Recently we proposed a new model describing rotationally inelastic collisions: the angular momentum and energy corrected sudden approximation (AECS) based on an effective angular momentum parameter l(c) = 2h limiting the possible amount of angular momentum transfer due to the restricted interaction time. In this work rotational energy transfer in N-2 induced by collisions with rare gases (He, Ne, Ar and Kr) is investigated with time-resolved CARS. We find it necessary to complement the AECS model with an energy gap term that can be formulated without additional model parameters. (C) 2003 Elsevier Science B.V. All rights reserved.