http://www.scriptasylum.com/rc_speed/index.html

try this out. Works wonders.

Is the 2650kv a shorter can than the 2200kv?

Yes sir. 2650 is based off the 1512 series. And the 2200 is based off the 1515 series.

So what's better, 2200kv on 6s or the 2650 on 5s? I'd assume the larger can would be alot more powerful and more efficent?

Surely if you are considering 5s why not just use the 2200kv and gear up accordingly if you want to match speed.

well a 2200kv is best fora heavyier vehicle such as a erevo ,emaxx or truggy or lower kvs u can volt up and have less strain on electronics, larger kv( 2650) have more rpms more voltage more heat,more strain. hope that makes sense

we run the 2650 on 6s with no issues (speed runs only of course). 50-60mph is definitely attainable on both 4s and 5s. If you arent shooting for crazy speeds (100mph+) like me though, try out a 2200 on 6s. You won't be disappointed.