So I've been trying to play Grand Prix 2 on my main windows 8 PC, with Dosbox 0.74

I can set SVGA, maximum settings and framerate, it seems to run smoothly, processor occupancy is normally bellow 100% (in game press O), but, the game is rendered at a faster time than it should for some reason (1s in game takes less than 1s in reality), at least 20% faster, I mean based on how fast the car goes and reacts, but also the in game time measurement, I even compared side by side with my dos/win9x PC and it's different, 1s seems to take 1s, the old PC running natively even using minimum settings with 10% occupancy or all max at almost 100% seems to have the same time, like it should, I've checked against the clock and it looked correct, my main PC with dosbox runs to fast, I've tried changing core and the other CPU settings, but it runs very slow or like default, good but faster, any advice?