E47 injection timing

[Chevyguy]

I'm working on a delete tune for a 2015 cruze diesel e47 ecm. Using efilive v7.5 .All emissions are deleted. Main injection timing table how much do i advance timing? AI says its heavily retarted for emissions and it should be -8 around 1750-2000 rpm. its currently around zero. In the 80 mm3 row it says -15 and currently 20.8 at 4500. My understanding negative numbers are btdc and positive are . just seems like a huge jump in timing. any help is appreciated. attached is current injection timing