[TonyM]

Try the ESC Acceleration setting, which can only be done via the PC interface as it is not an option on the quick setup board. Set it on high and see how that feels.

Also, check that you don't have a negative Exponential setting for throttle on your transmitter - you might even try moving this into the positive.

Then of course the pinion needs to be selected to suit the track size and complexity. If you have fitted a pinion for top speed say 23 and above the low end acceleration will be less than if you were running say a 21 on a short track.