Here in New Zealand we have always run a silver can class. In fact it is our stock class and at a big meeting like the nationals this class in whatever form of racing Touring cars, offroad etc is always the most popular. Because we have run it so long I guess you can say the guys here have learned alot of tricks. Loke the gearing they run. They basically get the smallest spur they can buy and the largest pinion. Something like a 88 spur to a 55 tooth pinion.
Also because of some cheating that has happened over the years we have a rule about the amount of current the motor can draw when tested. If it draws to much current you are disqualified. The other thing is that the cars are limited to 1400mah batteries unmatched. They are also limited to using rubber tires. (we run foam tires in the other classes here.)