Unreal POWER and efficency for
Trex 3s or 4s Lipo, we have been testing just about every motor on the market looking for the best efficency/ performance for extreme unlimited tork for 3d flight and to date the medusa wins hands down the best performance of ANY motor on the market !!!
we recommend are(we flight tested extensively):
3s setup medusa 28-32-3400 on prolite 3s 2000 or new 2100 Align 16c
thunderpower 2000mha , 2100 pro lites
we recommend using heat sinks and proper pinion sizes

trex or Shogun on 4s or 3s, 10tooth is Crazzzzy Power

Details:

With all of the brushless motor choices available on the market, it is important to understand why we are different. Anyone can wind magnet wire and assemble a motor, but only a few can design a motor specifically for the RC enthusiast. All of our motors are designed in the USA by Medusa Research's experienced electric motor engineers, and were created with the needs of RC models in mind. Our design is the result of cutting edge computer simulation and years of real-world testing. For performance, price, and quality of workmanship, our motors are simply the best on the market today. Medusa's 28mm motors are designed to be speed 400 replacements. These motors have identical mounting screw locations and come in 3 different lengths. The wide selection of Kv ratings make it easy to select the motor with the perfect size and power for your model whether it is direct drive or for gear drive applications.