Taken from Florence Family Fun (who you should totally check out):

"Are you a racing fan? Got kids that like racing? On September 26 and 27, 2009, the Darlington Historic Racing Festival is returning for its second year. There will be question and answer sessions with NASCAR legends, race car showcases featuring stock cars, Indy roadsters and a variety of other cars, exhibition laps, a display and vendor area, autograph sessions, and more. Tickets are free for kids 12 and under. Adults pay $15 per day or $25 for a two-day pass. You can buy tickets online at http://www.darlingtonraceway.com/"

Also, SCNow.com has a great list of all the events for this weekend. Check them out here.