Pickle, 81T/23T gives you a FDR of 8.27. Personally, I don't find that outrageously low for a 10.5T motor... but then again, that depends on track style, driving style, and a whole bunch of other things. Whatever your gearing or track, or driving style, you need to gear your Bmax according to temperature in line with the motor manufcaturer specs (each motor is different in this regards). In general, they usually recommend no higher than 150-160ºF at the4 end of the run.
What you need to do is setup you car with the gearing you want, then drive it on the course for 2 minutes, pull over and immediately check the temps. if it's still cool, drive another 2 minutes, pull over and check... Still cool? another 2 minutes and check... If you can make it through 6 minutes without going over your heat threshold, you are OK (or undergeared if you are way under the threshold). Then, you can start making gearing adjustments 1 gear at a time checking temps at the end of your race practice heats.
This is the only safe way I know of to set gearing properly for your motor. Also, as others suggested, a good heatsink/ fan combo can reduce your motor temp up to 10ºF...
Hope this helps!
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