  We consider a recently proposed scenario for the generation of primordial
cosmological perturbations, the so called Cosmological Slingshot scenario. We
firstly obtain a general expression for the Slingshot primordial power spectrum
which extends previous results by including a blue pre-bounce residual
contribution at large scales. Starting from this expression we numerically
compute the CMB temperature and polarization power spectra arising from the
Slingshot scenario and show that they excellently match the standard WMAP
3-years best-fit results. In particular, if the residual blue spectrum is far
above the largest WMAP observed scale, the Slingshot primordial spectrum fits
the data well by only fixing its amplitude and spectral index at the pivot
scale k_p=10^{-3}h x Mpc^{-1}. We finally show that all possible distinctive
Slingshot signatures in the CMB power spectra are confined to very low
multipoles and thus very hard to detect due to large cosmic variance dominated
error bars at these scales.
