Shock wave radius evolution vs. explosion time t_bounce for different f_heat values. The simulations started with an iron core-collapse velocity of 1000 km s⁻¹, where t = 0 corresponds to shock wave formation. Dashed curves depict simulations employing coarse numerical grids, while solid lines correspond to higher-resolution implementations. The top and bottom panels show 15 M_⊙ and 60 M_⊙ ZAMS masses respectively, with initial velocities V_ini = 0 (left panels) and 300 km s⁻¹ (right panels). All models have a metallicity of 1/10 Z_⊙.