  We present results on the effect of the stiffness of the equation of state on
the dynamical bar-mode instability in rapidly rotating polytropic models of
neutron stars in full General Relativity. We determine the change in the
threshold for the emergence of the instability for a range of the adiabatic
$\Gamma$ index from 2.0 to 3.0, including two values chosen to mimic more
realistic equations of state at high densities.
