Turns is an indirect indication of kv (how many rpm a motor will turn for each volt supplied). It actually refers to the number of times the stator is wound. Less turns=higher kv=faster and more power use. For a mix of rally and asphalt, I would suggest not going over 5000kv. If only asphalt, then you can go higher. Very high kv is only for short, very fast runs, they get hot fast.