do your self a favor, go to a local autox event. press the VDC button once before you start your run. drive the piss out of your car and notice that it doesnt bog or pull punches as you corner aggressively.
Turn it back on and do your next run. notice your time is drastically slower due to VDC cutting you off most of the time during cornering maneuvers and so on.
You are running full open diff mode with VDC off. VDC is not reducing wheel spin or traction loss. The center diff is doing its job, which is deviding up the power to the wheels that can make the best use of it.
Thanks for the rez i was looking for what models and what ratio I needed to get a VLSD from.