  We present new developments of the simple model of the central engine of GRB,
proposed recently. The model is based on minimal assumptions: some rotating
compact relativistic object at the center and stable perturbations of its
rotating gravitational field, described by Teukolsky Master Equation. We show
that using nonstandard polynomial solutions to the angular Teukolsky equation
we can describe the formation of collimated jets of various forms. Appearance
of imaginary part of the superradiance-like frequency is established for the
first time for pure vacuum black hole jet solutions of Teukolsky equation.
