The OEM sways are at a point (relative to Dinan) in the longest position. This OEM setup is designed to give maximum understeer to the car when combined with the staggered tire fitment. Reason: so the car is more likely than not to go nose first into any out of control setting thus activating the SRS airbag system and protecting the driver or passenger. But of course, this is designed to be the case with the DSC on. DSC off, completely different (for those of us who experienced the wet skid pad at the DE can attest to that interesting oversteer experience).
Moving the setting to the maximum inside setting (000X X000 front, 00X X00 rear) will produce the minimum amount of understeer but not produce any appreciable oversteer with the DSC on, but.... with the DSC off, again once the entire stable of 400 ponies are unleashed, esp. on a slippery surface like hot tires on a hot track, well watch out for getting dizzy as you do some 360 revolutions! Learning, repeat, learning to drive the Z8 without DSC on, with the proper modified suspesion set up can be very rewarding but does take some practice. I personally like the all the way in settings and the way you can nearly "drift" the car through various turns, something, I found was much easier to control once I had the Dinan Sways installed. Before, hard to find the "groove" or balance between understeer and oversteer, IMHO.