Before Jonathan Tivel donned his crash helmet and climbed into his sleek white racing car, his father ceremoniously handed him a tiny index card for a last-minute review. The card explained how to achieve maximum speed, what to do if the car should swerve and, above all, how to avoid a crash.

Jonathan, age 10, was about to compete in the 1980 Metropolitan Washington Soap Box Derby, which yesterday transformed a stretch of Eastern Avenue near Varnum Street NE into a raceway and dozens of area youths into would-be Mario Andrettis.

Despite the sweltering sun that brought rivulets of perspiration to the faces of everyone attending, the race drew hundreds of mothers, fathers, grandparents and neighbors. At times it seems more of an event for the grown-ups than the young riders.

"Now remember what I'm telling you: don't turn the wheel too far when you feel yourself swerving, just try to keep the car straight," Carl Rice admonished his 13-year-old nephew Dirk Rice as the two made last-minute adjustments to Dirk's yellow fiber glass car.

The 11-member Voegtli family from Calvert County, Md., stationed a family member at various points from the starting line to the finish line so 11-year-old Melissa and her 12-year-old brother Joe would "know that they have support all the way down the line," their mother, Barbara Jo, said.

It was the fourth year a Voegtli had entered the race. Last race, Joe placed first in the junior competition for 10- to 12-year-olds. This year he participated in the senior race for 12- to 15-year-olds.

"It's a great thing for the kids. We happen to have a large family so it's even more fun," said their father, Bill Voegtli, who is in the construction business. "Kids learn to lose as well as to win, which is a part of living."

None of the Voegtlis placed this year, however. Joey Howell, 11, of Bowie, won first place in the junior race, and Gary Spangler, 11, won second place.

In the senior race, Hugh Flood, 14, of Rockville, came in first, and Eddie Scott, 12, of Bowie, placed second.

The first-place winners will compete in the National Soap Box Derby in Akron, Ohio, later this year.

Like many of the fathers involved in the race, Talbot Walls of Falls Church worked with his 14-year-old son Jerry on their entry for more than four months.

In the evenings and on weekends, the two would go down to their basement until the body of the car was pieced together, the brakes installed and the paint job finished, he said.

Walls said he spent about $400 on his son's car, the "Fantasy." Other participants said they spent between $100 and $400 to build the cars.

Rice, of the recreation department, complained that the high price of building the cars prevents many inner city youths from participating in the derby. Few local businesses, he said, have been willing to sponsor inner city youths in the race.

"Luckily we have a large family and we all pitiched in" for his nephew's car, he said.

David Bullis, 16, and his brother Rick, 15, of Millersville, Md., pooled their money from working after-school jobs at Burger King and cutting lawns to build their yellow and black-striped "Flying Coffin." It cost about $140 to build it, and Rick drove it in the senior race.

The "Flying Coffin" was eliminated early in the derby. But, said David Bullis, "I'm proud of it anyway -- whether it wins or loses or crashes."

Six girls participated in the derby this year. One was Lisa McFarland, of Fulton, Md., who said she got interested in the soap box derby because her brothers had participated in the races. How did she feel when she was gliding down the raceway in her car? "Scared, but happy."

What was she thinking about? "Winning."