No, putting it in the center would just be silly. For one, the track would set too far back from the grandstand. The crowd would feel disconnected from the racing action, since, even at their closest point, the cars would never be that near to them. Secondly, if you put any degree of banking at all on the track you would obstruct the sight line to parts of the pavement track. Probably in the turns, where a lot of the passing takes place. Let alone trying to put up additional infield bleachers. That would really create even more blind spots.

As some of the others have suggested, Indiana is already dirt track rich. There's probably not a market for another venue. Especially a marginal one, like you're proposing.