Frame rate problem

Hi,

I have the UK version of the game and it runs only in 50 fps and stutter when the fps limiter is enabled.
If I disabled it and use instead nvidia inspector fps limiter to 60, I have 60 fps in the game, but the fps goes down to 55 fps often when I drive. I seems odd because whithout fps cap the game runs 500 fps.
There is something wrong. Any ideas ?

Here my pc specs
W10
i7 4770K
GTX1800TI
16GB Ram

I tested the game in vanilla with vsync turned on and the game run flawessly. But with the launcher I have frame rate issues.

Try some of the other methods for the built in Frame Limiter. Click on "Mod Settings" when selecting "Frame Limiter". There's currently 4 different methods "Waitable Timer", "Sleep", "Busy Wait" or "Sleep and Busy Wait"

Thank you for replying
It seems I fixed the issue.
As you suggested, I changed the method by selecting Busy Wait instead Waitable Timer. I also selected D3d9 in the list and I forced the vsync in Nvidia Inspector (becauseI had screen tearing).
Now it run smoothly.