Originally Posted by
howardcano
There's a very simple solution to this. Use an optical tachometer (less than $20!) to tech the RPM of the driven wheels at 8.4V and full throttle. Set your maximum allowed value to something sane that can be achieved by any 21.5 motor. Some motors will end up with more timing than others to reach this RPM, but the performance will be the same (given that the maximum usable torque is determined by wheelspin on a FWD car).
The optical tach method has been used by RCTech user Meradin for VTA, and he reports excellent results.
Imagine: no more motor wars!
We actually looked at this. I even got one from eBay: $15 shipped and it's pretty accurate. A few of us even discussed electronic rev limiters. But, it comes down to there being a will to do tech. That's what's really lacking and why we moved away from silver cans in the first place. If there's one thing I will praise Tamiya for endlessly, it's running a tight ship at the tech table.
Very glad I'm not much of a decision maker anymore and I can just bitch about stuff. Life is good!