Originally Posted by
VenturaDC
Because the esc has only so many amps to send the receiver and servo at the same time, usually 5amps at 6v. When the pack is fresh it's easily doable, but after a few minutes when the voltage has dropped a little the savox servos are known to pull high amps basically using what is available not leaving much for the receiver.
If your at full steering and powering out of a turn, the voltage drop from the motor digging deep and the servo pulling higher then normal amps(savox is known for this) then the receiver "browns out"
Castle BEC, again is the answer. Its really simple, using a bec you will never pull more amps or voltage from 1 savox servo that a good quality BEC can supply. As an added bonus you can run it at 6v getting faster movement and more torque.
Bolded because its the correct answer I highly doubt any thing else could cause what your having problems with. Dont add a cap or any other bandied setup, just run what will for sure fix the problem.