When it comes down to it, all a racecar driver really wants to do is to go faster. A slowpoke wants to catch up to the pack. A driver in the pack wants to run at the front. A driver who finishes at the front wants to win every weekend. Speed consumes all of them.

Darrell Waltrip, the former stock-car champion who has become an immensely popular racing commentator for Fox, has an on-air catchphrase for the stock-car driver's craving: "Boogity, boogity, boogity." Step on it. Go even faster. Waltrip knows all about how it can grip a driver, and how, when a driver does less well than he used to, the craving becomes an obsession.

In two seasons-1981 and '82, Waltrip boogitied like no one else. He won an astounding 24 NASCAR races, 11 more than any other driver. He won two championships and was on his way to a third. But "we had a tough year in 1983," says Waltrip in "Darrell Waltrip One-on-One: The Faith That Took Him to the Finish Line," a book of 60 devotions that read like a trackside spiritual autobiography. Waltrip's team won only two of the last 19 races of the 1983 season and lost the championship to Bobby Allison by a scant margin.

That same year, Waltrip's wife, Stevie, had her second miscarriage. The combination of personal and professional letdown inspired Waltrip to renew his Christianity. "Before that, Stevie would say, 'We need to go to church,' and I'd say, 'I don't have time. I`ve got to race. That`s my job. Sorry, I can`t make it,'" Waltrip said on the phone recently from his home in Franklin, Tenn. Suddenly, the man who felt "like the Muhammad Ali of NASCAR" had time for church.

That "miserable" season did more than get him to church on time. Waltrip soon discovered a much more substantial flaw about himself than his obsession with winning: "It was all about me," he says of his career.

That realization led the Waltrips on a faith journey that in turn led them to found a ministry, Motor Racing Outreach. These days, MRO has has expanded into a full-fledged church on wheels. Come Sunday morning, wherever the NASCAR tour brings the congregants together, drivers, mechanics, pit crew, and their wives sit on folding chairs, usually in an empty garage, for interdominational services. Waltrip had won 84 races and $19 million before he stopped racing stock cars in 2000, but he says the ministry is his proudest racing accomplishment. "If we weren't able to have a church on the road," Waltrip says, "guys wouldn't be able to get to church."

The new devotional is another way he has put his NASCAR fame to a higher use. "Everything I know pretty much revolves around racing," he says. "Like any athlete, you have a lot of trials and a lot of tribulations, and you make a lot of errors. The highs are never as high as the lows are low. So you just have to have something more than material things," he says. "You have to have some faith to get you through the tough times."

To help tell his story, Waltrip teamed with Jay Carty, a one-time traveling minister who had co-authored a similar book with UCLA's legendary former basketball coach John Wooden. Each of Waltrip's on-track recollections is accompanied by what Carty calls "a Biblical spin." Aside from the Bible, Carty may be all the Wooden and Waltrip books have in common. The principled and organized Wooden never drifted too far from the straight and narrow. "At the other end of the spectrum, you've got D.W.," says Carty. "You've got this wild man who terrorized everything."

At 57, Waltrip still moves fast. His is the father of two daughters, Jessica, 17, and Sarah, 12. Besides manning the booth for Fox and his outreach work, he still drives in a handful of truck races every year just for fun. (In August, he came in 28th in a race in Indianapolis.) "The Darrell Waltrip Driving Experience" a stock-car theme park to be built in Pigeon Forge, Tenn., will soon be putting more demands on his time. "I figured it would be like herding cats trying to get D.W. to sit down to interview him," says Carty.

At the outset of his NASCAR career, Waltrip was such a whirlwind that the rookie from Owensboro, Ky. picked up the nickname "Jaws." It was not intended as a compliment. Younger drivers were supposed to shut up and drive-not at all the voluble Waltrip's style. He eventually won two Most Popular Driver awards, but his first didn't come until 1989--four years after his third and final championship in 1985. "I thought it was a show, and I was a showman," Waltrip wrote in his racetrack autobiography, "D.W.: A Lifetime Going Around in Circles." "I thought I was a showoff, and I could have a lot of fun when I was winning. . When I had my mojo working, I rode it."

His talk can still lead to trouble. This Spring, Waltrip found himself locked in a verbal sparring match with the energetic and brash driver Tony Stewart Waltrip said on the air that Stewart should be suspended for rough driving. Stewart countered by saying Waltrip had hung on for too long as a driver. But where the younger Waltrip might have found himself in an extended feud, today's mellower man backed away, and the spat ended soon after it began.

Aside from his mouth, Waltrip never had much in the way of vices. He was simply so occupied with racing he had no time for anything else. Then, on a hot August night when there was no race, he agreed to go to a Wednesday church service with Stevie. Waltrip remembers being more of a spectator than a participant. He began each prayer with, "Lord, this is D.W., in car No. 17."

"I figured the only way He knew me was by my car number," Waltrip said.

Then 36, Waltrip had reached a point in his racing career where he could appreciate the success he had, but his struggles that summer had caused him to look at what his life might be like without trophies and regular trips to Victory Lane. "Every once in a while, you realize you're not invincible," Waltrip said.

He continued to go to the Wednesday night services. At the racetrack each weekend, he and Stevie would meet with Lake and Lisa Speed, another NASCAR driver and his wife, for Bible study. Bobby and Kim Hillin, another couple, joined them. The meetings grew into a ministry called Racers for Christ, which would develop into Motor Racing Outreach in 1988.

The couples were soon joined by Max Helton, a minister, who wanted them to form a ministry that would have a regular presence in racing. Helton infused the project with the energy--something none of the three couples could provide because they had a race to worry about almost every weekend. "At first," Waltrip said, "we thought, 'Uh, oh, this guy must be some kind of a nut. Why in the world would anyone want to do something like this? We were a little skeptical."

By this time, Stevie Waltrip, a devout woman, had already been taping a Scripture verse to the dashboard of her husband's car before each race. When MRO was not only accepted in the garages but began to grow, Waltrip too it as a further sign that keeping his faith was well worth the effort, whethe he was winning races or not. "A lot of people make a deal with the Lord," Waltrip said, "but being a Christian is probably just about the hardest thing you can do. A lot of people sit on the fence."

Some stay there, some fall the other way, and Waltrip said that is the way it goes. He analyzes races for a living, but he does not want to be judgmental of others. All he knows is that when he discovered a baseline other than a speedometer, his life changed. "My favorite saying is, 'You can't have a testimony without a test,'" Waltrip says.