ART WILLIAMS glances nervously between his stopwatch and Turn 10, at the far end of the straightaway. Kicking up great clouds of red sand, a tight pack of racers careen around the curve, drop into fifth and accelerate into lap two. As expected, the yellow Porsche has maneuvered into first position, only two minutes after the pace car left the track. Close behind, a red-white-and-blue Datsun pulls inside for the next turn while the loudspeakers announce, "P.L. Newman now in second." Of course, only the officials call him "P.L."; to everyone else he's just plain "Paul."

Art looks back at the little numbers flipping by: 1 minute, 40 seconds. His assistant Dave checks his own watch: 1:50. Next to him Shawn clicks off his timer: 2:00. The three mechanics glance at each other and turn again toward the distant bend. "Where's Bill?" Art whispers. Six, eight, a dozen racers streak past and still no green-and-white Datsun with the 7-Eleven logo. Still no Bill Thrasher. By not it's obvious something has happened. Even handicapped as he was by the wrong suspension, the two-mile course shouldn't have taken anymore than a minute and a half.

"Where's Bill?" Art whispers.

EARLIER THAT MORNING. The atmosphere is not so tense as the crew prepares for the final race at Summit Point, West Virginia, by replacing a broken spring. Dave and Shawn struggle to clamp down the overgrown Slinky while Bill watches quietly from his cluttered van. Lean and hunger-looking, with curly blond hair and watery blue eyes, the 40-year-old salesman peers out through his aviator sunglasses and lights up another Malboro as he weighs the question he's just been asked.

"'Why? Why do I race?' I guess I do it for selfish reasons - I do it for myself. I enjoy winning. I enjoy the spectators. These Datsun drivers out there feel like they're right behind the wheel with you. They lean into the turns, left and right. Also I do it for the muscular dystrophy kids. They're never gonna drive, so they really look at this as their car, and they want it to win."

Under each door Bill has painted "Race Against Muscular Dystrophy." He and his car raise money almost every weekend at local shopping centers. The fund drive is his favorite topic: "I was down in Atlanta once, and didn't even win 'cause some little thing busted. But after the race a little kid in a wheelchair comes up and hands me a picture he'd drawn of my car. I really appreciated that. Friend of mine wrote an article about the whole thing. Wanna see it?"

Rummaging about for the handwritten manuscript, he returns to his original topic. "When 'Man of La Mancha' came out, I could really relate to Don Quixote. When you're on the track, every turn is a conquest. You're right out there with the dragons and windmills. Or sometimes it's like a silent ballet and you have to keep things dancing."

Lost in the poetry of the moment, Bill waxes eloquent in answer to "why." But "how" is another question: How does a racer pay for it all? A name like Paul Newman will draw big money from national sponsors, enough to keep his two Datsuns and a Ferrari on the track. Others are not so fortunate. The 200 or so active members of the Washington region Sports Car Club of America usually depend on their regular jobs. Amateur racing offers no cash prizes.

In a later, more relistic mood, Bill details the expense: "A car like mine cost $5,300 in 1974, fully equipped. Today that would run $10,000. Figure another $10,000 to strip it down, buy new equipment, alter the engine and put it back together into a racing machine. After that, it'll cost $1,500 a season to keep it in shape if you're mechanically inclined, maybe $5,000 a year if you aren't."

Not quite as cheap as jogging.

Bill is luckier that most of his fellow racers. His charitable efforts impressed 7-Eleven enough to offer him a $3,000 sponsorship.But such corporate support is difficult, often impossible, for the average racer to obtain.

"I talked with several people before 7-Eleven and nobody would even give me the time of day. Finally one company indicated my $7,000 request sounded reasonable. So I said, 'Do you want me to send you purchase orders or will you just write a check?' The reply was, 'We said it sounded reasonable, we didn't say we were going to give you any money.'"

The Playboy Corporation turned down his request as well: "96,000 for a modified 280-Z.

Of course Bill's introduction into racing was somewhat more humble than dropping five-digit suggestions to Hugh Hefner.

"Back in 1954 my brother built his first drag racer. We called it 'The Green Hornet.' I raced it for a couple of years until I was transfered to Asia with the Navy Seals." Home in 1959 long enough to buy a new Chevy, he soon shipped out to the Mediterranean. A short time later Bill returned to Bethesda Naval Hospital after a fire on board the USS Lake Champlain "melted a wet suit to my body. I've been uncomfortable around the heat ever since . . . By the time I got back, my family had converted the Chevy into a dragster. I drove that until 1964, when I bought a Corvette and discovered road racing."

Back at the van, Art returns from a scouting mission and follows his boss to the car.

"You ought to see Newman's Ferrari!" he bellows. "That thing's runnin' like a scalded dog!" Assisting Bill as he bleeds the brakes, Art continues with his narrative.

"I was standing over there watching him, and P.L. looks up at me and asks would I do another Datsun driver a favor? 'Sure,' I says and he says, 'Help me with my strap.'" From beneath the right front wheel Bill interrupts his mechanic's grin with a muffled "Pump it!," a command he continues to interject for the next ten minutes.

Stopping by to watch the operation, a wilted friend offers a lame joke about the heat. "Oh, I don't know," Bill adds with a grunt as he snaps a bolt. "It was pretty darn cold in my bedroom last night." His heads pops up long enough to wink at Art and resubmerge, setting off a round of knowing laughter.

Half an hour later, we pick our way carefully through a metropolis of Winnebagos, trailers, pup tents and cars. Girls in halters and guys without shirts wrestle with curiously shaped machines through the dusty gravel paths. Our objective is a cold drink. Meanwhile, Bill reflects on the conflicts spawned by his obsession with racing. He interprets his earlier cryptic remark: "My wife and folks were up yesterday, trying to convince me to give up racing. It didn't help matters any that my next-door neighbor was killed here at the last race. Also, the money we spend upsets my wife. This weekend alone cost $300 of our own cash."

Bill neglects to mention the cost in time: 20 hours a week on tinkering with his car and 20 on displaying it for the fund drive. Hesitating for a moment, he coughs and continues: "My folks asked me what I would do if Heather left. I said I guessed I'd just keep on racing. 'You mean you'd rather race than be married?' they said. 'No, now you're putting words in my mouth,' I told them." Heather and their daughter, Jennifer, both stayed home today.

As we round a cluster of Port-o-Cans, an immense German shepherd makes a lunge for us, only to be choked back into decorum by his chain-link leash. "My wife's ancestors donated land for the first DAR chapter, helped establish the U.N. and were from snooty society in Cincinnati. They weren't hard-core blacksmithing people like myself. She's a tall, slender, beautiful woman and hated every minute she was out working on my car. Now she's leading a revolt like that Greek lady." The allusion is to Lysistrata, who ended the Second Peloponnesian War by having all the Greek wives deny their husbands sexual favors while the fighting lasted.

The concession stand is closed. On the long trek back, Bill allows the uncomfortable subject of family pressure to drop from the conversation.

Entering the pit area, we pause to watch a race. One teenager is ecstatic over the lead car's untimely collision with a wall: "My dream did come true. Pete wiped out!" Turning her attention to the new leader, she shouts with equal gusto, "Flip it, Tony, flip it!" Instead, those great wheels of justice come full circle - her own car is nowhere to be seen. "Dad? Where are you, Dad?" Ten minutes later the speaker announce the answer: Number 22 is out with a broken axle. She flings one last, defiant "Creep!" at Tony, then turns and stalks off.

We pass a cluster of what appear to be burned-out wrecks. Our guide nods and solemnly explains: "Bill Scott uses these bumper cars in his chauffeur-training school. You know - to prepare them in case of terrorist attack." Nearby lies another twisted heap of metal, formerly a Spitfire. "Could have been an easy second," moans the owner, "an easy second." Bill grins, sets off again and offers a word of advice: "The race ain't over until the checkered flag drops."

Back at camp, Bill dons the accouterments of his hobby, quickly checks his vehicle and climbs in behind the wheel. Securiting the seat harness and slamming the door, Art adds with a wink: "Like we told you, Bill, just keep the shiny side up." Before he fires his engine, Bill is again asked "Why?" - this time in light of the danger and the cost and the objections of his family. Sometime later he provides a partial answer through the words of world champion driver Niki Lauda:

"Once in your lifetime, you have got that decision: Do you want to practice this profession? Do you want it and all that it involves? If you ask yourself that question, and if you answer it in all honesty with 'yes,' that means you have beaten the problem.

Then you can't be afraid any more, because if you are, you must have answered that question with a lie."

AT THREE MINUTES, Bill still hasn't shown. The pit crew watches-bind his hood together with a coat hanger and sprints on out of the pit.He swerves to avoid a rapidly approaching Lotus Elan, "Quasimodo" inscribed across its front and "Electric Raspberry Racing Machine" across its back. Finally, in the distance appears the long-awaited Datsun, slowly rolling toward the safety area. As Bill brakes to a stop, Art leaps to inspect the smashed fiberglass airdam. "Tape it!" yells the driver, "Tear it!" hears the mechanic over the noise, so rip - off goes the airdam. Bill shrugs, throws it into first, and limps back into the race.

Half an hour later, the Trasher group heads for the trailer while the Porsche takes its victory lap. Bill slowly removes his helmet, leaning against the car while the adrenalin subsides. "Something broke. Something busted in the rear end. The front went right up in the air and into the wall down by Turn 5. It never ran right after that."

Shawn is passing out a round of Michelob while Bill continues with the damage report. "Also cracked the rear fender in that cluster of cars on the first turn. Me and a Datsun collided." Art shakes his head. "Doesn't matter, my man, you finished the race, that's all that counts. And you didn't finish last, either." Dave nods agreement: "You're still my main man." Shawn looks up and grins: "Have another Mick."