From the optimum configuration, the big nose, when first installed, showed worsening of total lift and front and rear lift as well as moderate increase in Cd (30-40 counts). Dave Salazar suggested that was screwy and we checked and found that indeed the install crew had made minor error with the bottom of the splitter not parallel to the floor. With that corrected, there was slight improvement in the Cd (but not to optimum level) and much improvement in front downforce. Rear lift was slightly improved but did not go negative ( ie still lift, not downforce)