Low FPS! (World of Speed)

Of course, I understand that there is also a CBT and + is a game from mail, but still. Do I have one game dropping up to 20 frames? Especially in the corners. My system is not top-end, but it gives the Witcher at medium settings stably to play about 40 fps, GTA at medium-high - 40-50 fps, and here the mail miracle with graphics, which reminds me of GTA san andreas with mods to improve graphics, gives such drawdowns ...