its all in the rear geometry, what sort of traction rod mods and cradle angle mods are you using?
Remember to set up the traction rods you need to set it up on a wheel aligner without the rear shocks and simulate wheel travel and andjust them to the pont where there is as little toe change over the travel as possible (use you ride hieght as the cetre point). Secondly we had the same issue at eastern creek where the wheelworx car got way off the line and cat lost the second battle purely on lack of proximity. Changing to super pineapples extra 6mm inclination on the cradle has now fixed the launch issue and helped alot with drive out of corners.
check your lower control arm bushes too, i have seen huge dynamic changes in toe due to worn lower bushes.