The A123 cells are rather neat. They are not as fragile as lipo's. Thoug they drop in voltage pretty bad under a high load, which makes them less powerfull than enerland lipo's

BTW, their name is not lipo, it's lithium ion.

Plug the values of your setup into the speed calculator thingy to get an idea about the speed difference.

Runtime is highly variable - driving style, temps, terrain, weight, etc all play a role in runtime and is impossible to calculate accurately.

sorry, im not real up todate on my terms:dft012: maybe ill just stick with my GP's

I am using the GP's also.. they are great for everyday bashing/driving.

ok, cool. then ill just stick with them and get me a motor and ill be good!

Save your money on the RR ring and pinion and just get a good alumunim cup and housing. The RR ring and pinion doesnt last any better than the traxxas hard gears, and the traxxas gears are half the cost.