Don't exagerate, S1 has no chance against new cars even on Nordschleife.
Of course there is always a possibility to make gearing for such circuit but why when all other stages are normal? WTCC S2000 had top speed around 240 km/h with similar engine specification as rally S2000 when it was needed (Monza for example). Just let it be like it is. It's circuit. It's beautiful one but no rally stage.