There's no way of telling what speed a particular motor can make just by knowing the number of turns is has. In fact, the number of turns in a motor tells you absolutely nothing that will ever do you any good. Doesn't say anything about the motor's maximum current draw so you really can't tell if a particular ESC is going to work with it. Really a very dumb way of describing a motor.
Motors with fewer turns tend to spin faster than motors with lots of turns. Does a motor capable of very high RPM under no load mean that it's gonna make for a fast boat? Nope. That's because it doesn't tell you what RPM the thing is capable of when it is loaded down with a prop. (It'll be considerably less than it's no-load RPM - lol !)
The number of turns in a motor is a very poor way of comparing motors. But it's a very good way of selling them!
- 'Doc