Release Stunt Car Remake

Played in Win10. Hit F9 to increase the frame rate - at what I assume is 60fps the game is unplayably fast. Dropping the framerate makes the game slower, but obviously the framrate is crap :)

Any chance of a fix for this?
It's always done that even on the Pandora. I just run it as fast as I can but without making it too hard for me, although on a couple of tracks my twitch motors come to the fore and I can play better at superfast that at thinking speed.
I had created a branch to try have smooth framerate, but for now, it's not working correctly. The physics engine is linked to the framerate (it's an old game, and the core of the remoke come from reverse engeneering the original, so the same limites applied), and break the link is tricky...