Thanks guys, I might try wood... Gary I cannot regear this motor as the gearbox comes from factory. a 15 X 8 e-prop will draw too much current, well this is only software prediction, still I've ordered a 14X7 and 15X8 e-props and a 15X6 wood and see what happens in real life with a wattmeter...
Thanks and best regards,
Homero