  Recent observational results found a bend in the Tully-Fisher Relation in
such a way that low mass systems lay below the linear relation described by
more massive galaxies. We intend to investigate the origin of the observed
features in the stellar and baryonic Tully-Fisher relations and analyse the
role played by galactic outflows on their determination. Cosmological
hydrodynamical simulations which include Supernova feedback were performed in
order to follow the dynamical evolution of galaxies. We found that Supernova
feedback is a fundamental process in order to reproduce the observed trends in
the stellar Tully-Fisher relation. Simulated slow rotating systems tend to have
lower stellar masses than those predicted by the linear fit to the massive end
of the relation, consistently with observations. This feature is not present if
Supernova feedback is turned off. In the case of the baryonic Tully-Fisher
relation, we also detect a weaker tendency for smaller systems to lie below the
linear relation described by larger ones. This behaviour arises as a result of
the more efficient action of Supernovae in the regulation of the star formation
process and in the triggering of powerful galactic outflows in shallower
potential wells which may heat up and/or expel part of the gas reservoir.
