Matt's right. My Formosa flies on a Himax 2025-4200 with 5.66 (C) gearing. Pretty good verticle with 11x8 prop on TP 2S 1900. I know either of our motors will like 3S better but the 2S is adequet and is all I have at this time. With 2S packs, load the motor pretty heavy. I've worked my way up to the 11x8 and I've found my set up really responds well to lots of pitch. I'll probably back off on the diameter when I go 3S to keep the discharge rate within limits. Use Motocalc to get a good guess and max out your discharge rate to about 15 amps. This is a few amps above the continuous rating for the TP 2S 1900 so don't hold wide open throttle too long. I've found performance is so improved over stock that I'm not using WOT all that much. My pack and motor finish a flight only luke warm.

Have fun and let us know what you think of your brushless Formosa.

Randy