The multi-car wreck, which occurred almost an hour into the four-hour afternoon session, was triggered by contact between Marcos Ambrose and Dale Earnhardt Jr. at the front of the pack. By the time the smoke and dirt cleared on the backstretch, 10 cars were headed to the garage.

The cars of Jeff Gordon, Jamie McMurray, Brad Keselowski, Kasey Kahne, Carl Edwards, Kyle Busch, Joey Logano, Regan Smith, Greg Biffle and Aric Almirola were the others involved.

The wreck temporarily halted the first major drafting sessions of the 2013 season on the 2.5-mile track. Biffle was one of several drivers to find the new car a handful in traffic, saving his car from a near spin at the exit of turn four earlier in the session.

With rear deck lids in short supply and no backup cars available for teams other than Edwards’ Roush Fenway Racing outfit, the wreck effectively ended testing for most drivers involved.

"I didn’t see anything," said Keselowski who was near the front of the pack when the wreck occurred. "I saw cars smoking and wrecked in front of me. I think I ran into the back of the 43 (Almirola), and someone ran into the back of me. That’s just the way this deal is. It’s unfortunate, but sometimes you’ve got to wreck ’em to learn."

For those, including Earnhardt, who test sessions didn’t end with the wreck, there won’t be any more pack drafting when drivers return on Saturday.
 
"We’ll go back to single-car runs," Earnhardt said. "I don’t think anybody wants any more drafting after that. So we’ll just go back to running single-car runs. We’re probably going to be here till 5 o’clock tomorrow working on our cars. We’ve got to find a little more speed."

In the morning session, Jeff Burton surged to the top of the Day 2 testing leaderboard in his No. 31 Richard Childress Racing Chevrolet SS, clocking a lap of 194.805 mph. He was followed closely on the speed list by Childress teammates Kevin Harvick (193.557) and Paul Menard, who ranked fourth-fastest at 192.963.

Defending Daytona 500 champion Matt Kenseth, who topped Thursday’s opening session, was third-fastest early Friday at 193.121 mph in the fastest Toyota. Biffle ranked fifth overall on the speed chart with the fastest Ford at 192.719.

The first session was interrupted by two caution flags, including the first crash of the sixth-generation car. Dave Blaney smacked the outside wall on the exit of turn 2, damaging the right side of the No. 36 Tommy Baldwin Racing Chevy. Blaney was uninjured, but the incident brought an end to testing for the single-car team. The other caution flew for debris.

The three-day test concludes Saturday with seven more hours of on-track activity scheduled.

Contributing: Reid Spencer, NASCAR Wire Service

“Last year (in 2011) the way we lost our competitiveness and Tony (Stewart) and Carl (Edwards) ran off with the show, the season couldn’t end fast enough,’’ Johnson said Friday from NASCAR’s Preseason Thunder test at Daytona International Speedway. “The offseason was nice to have and it seemed way too short. There was a lot of recharging that I needed and I think the team needed.

“This last year (2012), I wasn’t ready for the season to end. Sure I would have loved it to end after Texas when we had the points lead and we could be champions, but I honestly had more in the tank when the season was over.

“I think I did a much better job of managing the pressure and stress than any other year. I think (crew chief) Chad (Knaus) did, my guys did and although it came to an end, I could have gone the next week and raced again. I had more left. I enjoyed the offseason, I had fun, but I’m ready to go racing.’’

The eagerness is apparent. Two days into the new season’s first test, the future Hall of Fame duo is reminding others what makes them so successful.

Johnson was the only member of the four-car Hendrick Motorsports team not involved in a 12-car accident during the afternoon portion of Friday’s test.

And it was a calculated decision — made before they even arrived in Daytona Beach– not blind luck that kept the No. 48 Lowe’s Chevy out of the fray.

“For us, it makes no sense to go out there and draft because you aren’t going to learn anything,’’ Johnson said about an hour before the multi-car accident. “You’re just taking a chance of ruining your best race car.’’ 

And that’s exactly what happened to a few of his competitors Friday when his Hendrick Motorsports teammate Dale Earnhardt Jr. triggered the melee while experimenting with the draft. It was the first time a large group of the new Generation-6 cars had tried to draft. Earnhardt, like the others, was simply trying to see how the new body styles matched up.

With a lot of damage to a lot of cars — and not many backups ready for the track — several teams opted just to pack up and end the test early.

Reigning Sprint Cup Series champion Brad Keselowski was among the Ford contingent that cut their losses.

“Looking to draft but all my friends are heading home now,’’ Johnson joked later on Twitter as the sound of private jets heading back to North Carolina could be heard above the roar of the remaining cars on track.

Instead, Johnson will stay in Daytona Beach, methodically developing the Gen-6 Chevrolet SS, preparing to utilize any advantage the extra track time might create.

He’s got another championship to win.

“I think historically, changes have been good for the 48 and good for Hendrick,” Johnson said. “I hope and assume that we will be in that front wave of guys figuring things out.’’

While it may be a bit of a psychological plus, the reality of NASCAR competition is that it’s more important to go fast on the track, something that isn’t lost on Keselowski or his team. And on Thursday, that wasn’t the case. By the time the opening day’s on-track activities had subsided, Keselowski had mustered only the 31st fastest time.

That might have raised an eyebrow or two from some, but most know that this week’s test is about gathering information. With the new Generation-6 car making its debut, teams are working through the processes that they hope will unearth not only speed but drivability as well. At this point in the season, the reams of information flowing through tables filled with laptop computers in each of the garage bays at DIS likely paint a clearer picture of which teams are making the advances that will pay off when it matters most.

Still, Keselowski admitted he wasn’t thrilled with his car’s position on the scoreboard through the morning session, which was also 31st out of 34 cars making runs.

“I am not happy not being fast, I can tell you that, but you try to put it in perspective of how much work is yet to be done over the next month or month-and-a-half,” he said.
Taking into consideration the arrival of the new car, Penske Racing’s switch from Dodge (which departed the sport at the close of the 2012 season) and Keselowski’s previous history –- he admittedly has been a notoriously slow starter once the season begins –- he sees little reason for concern. He doesn’t want to use the latter, he said, as a crutch for explaining away any shortcomings early in the year.

“If you win a championship, you are going to come in the next year with extremely high expectations,” he said. “For me, you have to look at our history, and we have been a second-half team the last two or three seasons and I would expect nothing different this year.”

In last year’s title-winning campaign, Keselowski didn’t crack the top 10 in points until the season’s 12th race had been completed. The year before, it took 26 races.

“I don’t want to build in an excuse for our team so I am not going to say that if we don’t run well at the start of the year we have nothing to worry about,” he said. … “But I think you can apply things logistically and know we are the type of team that gets stronger throughout the year.

“That is probably the best way to be."