@Bram Hengeveld some the cars you need to increase the overall mz I believe it is to 34-40 bmanic posted a very good start up point for the ffb I'll try to find.
Bmanic
The most important parameter to check that it's set to 100 is the Force Feedback Strength parameter in the main controller menu. It defaults for many wheels at 75 and some wheels at 50 which is
completely wrong. Then make sure FFB damping saturation (the next parameter under FFB strength) is set to zero.
After this I suggest using Real Gain parameter (first value to 0.98, second to 0.1 and last value again t 0.98) unless you have a direct drive wheel (2000$+ wheel).. or even the Fanatec CSW v2.
Then finally
remove all smoothing in the car setup FFB menu. All cars default to 0.1 Fx Smoothing which is stupid.
Then I suggest setting the values for most cars like this (note that his is very subjective though. You need to adapt the FFB to your own type of driving):
Fx = 48
Fy = 44
Fz = 54
Mz = 100
Then the top parameter (master scale) to your preferred setting. I usually have it at around 34 to 40, depending on how heavy FFB I want.
Finally
one of the most important and one of
the most difficult to understand and tweakparameters is called Spindle Arm Angle (or just spindle arm). You can ONLY find it in each car's setup screen when you are NOT in the actual practice/qualifying/race session. So from the main menu go into car setup editing and you will find it as the last value. Many cars have this setting quite nicely set but some cars have it completely wrong. This setting is key to getting a proper feel of the forces
through the whole range of slip angles. If you set the value too low you'll have a very tightly centered wheel with little FFB once you cross over optimum slip angle. If you set the value too high the opposite happens.. the wheel is very light and "slow" in the middle and gets progressively stronger the more you turn the wheel. Set it just right and your wheel will be giving you amazing detail.
EDIT: One last note: My way of tweaking FFB is purely based on laptimes. I tweak until I get the ultimate consistent laptimes. I don't care at all about trying to get a wheel to feel "realistic" (which would be completely dead in a normal car) nor do I try to get it "heavy and bumpy". I just tweak it for ultimate
important physics information fidelity. I want to know exactly when I'm not at optimum grip levels. This is the only fairly OBJECTIVE way of tweaking FFB because I can directly measure it. I drive 5 laps around Silverstone with default FFB. Check my laptimes. I then tweak the FFB and drive 5 more laps then compare the laptimes. Did I do better? Did I do worse? It's like tweaking a car setup.
FFB can have a HUGE impact on your laptimes, especially if it is "wrongly set". It can truly work against you and make the car feel very odd if it's badly setup. But get it just right and you can vastly improve the laptimes and as an added bonus you wont be spinning and crashing as often either.