Discoveries with AC's FFB and the Thrustmaster TX 458

bmanic · Oct 28, 2015

I've played AC quite a lot now after the v1.3 patch (which I think was brilliant!) and finally decided to try and tackle the lackluster FFB feel of the game. First of all, the v1.3 patch already made the game feel a whole lot better but I was still getting very odd "rubber band" feel in the wheel which caused all the cars to feel very similar to each other. I may have found the reason for this though and I'm unsure of if it's a bug or a design decision by Kunos.

The key to fixing the weird rubber band feel is in the "Auto-Center Settings" in the Thrustmaster Control Panel. You have to tick the "by the wheel" dot and set the actual value to zero %. It defaults to "by the game (recommended)" setting and for some odd reason it feels like Kunos is using auto-centering FFB (basically spring FFB) in reverse. So that when you turn the wheel, the FFB motor in the wheel helps to reduce the drag of the physical wheel (similar to Fanatec drift modes) whereas in all other games the auto-center FFB feature is mainly used to center the wheel for menus.

It is possible that it's a bug in either the game or in the Thrustmaster driver.

Anyhow, once I got rid of this I started tinkering with the experimental FFB settings in the assetto_corsa.ini file and these are the settings I have so far. They may look really strange but anybody who is dissatisfied with AC's FFB has nothing to lose by trying them.

My Thrustmaster TX 458 control panel settings:

Overall strength of all forces = 68
Constant = 100
Periodic = 80
Spring = 45
Damper = 0

Auto-Center Settings = "by the wheel 0%" (this one is critical!)

.. and in the Assetto_Corsa.ini I've set the following:

[FORCE_FEEDBACK]
FF_SKIP_STEPS=0 ; Physics engine steps to skip in order to accomodate wheels with lower FF input buffer

[FF_EXPERIMENTAL]
ENABLE_GYRO=1
DAMPER_MIN_LEVEL=0.05
DAMPER_GAIN=2.1 ; Set to 0 for Logitech g920

Then within the game controller preferences I have FFB strength at 100, filtering at zero and minimum force at 6. Most cars I set to around 85% FFB strength but some of the high downforce cars needs to be set lower to avoid heavy clipping during mid- to high-speed cornering.

EDIT: Road, Kerb and Slip effects within the game are all set to zero. Steering is set to fully linear and wheel rotation to whatever the calibration wizard sets it at when I hold my wheel 90 degrees. In my case this means steering lock becomes 887. Pedals are set to default. I have the crappy stock TX pedals.

So far these settings make the game a lot more enjoyable for me. I just hope Kunos gives us a few more tools to properly "shape" the FFB signal within a linear range for our consumer wheels. Right now the heavy cornering forces are too high in relation to the important mid/low forces during moderate slip angles. Basically the FFB signals map into the wrong range of the TX 458 which has a sort of bell curve at the 80-100% FFB strength of the wheel. This means I'd need to shape this range a bit to get actual linear behavior which in turn would help differentiate between small slip angle details while cornering.

EDIT: updated my thrustmaster control panel settings.

Ryan · Oct 29, 2015

Question for you @bmanic to complete the ensemble:

What settings are you using for Kerb Effects, Road Effects, Slip Effects, Steering Settings, and Pedal Settings (also which pedals do you have)?

I can't say I've ever been grossly dissatisfied with the FFB in AC since I got my TX but I probably just don't know any better. I just tried your settings and things felt a lot weaker than I'm accustomed to but as you said, there was more detail. I guess your settings are more like wine to my whiskey? Is this what FFB is "supposed" to feel like? I did manage to take a set of soft tires for much further than I ever have before with very consistent times (and broke my personal best with the stock setup) so it may be worth getting used to...

If I did want a bit more punch would you say turning the Thrustmaster settings to say 75%? Perhaps up to the 80% mark that you had mentioned?

bmanic · Oct 29, 2015

Ah yes, sorry forgot about the additional FFB effects. I have them all set to zero. So, kerb, slip, road and such are all on zero.

Yes, if you want stronger FFB then simply bump up the Thrustmaster control panel overall strength to your liking. However, keep in mind that the TX wheel (and most likely T300 as well) gets progressively more non-linear once you go past about 75% strength which means you'll have a much harder time getting consistent FFB and right now there's no way to combat this in AC (in pCars for instance you can use the Scoop parameter to combat this high FFB strength non-linearity as it re-maps the forces to compensate for the odd bell shape that happens at the top of the FFB range of the Thrustmaster wheels). You can find out the linearity of your wheel with the WheelCheck.exe program (originally posted on iRacing forums but you can find links to it with some googling).

Steering settings are fully linear and pedal settings I have as they were by default (using the calibration wizard). I've only got the crappy stock TX pedals, unfortunately.

My FFB tweaks in all the simulators are always done with laptimes in mind. I never tweak FFB by feel alone. I always drive many laps around a "reference" circuit (in AC it is Mugello or Silverstone) then do a few FFB tweaks and drive again approximately 10 laps and compare my laptimes. If the laptimes become better and more consistent then I know my FFB tweaks are improving things. In my opinion this is the only correct way of tweaking FFB. The reason why I say this is because when driving with a direct drive wheel, everything becomes easier and you'll automatically get better laptimes just by "listening" to the wheel. Unfortunately these rather mediocre consumer wheels that most of us can afford just can't compete so you need to severely massage the FFB information sent to the wheel to get similar benefits.