As you come into the airport, there are always a couple cool examples of historic Indycars...usually one at each concourse, plus another display car in the center section.
You're a race fan. For sure go to the Speedway Museum. There's a lot of cool history in there. I've also done the Speedway tour, but I was sick (and half delerious with a fever) when I did it, so I don't remember much. I'd do it again. 
A stop by Dallara (1201 N Main St, Speedway, IN 46224) is also cool, and close to the Speedway. One of our members works there, and Steve Cox and I got the behind the scenes tour a few years back. But there are some cool displays out front.
I looked at a few of the big race teams (Don Schumacher Racing, Andretti Autosport, Ganassi), and it looks like they don't have much for tours.
Have fun!