This weekend will see a select group of Sprint Cup drivers in race action for the first time in 2013, as they compete in the Sprint Unlimited exhibition event at Daytona International Speedway on Saturday evening.

It'll be the first time the Generation 6 Cup cars have been in proper race action after a winter of testing and development for the new-style equipment, but unfamiliarity with the handling of the new cars wasn't a contributory factor to the early crash during Friday's practice session that ended up damaging five competitors' cars less than ten minutes in.

"That was 100 percent driver error," admitted Matt Kenseth afterwards. "My driver error."

Kenseth was exiting turn 4 on the 2.5-mile track and moved down without realising that Kurt Busch was underneath him. The two cars collided, turning the #78 into the wall and sparking an accident that also caught up Juan Montoya, Mark Martin and Carl Edwards. Busch, Martin and Edwards all needed to resort to their back-up cars for the rest of the weekend as a result of the damage incurred.

"I had no idea anybody was there, and he had a run at the same time, and I came down in front of him, and he couldn't get slowed up from staying out of me," explained Kenseth, who insisted that the new Gen 6 cars had nothing to do with the incident. "It doesn't matter what kind of car you're driving: you drive down in front of somebody, they're going to hit you."

"I feel bad that it happened," he added. "It seems like the cars are real good. My car was real fast before I tore it up."

Busch explained that it had been a simple misunderstanding between two drivers. "Matt went high, and I think he expected me to go with him. I went low to go with Kyle, and I think Matt came across our nose," he said, adding that it was a tough break to already be reporting to the Furniture Row Racing back-up car this early in Daytona Speedweeks.

"A lot of hard work goes into these cars, and six week's preparation can be trashed in six laps," he said. "It's tough."

Carl Edwards was more philosophical about the incident, hoping that early bad luck at Daytona might prove to be a good omen longer term for the 2013 Sprint Cup championship overall.

"Last year we came down here and we sat on the pole for the 500, and everything was cool and smooth and our year went terrible," Edwards explained. "Hopefully, this is all our bad luck!"

Kevin Harvick went on to top that practice session's timesheets with a lap of 45.601s (197.364mph). The second session was a quieter affair with only 12 cars at work and most making solo runs rather than trying to simulate race pack drafting conditions, and consequently Denny Hamlin's lap of 45.906s (196.053mph) was slower in the cooler twilight conditions. (See full results.)

The Sprint Unlimited is not part of the regular Sprint Cup championship, which begins next weekend with the Daytona 500. It is an exhibition race only, with entry limited to drivers who won a Cup pole position in 2012 and to previous winners of the event.

That means that the 2012 Sprint Cup champion Brad keselowski and runner-up Clint Bowyer will be watching the event from the sidelines in pit lane. In total, 19 drivers are eligible to compete in the race, headed by the 2012 event winner Kyle Busch.

The format of the Sprint Unlimited - previously referred to as the Daytona Shootout - is always something of a moving target and this year is being decided by fan vote. The result of the first of the votes deciding the overall format of the race was announced mid-week and determined that the race will consist of a 30 lap first segment, a 25 lap second segment, and a final 20 lap run to the chequered flag. That option was preferred by 55 per cent of voters.

"The 30-25-20-lap format the fans voted for will create three distinctly different segments that will keep fans enthralled throughout the race," said Robin Pemberton, NASCAR vice president of competition, who added that the vote component would create "unprecedented buzz" about this weekend's event.

Additional votes about the format of the pit stop at the end of the first segment, and how many cars will be eliminated at the end of the second, will remain open until the start of the race itself.

See practice times.