To maximize the frame rate of your camera and grip, you need to maximize the speed of each part.
For the grip, you need to use either the big D3 battery (EN-EL4a) or the AA batteries. Using another of the camera batteries limits you to 5 fps.
For the camera, you need to turn off all the stuff that slows you down: You will need a shutter speed of 1/250 or faster. If you are shooting raw, use 12-bit files. Auto ISO will cost you about 1/2 frame per second. All noise reduction needs to be turned off. If your lens has VR, it needs to be turned off. Focus mode should be AF-continuous. Release mode should be "release". "Focus-release" will slow you down but maybe not much. Fewer focus points (21, 9, 1) are faster than more (51) but require you to do your part.
---------+---------+---------+---------+---------+ Joseph K Seattle, WA, USA