@Alex Hodgkinson This is the bug I've discussed with @Anthony Monteil, it seems it's more related with physics than sounds so I leave him alone. Between second 7 to 10, engine sound is fixed when speed is increasing from 160 to 185 km/h. We also noticed that there's something strange with NSU, the same effect (sound not evolving with speed increasing) but with fixed RPM like if the clutch was not fully engaging. I played with sequential shifter and auto-clutch but the other guy who noticed this problem used H Shifter with manual clutch. I also noticed this with the DTM 92' BMW, so I think it could be related with new clutch behavior on H shifter cars.