Firstly, are you telling me to know about engine accl or that u say I dont know about it at all? Any way, just to remind you, the last 50% of jet thrust is controlled by the last 20% of the engine RPM. When u are performance restricted by Vmcg on a fixed derate, the book says not to firewall the live engine for an engine failure at V1. This is because your controllability has been factored to this lower speed, and getoff the ground with enough control.( Sure ,u've seen this in the sim).But on an assumed temp T/o with full or derate u need to move up the TL as ur present thrust is way low and the Vmcg is not restricting u.
