Well Pacejka is the Sheldon Cooper of tyre physics (theoretical), and Scawen is the Leonard of tyre physics(applied), so just because it took Pacejka took 20 years to invent/discover new tyre modelling system, does not mean anyone applying/implementing the same existing formula (be it Pacejka or finite model analysis) will take 20 years. This is because I assume that, like in any programming venture, we won't be discovering new theories or inventing theories, but we will be implementing existing theories. I presume that is what is happening in the case of LFS tire-modelling as well.
That said, it is not going to be straight forward either. But the main challenge I think, and as Scawen mentioned is to reuse/implement/apply the existing theories and formulae in such a way that neither speed nor accuracy are compromised too much for each other But will it take 2 years or more? may be yes!
That said, it is not going to be straight forward either. But the main challenge I think, and as Scawen mentioned is to reuse/implement/apply the existing theories and formulae in such a way that neither speed nor accuracy are compromised too much for each other But will it take 2 years or more? may be yes!