The reason the 80 stops to steer is that you have reached the limits of the hydraulics. If the 100 allows you to steer that means the hydraulics are stronger but the net result is you are either trashing the steering system or the mounting system. It does not make it better. It makes it easier for you to steer, but the system is being stressed beyond what it was designed for. You run the risk of the link breaking or bending as well.
If you put hydro assist on the 80 you will have the same steering as the 100.
