Dale Earnhardt Jr. and Graham Rahal are used to occasional fireworks when drivers get upset at the track.

They saw the real thing Wednesday visiting Indiana National Guard troops at Camp Atterbury. They got an up-close look at some of the weapons and explosives used and they honored soldiers who recently committed to the National Guard and others who served in Afghanistan. The two drivers are sponsored by the National Guard, and they loved every moment.

"Oh yeah, they're entertaining us," Rahal said after setting off an explosive so big that mud and clay landed nearly 300 yards from the detonation site. "We're not entertaining them. They're the experts, we're learning from them. It's very cool, very unique."

Nearly 4,000 troops are in the middle of training at the camp 45 miles south of the Indianapolis Motor Speedway, where Earnhardt will compete at the Brickyard this weekend. He and Rahal, an IndyCar driver, were scheduled to fly to the camp on a Blackhawk helicopter, but thunderstorms altered the plan.

The drivers' first stop was with a brigade out of Evansville, where Earnhardt and Rahal fired a big Howitzer.

"Most of the time when we're out here shooting, we don't see anyone out here," said Matthew Gumbel, who instructed the two drivers on how to fire the weapon. "It's great for the spirits of the solders."

After taking a couple of shots, Earnhardt and Rahal presented the new recruits with replica cars. Earnhardt gave the brigade a signed car hood and Rahal presented a fire suit, and Earnhardt swore in six soldiers who recently committed six years to the National Guard.

"That was really overwhelming because I'm sure that opportunity will never come again," the Daytona 500 winner said. "That was really a unique experience. I had the sign the (script) so I will never forget it."

The drivers recognized soldiers from the 713th Engineer Company, where they detonated explosives, and did a question and answer session before honoring soldiers from the 219th Battlefield Surveillance Brigade.

Earnhardt and Rahal left the base in the Blackhawk helicopter.

"It never gets old being able to come out here and see these guys in their environment," Earnhardt said. "You get a real understanding of what's going on behind the scenes, how they train and how they prepare, and what the commitment is all about."