They walked through the hospital wards and talked with the wounded, signed autographs, posed for pictures, and for Biffle, gained perspective.
"Everytime I come here, it's a pretty overwhelming experience," said Biffle, the winner last week at New Hampshire. "This is my fifth year in a row coming. To see the dedication that these men and women have that have served our country and continue to serve our country, it makes you feel pretty small.
"Compared to what they have done and what they do for us ... its a pretty grounding experience, I think, for all of us."
Busch, whose No. 18 car was on display at the hospital, said it was an honor to visit the men and women who allow drivers to perform on Sundays.
"It's a great event that we are able to come out here and see them and put some smiles on their faces," he said. "And see that they are not only ready to get back at it, but they are disappointed they are not where they want to be."
Claudia House-De Alba, injured in Iraq, was able to get a look under the hood and inside Busch's car along with Mark Martin's Army-sponsored car.
"Its pretty cool because you only get to see them when they are on TV, so it's nice to see them in person and see how the driver can get out of the car after really bad crashes," House-De-Alba said.
"Instead of playing with GI Joe's when I was growing up, I was playing with catalytic convertors and torque wrenches," said Kevin C. Miller Jr., a member of the New York Army National Guard out of Troy, N.Y., who sustained a severe leg injury while serving in Afghanistan this past July. "My father taught me about racing ever since I was little and I'm a single father, too, so I teach my son about cars as well."