A higher turn motor will produce more torque, but it will only do so at a higher voltage. At the higher voltage, because of its lower KV, it turns at the same speed, but produces more power, which is seen as torque.
Just dropping a high voltage motor in as a replacement for a low voltage motor will give lower rpm, but will not give more torque with the same battery. It will run cooler because it is not dissipating as much power, but at the same time it will be offering less power to the shaft.
It's a sound engineering principle to remember that what comes out of a system, must have gone in. What you get out of a motor, depending on its design and how it is used, is turning force, rpm and heat. All of this comes from the charge in the battery. A good combination gives the rpm wanted with the torque to do the job with the minimum of waste heat. Finding a motors comfort zone does not equate to looking at a data sheet and going for "max efficiency". Running a motor in that condition usually results in a short lived motor. Its the point where practice trumps theory every time.