I think the njba mostly runs out west, here is their website.
http://www.njbaracing.net/
A few other sanctioning around here. St louis dragboat assoc runs in IL.
http://www.sldba.org/
Kentucky drag boat assoc runs nearby also
http://www.kdba.net/
...and the Blarney Island races up by Chicago on Thursday nights, you can watch them right from the bar/resturant on the water.
http://www.blarneyisland.com/boat-races.php
and of course my personal favorite-Hydroplane racing. You need to go to Madison or Evansville if you havn't been. ABPA ran an outboard hydro race in right down the street from you in Peoria last year, or at least some of one. Final heats were blown out due to high winds.
Tons of Hydro info here:
http://www.hydroracer.net/forums/index.php? or here:
http://www.abrahydroplanes.com/index.cfm?page=Home