ROANOKE TIMES

                         Roanoke Times
                 Copyright (c) 1995, Landmark Communications, Inc.

DATE: SUNDAY, June 12, 1994                   TAG: 9406140201
SECTION: SPORTS                    PAGE: C12   EDITION: METRO 
SOURCE: BY BOB ZELLER STAFF WRITER
DATELINE: POCONO, PA.                                LENGTH: Long


NASCAR LEARNS TO KEEP TIRES ON THE GROUND

KEEPING STOCK CARS from flipping proves a big challenge for NASCAR, but painstaking testing provides a solution - roof flaps - that seems to work. Last August, on a vacant runway at sleepy little Darlington County Airport in South Carolina, Winston Cup director Gary Nelson glumly contemplated what to do next after one of the most spectacular failures in the history of NASCAR safety experiments.

The goal was to develop a device that would help keep Winston Cup stock cars from flipping out of control after high-speed spinouts. After the unusual test, which involved the NASCAR jet, a flat-bed truck and a couple of stock cars, all Nelson had was two badly damaged cars.

The need to find a solution was urgent. A month earlier, Rusty Wallace had broken his left wrist after flipping more than a half-dozen times at the end of the Talladega race. And that was his second such crash of the 1993 season.

Stock cars have been flipping since the sport was invented, but the problem didn't become a major concern until 1987, when Bobby Allison's car spun at Talladega, lifted off the ground, tore out a huge section of the fence between the track and the grandstands and nearly caused a major catastrophe.

After Allison's crash, despite the increased use of carburetor restrictor plates to keep speeds down, crashes with flying cars seemed to happen more and more. One of the most terrifying crashes, involving the late Davey Allison, occurred in 1992 at We're pretty pleased with the progress of the roof flaps. Several hundred people and thousands of man-hours have gone into their design and development. Gary Nelson Winston Cup director Pocono. Until then, it had been thought that speeds at Pocono were not fast enough for a car to fly during a spin.

As every racing fan knows, NASCAR eventually developed the twin roof flaps that now are mandatory at all tracks a mile or longer. They apparently have solved the problem.

"We're pretty pleased with the progress of the roof flaps, . . ." Nelson said at a recent news conference. "Several hundred people and thousands of man-hours have gone into their design and development."

After a series of failed experiments, beginning in August and continuing through the fall, one would have been hard-pressed to predict that a solution would be found before the end of the 1993 season.

The initial proposal, suggested by General Motors racing engineer Don Taylor at a brainstorming session in Detroit on Feb. 25, 1993, was a pop-up trunk lid.

The concept was simple enough. When a car spun, air pressure popped up the trunk lid, which would disrupt the air flow across the top of the car to such an extent that it could not become airborne.

Tests had indicated that it was the air flow over the top of the car, not under it, that caused it to lift.

In a high-speed spin, "the car begins to basically act like a wing," Nelson said. "The airflow is increased over the top of the roof. That creates low pressure on top of the car, which overcomes the weight of the car and causes it to lift."

The first challenge, however, was how to test the deck lid. No wind tunnel would allow such a test, because if a part of the car broke loose, it likely would be blown all the way around the circular tunnel and into the huge wooden fan blades, damaging or destroying them.

NASCAR President Bill France came up with an idea. Use the NASCAR corporate jet to generate the wind, he said.

So, with cars loaned by Darrell Waltrip and Chuck Rider, who owns Michael Waltrip's Pontiacs, Nelson and others met at the small, remote airfield, where they could keep the test a secret.

With 3/16th-inch steel cables, they attached the cars to the back of a flat-bed truck 50 feet behind the NASCAR jet. Then they fired up the dual jet engines.

"We stood there at the airport that day and, man, you can't believe how strong that wind is," Nelson said. "The force of a 200 mile per hour wind is unbelievable.

"It blew the trunk lids right off the cars. It smashed the roofs down and damaged the back windows. We had the cars chained down on all four corners and when we hit it with the 200 mile per hour wind, it stretched the chains enough that all four tires came off the ground."

Obviously, it was time to return to the drawing board. The search for a solution became a cooperative effort that included NASCAR, General Motors and Ford engineers and a variety of race teams.

But the focus remained on a pop-up trunk lid. Several more tests were conducted at the Darlington airport, concluding on Oct. 13, 1993 with cars and new trunk lid ideas supplied by car owners Jack Roush, Rick Hendrick and Roger Penske.

Nothing worked. The lids kept getting blown off the cars or damaged, no matter how they were attached. During one test, they even damaged one of the engines on the NASCAR jet. "It was quite expensive to repair," Nelson said.

Spirits were low during lunch on that October day. But Nelson and GM engineer Gary Eaker started discussing the flap that NASCAR already had mandated for the cowl, which is the opening in front of the windshield.

"We started thinking, `What if we installed them on the roof?' " Nelson said. "We took some cardboard and some tape and started positioning where such a flap should be located. The idea sounded right, but we didn't quite know how we were going to fabricate such a piece.

"Jack Roush, who was present, said . . . his company would take the idea and produce it.

"By December, we were back at the airfield to give the roof flaps the acid test. Jack Roush had installed the prototype on one of his cars, and the flaps withstood the forces from the jet engines."

Although it was the holiday season, NASCAR ordered that the roof flaps be installed on Winston Cup and Grand National cars in time for Speedweeks at Daytona in February. For car owners, the task was burdensome. But it paid off.

"We couldn't ask a team to spin a car for us at 180-plus miles per hour, so our first on-track test came during Speedweeks at Daytona," Nelson said. "We feel like we got a true test when Chuck Bown spun in the 125 [one of the two qualifying races]. We watched it frame by frame. We watched the tires come off the ground. Then the flaps came up and the tires came back down. It was a vivid result."

Ritchie Petty also spun that day, and the results were the same.

"When Ritchie Petty's mother came up and gave me a big hug, that was all I needed," Nelson said. "And it was not only his mother, but his father and brothers and he himself. That was more satisfaction than I had felt in a long, long time."

Keywords:
AUTO RACING



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