A computation model for nuclear reaction studies which is based upon a momentum dependent interaction between quasiparticles is extended to include collisions between the nucleons. The model is first used to examine the time scales involved in fragment formation at intermediate energies, both as a function of bombarding energy and impact parameter. The distribution of excitation energies and angular momenta of the reaction products is also investigated since the model possesses stable ground states. Several reactions are chosen as examples: Ar+C at 12A MeV, and Ca+Ca at 25A, 50A, and 100A MeV. The time scale for changes in mass distribution, etc., is discussed and the need for an afterburner scheme is established.