http://www.youtube.com/watch?v=tY0w-...layer_embedded

Here's the my track. Current layout at last saturday's race. Looks to be about 3X the size of yours. So my gearing suggestion probably would not be good for you as you don't really need much top speed for a long straight like at my track. You need more torque to clear jumps and exit speed. May be around 26/75 or 25/72. basically a combo that will put around 7.0-7.5 final drive ratio. Hopefully others on here that run on tight tracks like yours can chime in for suggestions.

Edit: These suggestions are for 13.5.