DAYTONA BEACH, Fla. -- Friday night's first Budweiser Shootout practice at Daytona International Speedway wasn't long, but it was enough to send an ominous sign for Saturday night's special event and the rest of Speedweeks.

It also sent defending Shootout winner Kurt Busch, younger brother Kyle Busch and Penske Racing teammates Brad Keselowski and A.J. Allmendinger to backup cars for the non-points special event.

The opening session of the 2012 season allowed all 25 Sprint Cup drivers to get on track to investigate both tandem and pack drafting. But it only lasted about a half-hour before Tony Stewart bumped Kurt Busch between Turns 3 and 4 and ignited a five-car fracas.

"I was pushing the 51 car [Busch] and he had to move a little bit," Stewart said. "But I'm still the one pushing him so I'm responsible for it."

"It was just a deal where Tony was trying to help, we were just trying to learn the draft and a couple of slow cars were emerging in front of us and I slid up to go around them," Busch said. "I thought it was smooth but I got turned around."

Keselowski had a philosophical take on the events.

"Some guys in front of me got together, it's just the way it is," Keselowski said. "It's the first time that we get back on the track and everybody is aggressive, learning what the limits are. Sometimes you get caught up in that. It's better to do it now than next Sunday [in the Daytona 500]. We'll learn something from it."

Allmendinger agreed with his teammate.

"Everybody is getting the feel of it out there," Allmendinger said of his first practice as a Penske Racing driver. "The 51 car was moving around a lot -- he was three-wide a couple of times. I kind of got through the middle of the three-wide pack and thought that we were OK. When you're pushing somebody and you just get off-centered to the left side of the car, it's going to turn it. To me, that's what happened and after that, I was just behind it."

Stewart's crew immediately set to work to repair his car, with no plans for any more practice. Keselowski, Allmendinger and Kurt Busch didn't plan to practice in the second session.

Kyle Busch's Joe Gibbs Racing team whipped out its backup Toyota and quickly prepared it to run. Busch was sitting on pit road waiting to get on track when the second session was stopped after less than 10 minutes of running due to rain.

About 33 minutes later, after track vehicles and jet dryers tried briefly to stay ahead of the rain, the session was called off.

The sessions seemed to mirror what NASCAR officials saw in January testing at Daytona. The fastest lap in the opening session was 201.762 mph by Matt Kenseth, just ahead of Jeff Burton, who was clocked at 201.739 mph. David Ragan was clocked at 200.151 mph.

In the second practice, Earnhardt-Ganassi Racing teammates Jamie McMurray and Juan Montoya hooked up and tried to work a tandem that resulted in the session's fastest laps, 197.698 mph by McMurray and 197.694 by Montoya.

The consensus seemed to be, in the relatively cool evening temperatures during the second session, that pack racing would dominate any race held this week. But McMurray said if two cars could connect at the end of a race they could prevail.

"I like the big pack more than the tandems so NASCAR's done a good job [of eliminating tandem racing]," said McMurray, the 2010 Daytona 500 winner. "And it seemed like the big pack was [as fast as] the tandems.

"My guess is what you're going to see is a large pack and the guys that can get together with about a lap to go -- because you can't push longer than that or you'll burn the engine up. It's gonna come down to being in the right position and having a little bit of luck."

Montoya laughed and just said "hot" when asked how his car's water temperature had been.

"Just trying to figure out how we got to run and [the car] seems to be pretty strong," Montoya said. "I think it will be a pretty crazy race but it should be fun. To be honest I think we're gonna end up being in a big pack."

That would suit McMurray just fine.

"Our temperatures were fluctuating [and] as much as it cooled down [Friday] night it was better than it was in the first practice," McMurray said. "But it was definitely hot, that's for sure. The 500 will be over before this and it's gonna be hotter, then."

McMurray said the slippery conditions had him even less comfortable.

"It was raining a little bit and when Juan was behind me it was a little hairy," McMurray said. "The bumpers seemed to be grippier and that moved us around [Friday] night. It was a little edgy."

"It's back to pack racing to a certain extent [but] you can see cars just in the pack are already overheating," Allmendinger said. "Everybody is anxious. Obviously, [the Shootout] is going to be a free-for-all. I think there are some lessons learned for the 500 on where to put yourself, and where not to put yourself.

"It's going to be interesting. I still think in the end with two to go, three to go, you're going to hook up if you're at the front of the pack and push each other and just melt one [engine] down trying to get to the line. It's definitely back to the way it used to be."