He use Dean Connector with a 6 cell nimh duratrax DTX4200 on a challenger 19t spec with a ratio of 6.5 ( like the motor manual suggest), with a duratrax intelispeed 16t mod and no connection between motor and ESC.

The ESC/Motor really steal all the juice when you snap the throttle this must be the problem. So maybe the receiver is too cheap , or the esc cut the juice on the receiver (I use the same ESC with a 19t team checkpoint without trouble ( except the brake/reverse mosfet burn but that another story).

I will buy this capacitor probably in a electronic shop so when I ask what kind of capacitor I want to know the UF of it and the Voltage ... not really where to get it.

On the picture of the capacitor on the link you can see 4700uF and 10v is that what I have to find or there better uf / voltage choice?