Undeterred, the group securely tethered the Chuck Rider-owned car to a long flatbed trailer and parked it behind France’s jet at the Darlington (S.C.) Airport. Engineers studied the car’s behavior when the jet’s engines were revved to 180 mph. They discovered that the velocity needed to lift the car depended on its angle on the trailer. The problem wasn’t so much that air was flowing under the car as it was air going over the car. That created a low-pressure vacuum that tried to lift it once it began to turn around.
“During one of the airport tests we noticed that the hood was trying to come up when the jet exhaust went over it,” Negre said. “The whole hood was bowing up big-time. We decided we needed to release the pressure up by the cowl, just in front of the windshield. We needed to “dirty” the air as it came from the back, over the roof, and over the hood. The cowl flaps on the hood came before the roof flaps. I don’t remember when it was, but the cowl flaps were mandatory the next race after that test.”
Nelson’s team eventually settled flaps near the back of the roof that come up when cars abruptly turn around at speed. The concept was partly inspired during lunch by the mechanical workings of the lid on a McDonald’s box. Later, Roush was tasked with designing and building the flaps. (The left one is square with the roof; the right is on a 45-degree angle to the roof). Basically, they “dirty” the air and reduce lift when cars are backward or headed that way. They’re flush on the body during normal conditions, then come up during a direction-changing incident. Shortly after testing, NASCAR mandated roof and hood flaps for every car on tracks a mile or longer. Dimensions varied at first, but have been 11-by-14 inches (hood) and 24-by-8 inches (roof) since 2014.
Driver-turned-TV-commentator Todd Bodine was among the first to benefit from the flaps after his No. 75 Ford was knocked around on the backstretch during the 1994 Daytona 500. He briefly spun around, then the car’s tail lifted before quickly settled back down.
“When it went off the ground and got real smooth, I started praying,” the youngest of the three racing Bodine brothers said at the time. “Then the roof and hood flaps went up, and the car sat right back down. I spun a few times, but didn’t flip, and that’s the important thing. It’s the single biggest thing NASCAR has done to improve our safety and I praise them for that. They worked exactly as they were supposed to. You can’t deny they are effective.”
Bodine recalls that competitors were skeptical when flaps were being discussed in 1993. “Racers are set in their ways with an old-school mentality,” he recently told Autoweek. “They don’t want any changes. When the flaps came out everybody said, ‘Shoot, they won’t work; what good can they do; they’re going to be a pain and make a lot of work for us.’ But NASCAR was right. After the first few times it was like, ‘Oh, man, I’m glad we have those on our cars.’ I think (NASCAR) knew there was a problem, but they wanted to do their research and test and study it before going forward. Rusty’s two crashes and some others made them speed up the whole process.”
Roush is anxious to explain that flaps were proposed by NASCAR itself. Basically, Nelson told Roush what France wanted, and Roush’s engineers took it from there. “We developed them so NASCAR would not slow the cars down more (with restrictor plates),” Roush said. “We didn’t have anything to do with the original design idea. That was all NASCAR. But our people made some springs and cables that kept the flaps from flying off the car until they were needed. It was the right system at the right time.”
Well, mostly. Even with flaps and other aerodynamic improvements, race cars continue to get airborne. (Other than Kyle Larson at Daytona Beach in 2013 and Ryan Newman at Daytona Beach in 2020, injuries to drivers and fans have been rare). In 2009, the day after Carl Edwards got into the Talladega fencing on the last lap of the Aaron’s 499, former Cup Series director John Darby addressed high-fliers.
He told the media (in so many words) that nothing on God’s green earth would keep fast cars running close together from occasionally hitting the proverbial fan. “If you could predict every spin of every car, the whole safety system would be very easy,” he said. “Although we can wind tunnel test and understand how the air will lift the cars, what you can’t predict and what you can’t test for is every single situation that cars may be involved in.”
So far, though, aero flaps have proved their worth more often than not.
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