Takeoff-Motor speed

[lucasantoro]

I attached over the top of the mambo a small sensor (about 20 gramms) but the drone won't take off, but if I perform the takeoff from my hand and I remove the hand when the motors start to spin, the drone perceive that is in the air, so the drone compensate the additional mass and can hover and move.
I think that this problem is related to the weight hardcoded in the firmware, and pid is optimized to perform the takeoff with this weight.
My question is: is it possible to modify this parameter( the weight) o perform the takeoff with more "power"?
Thank you very much