Framerate speeding up and slowing down with RTX3090 but have great FPS

I have a frustrating problem with AMS2 that I can't seem to get my head around.
Although I have a super high end video card RTX3090 and a great frame rate 150+ fps vsync off and a steady 60 fps with it on. I can see the road and in particular the colored curbs speeding up and slowing down as I take corners. It really is off putting seeing this fluctuating road speed beneath me. It looks as if I'm not getting a smooth frame rate even though the stats on screen are rock steady. Nor do I get any hard disk activity so I don't expect Windows is doing any memory paging.
I've changed a heap of video settings including FOV, head movement all sorts of things and it still persists. I'm using the same video settings that I use in PC2 which runs perfectly (nor do I have any problems with ACC, AC, Race Room, BeamNG).
The only thing I can put it down to is my old age Logitech Formula Force wheel and the frequency it's running at, or being asked to be run at. I have the wheel setup as a custom controller in AMS2 and it works ok and I'm feeling all the forces.
I know in Content Manager when running AC I need to set the "Skip FFB steps" to 2.
I also believe there is a startup parameter for Project Cars 2 like -ffb <frequency rate> where you enter a frequency HZ figure. Does AMS2 use the same or similar parameter?

I really don't want to go out and buy a new wheel for this one game. Nor am I really sure it's a wheel problem. Any help would be appreciated.

 

The Custom Wheel profile sends FFB with ~400Hz-600Hz update rate. In theory the Logitech driver should rate limit this to lower levels, but if it really needs something like "Skip FFB Steps" in AC, then the driver is not doing it properly (or at all). In such case it could really slow down or even stall the input thread, @Domagoj Lovric
Don't know if it matters for the Madness Engine.

@ahpigsy
IMO much more appropriate profile for your type of wheel is the Legacy Wheel profile, which sends FFB with ~120Hz (IIRC from the last time I checked).

The Custom Wheel profile is suitable for DD wheels, etc., that really could benefit from the high FFB rate. Maybe Reiza could add some tips to help users choose the right profile.

 

@logos you are the man. Took your advice and setup a legacy wheel profile and my slow up/down track is gone. Only tried it on one track I know I can replicate it on, so will need to test it on other tracks too. But I was even able to turn Vsync off and ran a race with 20+ cars in a thunderstorm at 120+ fps and it ran perfectly. I can feel the Formula Vee slide, and I can catch it. I can be much more consistent, and race close to other AI something that was hard to do previously. Thank you so much.

My only problem now is a constant CTD when I enter a session if I start the game with my wheel connected. If I connect it after the game has started most the time it's ok.

 

@ahpigsy, Glad it worked.
For the CTD, if the bugsplat app appears after the CTD, just submit it to Reiza. I'm sure the bug report will be useful to them. Especially as they chase this issue.

 

Interesting information - thanks for the heads up.

...does anyone know which versions of the Logitech driver(s) this potentially effects ?