speed up motors, and the amount?

for my robot, i want to put 2 high speed motors in the back, we already have to on our arm. but right now we have a 2 low power motors as our drive. so i want to high speed motors in the back 2 wheel and right now i am wondering if i put 2 low power motors on each wheel, will the robot go faster. I would use up 10 motors total (2 on claw, 2 high strength on arm, 2 high speed on back wheels, and 4 on front wheels). Also i was wondering that if you use 2 splitters could you use 2 extra motors because you would only be using 10 motor ports, but 10 motors.

10 motors max reguardless of how wired and a y cable can not be wired to another y cable. with 2 motors on each front wheel the rpms would not increase to that of one high speed motor. the torques would be more similar than the rpms of the wheel.

If you put the 393 “High Strength” motors with the internal gearing set to speed on the back, and have the standard motors on the front, they will be running at different speeds, which will give undesired results. Either leave the High Strength motors in “torque mode” or gear up the front standard motors.

Also no you are only allowed to use 10 motors total on your robot. Using Y-cables in the competition really has no advantage or purpose. Unless of course you are not using any of the 2-wire motors.