MANASSAS - Lance McDermott is spinning around 15 feet in the air like a top on steroids. His hands twitch at his sides. His eyes bounce and dart. He murmurs inaudible partial sentences to himself.

Like every Saturday night, Lance is experiencing the longest day of his life.

"This is the hard part," he bellows over the piercing scream of engines wailing past, still twirling on top of a massive white trailer at Old Dominion Speedway.

Tonight, Lance is working especially hard. For the first time in a few years, both of his daughters -- Amanda, 18, and Danielle, 16 -- are racing in 3,200-pound machines at the same time. That means he has to follow the every swerve and swivel of two cars running on opposite sides of the field.

"Longest day of my life," he says for the second time, still risking dizziness.

Amanda and Danielle have been racing at Old Dominion since they were 5 years old. They are novelties at the legendary track for two distinct reasons: First, they are young competitors, but damn good drivers. And secondly, they are females.

"They're my heroes," says Jennifer Lubkowski, an honorary McDermott crewmember, and Danielle's best friend. "They're amazing. What they do is just amazing."

No matter how amazing Amanda and Danielle are in their cars -- Amanda is third in points in the veteran-dominated Grand Stock division, and Danielle has arguably as much natural talent as any driver at the track -- Lance still drives himself crazy with worry.

"I probably get more butterflies at the start of their races than they do," Lance says of his only children. "That's just the fear of something. I'm not sure what, but just the fear of something."

* * *

Lance McDermott almost lost his legs in a horrific motorcycle accident when he was 18, so when Amanda showed interest in motocross as a 5-year-old, he quickly ushered her toward go-carts.

The sisters say they were always intrigued by speed, the rush of driving fast with the wind blasting in their faces. They tried basketball and volleyball and soccer and tennis, but nothing excited them like climbing into a racecar and slamming down on the pedal.

Plus, they were good. Amanda and Danielle both won track championships at Old Dominion, collecting enough trophies to clutter their sprawling house in Broad Run with hordes of bronzed figurines.

"They're certainly very competitive young girls," says Old Dominion track manager Haynes Dominick. "They're showing some real talent. It gets us a lot of attention, both locally and nationally, to have two young girls who are not only competing with the guys, but are competing very handily."

The McDermotts started with an old go-cart and a slab of concrete behind the family's house where Lance and the girls tinkered with the tiny car. That grassroots enterprise has blossomed into a full-fledged push for professional stardom: Three years ago, Lance built a 2,500-square-foot garage adjacent to the house that's now filled with massive tool boxes, assorted cans of paint and discarded car parts -- "Everything you need to make a car go around a racetrack," Amanda says.

Once the trophies started piling up, outsiders took notice, helping the sisters garner elite sponsorship; Amanda's chief backer is Mountain Dew, while Danielle's primary sponsor is Sobe. Their cars -- sleek, attractive and innovative -- are two of the most recognizable at Old Dominion.

"They're great out here," says 35-year-old Les Miranda, the top driver in the Grand Stock division. "I think they were born with a steering wheel in their hands."

* * *

Danielle, whose nickname is "Pea Pod", always preferred playing in dirt piles behind the McDermott house when she was growing up, and didn't mind getting blobs of grease on her face when working on a car with her father. As for her garb, you'd always find her in a dusty T-shirt and tattered blue jeans.

Amanda, meanwhile, liked pink nail polish and bright skirts. Her golden hair was always immaculate, and she seldom left the house without a matching ensemble.

Both sisters share the same beauty pageant good looks: straight, even-features, toothy smiles, slim figures and long manes of shimmering blonde hair. That's where their similarities end.

Amanda is quiet and cerebral; Danielle is loud and boisterous. Amanda stands largely alone before races, clearing her head; Danielle spontaneously bursts into dance, and belches loudly whenever possible.

"They're just two totally different personalities," Lance says. "Sometimes I can't believe they came from the same house."

Those differences are never as obvious as when they're on the track. Amanda is patient and persistent, and seldom takes serious chances. Danielle, meanwhile, jumps at the prospect of them -- "Fearless," says crew chief Talbot Watts. "She is fearless and races with a natural aggression."

The sisters border on opposites when racing: Lance often urges Amanda to be more aggressive, yet routinely has to coax Danielle to dial her aggression down. Moreover, Amanda has earned widespread respect at the track for her clean, courteous racing, while Danielle admits to being reckless at times -- "She doesn't really wait for a big hole," Amanda says. "If she thinks she can squeeze by, she's going to try."

"Amanda is a learner; she learns very well and she has a good feel for racing," Lance says. "I'd say Pea Pod probably has more natural talent than Amanda. Pea Pod has a lot of natural instincts. She can drive very, very well by the seat of her pants.

"It's kind of totally opposite for us to work with them."

Both sisters, however, deal with breaking into the male-dominated sport. When they first moved into the top divisions at Old Dominion, there was some resistance -- "The racers get ribbed if they get beat by a girl. They'll tell you," Lance says.

There were turned backs. There were sneers. There were rude comments. There was friction.

That iciness began dissipating once Amanda and Danielle started piling up the wins -- combined, they've taken about 30 checkered flags in 12 years.

"I think when I first started it was kind of a cold shoulder thing," Amanda says. "But I think the more I'm there, the more respect I get because they see that I'm a capable driver, and that I drive everybody clean. Now it seems like everybody's glad I'm there."

Everybody seems to be. During pre-race announcements Saturday night, the obvious fan favorites are Amanda and Danielle, who elicit a raucous ovation from the dense packs of fans in the bleachers when their names are called. Simultaneously, many crewmembers in the various pits along the infield hoot and whistle at the blonde-topped duo.

"They're good for this sport," says Miranda, "and my youngest daughter loves them. She wants to be just like them. I think it's great."

* * *

Before Saturday's race, the McDermott pit is overflowing with various crewmembers. Jim McDermott, the girls' uncle, is under the rear end of Amanda's car, banging away with a soft mallet. Lance bounces between both cars, checking tire pressure and measuring each vehicle intricately. Talbot Watts drifts about, chain-smoking Winston's and wiping sweat from his forehead.

"I guess you could say I'm like a big brother to them," Watts, 35, says between drags. "They trust me like a big brother."

Watts, like Lance, is saddled with devoting equal time and energy to Amanda and Danielle. It can be difficult at times, he says. Amanda is the top priority of the team by way of seniority. At the same time, she is the guinea pig of sorts, the first to try out new cars and equipment.

In turn, Danielle gets Amanda's hand-me-downs; she competes in Amanda's old cars and with Amanda's old parts. This sometimes bothers the younger McDermott -- even if she drives better, for the time being her car is simply not as strong as Amanda's -- but for the most part she understands the logistics.

"Pea understands that Amanda's running for a championship," Lance says. "You don't want to hold Pea back, but Amanda does have the best equipment in her car."

The sisters downplay any sibling rivalry; they say they just want the other to succeed. At the same time, they are competitors, and anything short of the checkered flag is a disappointment.

"We always want to win," Amanda says. "That's a given."

The sisters say they've raced against each other, at least officially, about five or six times since they were kids. They say the outcomes were pretty even.

"We pretty much split," Amanda says.

Adds Danielle quickly, "And it's not like the other was far behind or anything."

Both sisters have massive aspirations, and hope to use Old Dominion as a springboard to bigger racing circuits. Amanda hopes to win the Grand Stocks points championship this season, before eventually moving up to the Nextel Cup and becoming the first woman to win the Daytona 500.

Danielle, after gaining more "seat time," takes it a step further: She wants to become the first woman to win a Nextel Cup points championship.

"They have high expectations for themselves," Watts says. "They work hard enough to do those things. I don't doubt them at all."

Amanda's push toward a professional career is becoming more of a reality; after graduating from Fauquier High School in June, she plans to take a couple community college classes this fall while focusing on racing. Lance and the rest of the McDermott crew fully back her lofty aspirations.

"We're going to back her on this thing all the way," Lance says.

Danielle still has a couple more years before she can start a push of her own -- she's gearing up for her junior year of high school at Fauquier.

The sisters don't talk much in the hours leading up to the race. They are in their own worlds. This is the first time they will race each other in the Grand Stock division; Danielle couldn't move into the class until she turned 16 on Aug. 8.

Amanda, decked out in a black jumpsuit, a black tank top and black sunglasses, is almost serene as she meanders about, observing the scene. Danielle, dressed in a blue jumpsuit, bubbles with adolescent anxiety, slap-boxing with her cousin, Kyle Curtis, and talking loudly with Lubkowski.

After putting on their racing equipment: fire-resistant masks, helmets and thick gloves, they climb into their respective cars and are harnessed in. Following final instructions from Lance and Watts, Amanda and Danielle rev their engines and rumble off to the starting line.

* * *

Amanda makes her move about 15 laps into the race. Miranda drifts wide on the first turn, and she darts under him to take the lead. Her No. 13 Monte Carlo looks sleek and powerful, splashed in neon green and black paint, as it speeds down the track.

Lance is bouncing on the balls of his feet atop the trailer. He crouches, follows the trajectory of Amanda's car after she passes Miranda, and then slaps his hands together five times.

"Thatta girl, Amanda," he hollers. "Go, go, go!"

Almost immediately, after sharing in this joy with Amanda, Lance wheels around and finds Danielle's No. 14 car, which is in last place. His smile fades. Over the one-way radio Lance is plugged into, he hears Danielle complain about her car coming loose on the turns. Lance then hears the bad news: Her front right tire is flat. She's essentially unable to compete, but continues anyway.

This is Lance's struggle: Balancing the highs and lows of two young women, the victories and failures of the two people he loves more than anyone else in the world. At times, like this Saturday night, he must revel in one of his child's glory, while soothing the other's despair.

"It's never easy," he says.

It's already been an emotional year for the family. Amanda and Danielle's mother, and Lance's wife of 12 years, Judi McDermott, died of liver failure in June of 2005. The sisters have dedicated their racing seasons to their mother's memory. They both have memorials to her stenciled on their cars.

Amanda only gets stronger during the race, stretching her lead over Miranda by about 10 cars lengths. Danielle lags behind in last place, her flat tire preventing her from any sort of heroics.

Once Amanda crosses the finish line -- her fourth victory in the Grand Stock division this season -- Lance leaps in the air and scurries down the ladder of the trailer and back onto the asphalt infield. His smile seems wider than the track itself. He finds Amanda on victory row, hugs her tightly, and then does the same to Danielle, whose face is flushed with frustration.

"I'm relieved," he says. "I have all eight fenders on my cars, and they got out of them all right."

Amanda, clutching her trophy in victory lane, beckons for her little sister to come to her. They embrace in a long hug, their faces pressed together, their hair messy and full of sweat.

Lance watches from afar, engulfed in happiness as the announcer rushes over to interview both sisters. With the difficult part of this hectic night behind him, he leans against a guardrail, folds his arms and takes in the scene like a content man watching the changing horizon at sunset.