In this work, we develop a new species weighting scheme to reduce the computational effort associated with the study of freely expanding homogeneous condensation flows. The present work is an extension of our previous work[Kumar et al., AIAA Paper 2010-818 (2010)], in which, we developed CO2 condensation models in the statistical BGK framework to simulate the experimental data [Ramos et al., Phys. Rev. A72, 3204 (2005)] for stagnation pressures up to 5 bar. The present work is aimed at the development of a numerically efficient numerical scheme that will extend the range of applicability of the present condensation models to the more challenging flow regimes of higher stagnation pressures. The accuracy and efficiency of the new species weighting factor method is compared with simulations performed without weighting factors. Numerical results are found to be in agreement, with the new approach shown to significantly reduce the computational effort.