AC/DC's Brian Johnson hits the track

AC/DC lead singer Brian Johnson is living the dream as both a racer and a rock star. AP Photos

DAYTONA BEACH, Fla. -- Brian Johnson is a typical red-blooded English/American male. He loves rock music, fancy cars and auto racing -- among other things. But Johnson, who became AC/DC's signature voice after the death of Bon Scott in 1980, is one of the most popular rock singers on the planet. He'll also be driving all night long as part of the 50+Predator/Alegra racing team during the 50th Anniversary Rolex 24 At Daytona Grand-Am race, beginning at 3:30 ET on Saturday.

Hard rock and fast cars offer him the perfect mix.

"It's a funny old world. It's a yin-yang world where all the sportsmen I meet want to be rock 'n' roll singers, or in a rock 'n' roll band, and all the musicians I know they want to drive cars," Johnson said. "But there is something about driving a piece of machinery that is very quick and beyond your ability ... What you're doing is you're always checking the level of your cojones, if you know what I mean. It's one of those things where you scare yourself half to death. So the next time you do it you're not nearly as scared. You just get more and more used to the speed."

The similarities extend beyond noise, power and adrenaline.

"The old saying is, when the flag drops, the B.S. stops, and it's certainly true in racing and in music. With that size audience, this 24 Hours is right up there with the biggest gigs I've ever done. This is the ultimate for me," said Johnson. "It's the pinnacle of American racing -- right up there with the 500 at Indianapolis -- but this is road racing, which has been my passion since I was a boy."

His team will be competing in the Daytona Prototype class. "Most people try to live the dream while they're alive. I think I've outlived the dream," he said.

And what about the noise? His wife, Brenda, puts it this way: "This is much louder than any concert. My ears are accustomed to rock 'n' roll. Nothing can get you accustomed to this."

A lifelong auto enthusiast, Rolls-Royce Phantom owner (he it drives to and from the local Publix and Walmart in Sarasota, Fla.) and competitive racer for the past decade, Johnson published "Rockers and Rollers -- A Full-Throttle Memoir", detailing his passion for automobiles and rock music, in 2011. He was raised in the English mining town of Dunston but now calls Florida home. In the book, he compared getting his driver's license to losing one's virginity. "You'd overcome machinery. You were 'the man,'" he wrote.

This Daytona rookie admits to being a bit overwhelmed by being on the same track with the likes of Scott Pruett, Dario Franchitti and Juan Pablo Montoya. "With all the testing they give you -- the car becomes like a suit. But I'm fully aware of who is driving around me. We really have to look in the mirrors twice," Johnson said.

Johnson hinted at a possible AC/DC sighting this summer. The group finished the two-year Black Ice Tour in 2010. "Something might be in the works, but I don't want to let the cat out of the bag," he said.

For now, his bucket list is pretty much empty. "When I first heard the Beatles sing "When I'm 64," I never thought I'd be doing this when I was 64," Johnson said. The frontman on "Back in Black" -- the top-selling hard-rock album, with more than 49 million copies -- and 11 other AC/DC studio albums, is no backseat driver.

"We know him as a racer. When it's race time, it's time for him to get into the car like anyone else," said Jim Pace, the 1996 Rolex 24 co-champion and one of Johnson's teammates driving the No. 50 BMW/Riley.

That car is much more powerful than Johnson's other rides, including his Royale RP-4, or the 1965 Lola T-70 Mach I – Chassis No. 50 – which he drove in the Monterey Historics last year in California. He finished third in his division.

"The Lola had never been raced before. I took it into the corkscrew [at Laguna Seca] very quickly and I was thinking 'I'm the man. I'm the man.' And as I spun down the hill backwards, I got to thinking, 'I'm not even close to being the man.' But this car [the BMW/Riley] is a different beast ... It's an absolute beautiful car. It's so wonderful, tough, sturdy ... and beautiful, a bit like Marilyn Monroe."

There are no stop signs or speed limits on Daytona International Speedway's 3.56-mile road course (except on pit road). After a successful testing session recently, Johnson was ready for more.

"It was fascinating. I didn't realize there would be so many people out there. All those cars just ruined my day," he said. "It's all a learning curve ... I can't wait to get back in the car again ... It's all baby steps," he said. Then gesturing toward his crew, he added: "Bollocks to the lot of you!"

Johnson was greeted by well-wishers and autograph seekers throughout the garage and pit areas during testing. Among those thunderstruck by his presence were Ethan Darby, 17, and his brother Sheridan, 15, of St. Augustine, Fla.

"It was like a dream. I'm thinking, 'This can't be real,'" Ethan said. Added Sheridan: "He's like an idol. I'm in love with AC/DC. Meeting him, I just flipped out."

(Johnson's team is racing in partnership with "Highway to Help" to raise money for the Austin Hatcher Foundation for Pediatric Cancer research in Chattanooga, Tenn. Fans wishing to help can make a $10 donation by texting "2232" to "501501".)