whats the weight balance on this truck as to me from they videos you posted it seems that there's too much weight at the back of the car which seems to make the car a real handful.

Perhaps you could replace your 8000mah truerc cells with some lighter flightpower cells with a higher discharge capability.

The runtime will be reduced but i think the truck will handle much better considering how far back the cells are in your configuration.

just a thought.