Brian Koponen

Programming and Tech Tips

Best Assetto Corsa Wheel Settings for Logitech G29 / G920

Assetto Corsa is best played with a force feedback wheel. As entry-level options, the Logitech G29 and G920 are fantastic, but the experience can be improved quite a bit by calibrating the wheel's force feedback response. When you are trying to drive at the limit of grip, every little bit of information transmitted through the wheel is important.

The motors in these wheels don't provide a linear response curve and have quite a large dead zone where light forces simply won't be felt at all. Calibrating your wheel goes a long way toward fixing both of these issues.

In this guide, I will show you how easy it is to calibrate your wheel and improve the driving feel on these cheaper wheels.

Downloads

You will need two programs to calibrate your wheel. First, download the WheelCheck app. This actually tests your wheel response.

Next, download LUT Generator for AC. You will need to sign up for a free account on Race Department to download this. This converts the data from WheelCheck into a file that Assetto Corsa can use.

Finally, download and install the in-game app FFBClip using the instructions on that page.

Calibration

Wheel Check

Wheel Check Settings
Wheel Check Settings

Wheel Check is a tool from iRacing used to calibrate your individual wheel. It's a very simple process:

  1. Run WheelCheck.
  2. Set the Max Count to 100.
  3. In Spring Force, select "Step Log 2 (linear force test)". This starts the calibration process.

Your wheel will start moving in increasingly larger motions. Don't touch the wheel during this process! This process compares the amount of force the computer sends to the wheel to how much the wheel actually moves.

Once it finishes, it creates a file called something like "log2 2019-04-25 10-00-02.csv" in your Documents folder. We will give this file to LUTGenerator in the next step.

LUT Generator

LUT Graph
LUT Graph

Run LUTGenerator and open the csv file that was just created by WheelCheck. This will create a Look Up Table (lut) file that Assetto Corsa can use to control the force feedback.

Save this file in Documents\Assetto Corsa\cfg as myLut.lut. When it finishes, it displays a graph that shows the raw data in red and the new curve in green. You can clearly see what a huge difference this will make. In my case, it is going to increase the forces at the low end and lower them in the middle to create an even force feedback response across the whole spectrum.

Assetto Corsa

To make Assetto Corsa use this file, open the Documents\Assetto Corsa\cfg\ff_post_process.ini file in Notepad and paste in the following text:

[HEADER]
VERSION=1
TYPE=LUT
ENABLED=1

[GAMMA]
VALUE=1

[LUT]
CURVE=myLut.lut

Content Manager

If you are using Content Manager instead of the default Assetto Corsa launcher, you no longer have to modify the ff_post_process.ini file. In Content Manager, go to Settings > Assetto Corsa > Controls > Force Feedback. Make sure “Enable FFB post-processing” is checked, then set the Mode to LUT and choose the myLut.lut file.

I recommend saving these settings as a preset, as I have had Assetto Corsa forget all the wheel bindings for no apparent reason in the past.

Wheel Settings

Now that the force feedback response has been calibrated, let's look at the available force feedback settings.

In G HUB:

Setting Value
Operating Range 900°
Sensitivity 50
Centering Spring Off

In Assetto Corsa:

Steering Settings

Setting Value
Gamma 1.00
Filter 0.00
Speed Sensitivity 0.00

Force Feedback Settings

Setting Value
Gain 100%
Filter 0%
Minimum Force 0%
Kerb Effect 60%
Road Effect 23%
Slip Effect 0%
ABS Effect 25%
Enhanced Understeer Effect Disabled
Half FFB Update Rate Disabled

Gain is the overall strength of all forces. Leave this at 100%. The FFBClip app will adjust the gain automatically as you drive.

Filter smooths out spikes in the force feedback. I don't find this necessary on these wheels.

Minimum Force raises the lightest forces to a level where they can be felt on these lower-end wheels. The LUT does this implicitly, so leave this at 0%.

Kerb Effect is the vibration felt when running over kerbs. I like to feel when I hit the kerbs, so I set this fairly strong.

Road Effect is the vibration felt based on the road surface. This can get annoying if set too high.

Slip Effect vibrates the wheel when you lose traction. I find this more distracting than anything, so I turn it off completely.

ABS Effect vibrates the wheel when ABS engages.

Enhanced Understeer Effect lightens the wheel to a higher degree during understeer. This feels unnatural to me, so I turn it off.

Half FFB Update Rate causes the Force Feedback calculations to run on every other frame. This could help your frame rate on older computers.

The Kerb, Road, Slip, ABS and Understeer effects are personal preference. They are designed to give you feedback about the car but are not things you would actually feel through a steering wheel.

FFB Clip

If you haven't already, download and install the in-game app FFBClip using the instructions on that page.

To get the most information from the wheel as possible, you want to make sure the game never sends more power to the wheel than it is capable of handling. This is called clipping. In the previous step, we set the Force Feedback Gain to 100%. Left as is, the forces would clip constantly, making the wheel feel terrible.

The FFBClip app automatically adjusts the gain level as you drive to maximize the forces and prevent clipping. During your first lap or two, you will notice the force feedback change as it finds the best setting. Adjust the FFBClip strength setting to your preference for a lighter or heavier feel.

The Dynamic Mode in the app maximizes the forces at all times. This raises the force feedback gain on the straights when forces are very light and lowers it in a corner when the forces are very high. I find this more distracting than helpful. You should try turning it on and off to see which you prefer.

What is all of this doing?

Force feedback is handled very much like an audio system. The louder the signal, the harder the wheel will turn. The game calculates the forces assuming that the wheel can “play back” the exact signal it gets, very much like a speaker. Very expensive direct drive wheels can do exactly that, letting you feel all the tiny little details that get lost on lesser equipment. Cheaper wheels have a very poor ability to accurately reproduce the signal, much like cheap speakers with very poor bass response.

When you calibrate the wheel and create the LUT file, you have a measurement of how the wheel actually responds to the signals it gets. In this way, the LUT acts like an equalizer on a stereo. Using the LUT, Assetto Corsa can adjust the signal levels sent to the wheel to make it move the intended amount. It’s a pretty clever solution to improve the feedback on cheaper wheels.

Continuing with the audio analogy, the FFBClip app with Dynamic Mode on is acting as a dynamic range compressor. It raises the quiet parts and lowers the louder parts to overcome the inherent limitations of these weaker wheels. With Dynamic Mode turned off, it is simply lowering the overall "volume" until the forces never clip, even when they are at their "loudest."

FFBClip isn't directly related to the LUT; you can use either one without the other, as they operate at different points in the calculation of the final force that is sent to the wheel. When used together, they provide a lot more useful information that you can actually feel through the wheel.

Conclusion

The first time I set this up, I couldn't believe how much better the wheel felt. You'll get a better feel for what the car is doing and, as such, may find it easier to catch slides and improve your lap times.

Let me know if you have any questions or comments.

Question or Comment?