New Motor + Differential = TOO powerful??

[Synthesis]

I'm still pretty new to the Dnano world and learning as I go so bear with me.

I recently bought the X-Speed motor for my Audi R8 Dnano along with a ball bearing differential and decided to take it for a spin my HTUSA's track. I set it on "training" mode to see if I could notice any major changes and I could see a slight improvement (Running 6 - 6.5 second laps consistently on 3P Infeld). After a few practice laps. I put it back on normal mode.

The big problem is I now have almost ZERO turning radius as it just plows straight into the walls.

Is the combination too much for the car to handle?

I also recently bought a McLaren F1 GTR and paired it with the same remote. Could that be the problem as well? Should I invest in the gyro?

Wes