  We calculate the baryon flow $< P_x/A(y) >$ in the energy range from .25 to
$\le 2.5 AGeV$ in a relativistic transport model for $Ni+Ni$ and $Au+Au$
collisions employing various models for the baryon self energies. We find that
to describe the flow data of the FOPI Collaboration the strength of the vector
potential has to be reduced at high relative momentum or at high density such
that the Schr\"odinger- equivalent potential at normal nuclear density
decreases above 1 GeV relative kinetic energy and approaches zero above 2 GeV.
