iRacing FFB Configuration

The question of ‘How much FFB do you need on a wheel base?’ or ‘How do I configure my wheel base?’ are common questions on SimRacing Forums. People will often ask “What FFB do you run yours at?”

How much FFB do you need on a wheel base?

Some will buy a low-powered direct drive because they believe they don’t need the maximum force feedback given by a 25NM or greater device. Others will buy high powered units and run them at 50% because the force produced is too great.

There probably a sweet spot somewhere between the mid 10s and mid 20s but I wouldn’t recommend sub 10Nm devices and fear that those running their devices at 50% haven’t actually read a setup guide for IRacing FFB.

Rather than think about maximum torque we need to think about torque range.

Maximising Torque Range

In an ideal world we would map the Max Force to our Wheel Force with a one to one ratio but this isn’t possible so we look to get the ratio as close to 1:1 as we can. This is acheived in 5 steps:

  1. Setting some initial values
  2. Setting the Wheel Force to the Maxium Design Force given for the base.
  3. Drive laps and use the Auto Compute FFB Force to set Max Force for the car.
  4. Reduce intensity from the default of 0.5 if the FFB is too strong
  5. Add Damping & Smoothing to soften the Direct Drive

What we are trying to do is maximise the force feedback fidelity so that the subtle difference between tyre slippage and skidding can be felt at the same time as whether riding a kerb is unsettling the car or not can be felt. Balancing what your wheel base is able produce against what the car generates is a compromise. Give too much focus to the smaller vibrations and lots of clipping will occur at the higher end. Give space to the higher end and you’ll loose lower end detail.

Direct drives are naturally unforgiving. The connection between signal and wheel is direct where as in the real world there are ‘softening’ factors between the tyre contact patch and driver’s hands. So I think damping, smoothing and other tuning values are often overlooked.

Probably the most useful description can be found in the Granite Device Forum [4] but Sim Racing Cockpit (SRC)[3] also provides an excellent summary with charts such as this one below for the MX-5 driven using a SUC2 Pro.

Step 1 – Setting Initial Values

Firstly we set some initial values as per the following table.

Enable Force FeedbackThis should be ON!
Use Linear ModeiRacing says “Select “Use linear mode” if you are using a direct drive wheel, leaving this option off boosts smaller forces and can make lower end gear driven wheel such as the Logitech G27, G29, G920, and G923 feel more lively.” Driver61[2] says “Use Linear Mode (for Direct Drive only),” as does SimRacingSetup [7].
Reduce Force When ParkedPersonal preference – ON is a good option.
Intensity0.5 is the default. Reduce this if your wheel is too strong to turn. See Step 4
AutoThis can be used to set the Strength/Max Force to a value that does not cause clipping. It requires some test laps to be driven. If auto is greyed out then setting is same as the auto calculation. See Step 3.
Damping/SmoothingSee Step 5.
Min ForceSet ‘Min Force’ to 0.

Step 2 – Set the Wheel Force to the Maximum Design Force.

This should be set to the wheel manufacturer’s specifications which for the Simucube 2 Pro is 25nM. To prevent injury, DO NOT set the Wheel force to a value lower than the manufacturer’s specifications [1].

“If you are using a direct drive wheel, it is important to limit the wheel force to prevent potential injury. Wheel force should be set to the wheel manufacturer’s specifications. Some models’ specifications can be found below:”

Wheel BaseWheel Force
Thrustmaster TX, TMX, T2482 Nm
Logitech G25, G27, G29, G920, G923, DFGT2.2 Nm
Thrustmaster T300, T5004.4 Nm
Fanatec Club Sport V14.8 Nm
Fanatec CSL Elite6 Nm
Fanatec Club Sport V27 Nm
Moza R99 Nm
Logitech G Pro Racing Wheel11 Nm
Accuforce V1/V213 Nm
SimuCube 2 Pro25 Nm
Some common wheel base specs.

Its beyond this post but other factors that may affect FFB include slew rates and Stator Magnetic Saturation.

Step 3 – Auto Compute FFB Force to set Max Force

Every car you drive in iRacing has a maximum Wheel Force called Max Force in the UI.

If you see a “Strength” label instead of a “Max force” label click it and it will change to “Max Force”.

This is the maximum force produced by the car physics model and can be found in the SDK under the label ‘SteeringWheelMaxForceNm’. It is a unique value to each car that will also vary slightly per track.

CARTRACKMAX FORCE
Super Formula LightMonza73 NM
Example Auto FFB values from my driving.

The easiest way to calculate the Max Force for a car is to use the Auto Compute FFB Force option. To do this map the Auto Compute FFB Force to a key/button you can access while driving.

Drive a few laps and with the black box FFB option visible press the button. The peak force for the car should adjust accordingly.

Step 4 – Reducing the Intensity

If the combination of Step 2 and Step 3 has left the wheel feeling a bit heavy don’t be tempted to turn your Wheel Force down. Instead we can reduce the intensity on a car by car basis.

Introduced in 2023, Intensity controls how strong the force feedback feel will be when using the auto button in the F9 black box. Digging into the forum there is some clarification from iRacing Staff that 50% is the old normal and such the advice is to leave it at 50%.

A new “Intensity” slider has been added to the Driving Controls options screen. This slider replaces the “autoForceFactor” setting value, previously found in the “app.ini” file.

This controls how the Force Feedback auto button (found on the F9 black box) behaves. With the slider set to 50% it behaves as it did last season, giving you the maximum force that your wheel can produce. With the intensity slider set to 0% it will attempt to both lower the forces as well as give you some variation from car to car so cars with higher Force Feedback will feel heavier.

When you reduce the intensity you will see the Max Force increase – this is normal.

Step 5 – Taming the Direct Drive

Direct Drives are natually quite aggressive. This is because the direct drive lacks all the rubber bushes in the suspension and tire deformation isn’t something modelled very well in the simualtor. So lastly we have to add damping, smoothing and friction etc to replicate this. We can do this in iRacing or in any software that comes with the base.

If you are using True Drive Software you can look at the section below.

True Drive Software

This section is focused on the the Simucube software and the notes come from the SUC2 Pro User Manual and assume that you are in the advanced mode. I have canvased minimal opinons with those from GD and Revan (RN) coming from gPerformance[8]

SRS
[7]
GD
[8]
RN
[8]
DRDGMEExplained
Overall Strength60%100%71%60%100%For maximum “fidelity”, set your force feedback percentage in Truedrive / Fanatec’s properties manager or Fanalabs to 100% [3]
Steering Range900Probably 900
Bump Stop Feel and Range (Offset)Med
900
940Soft
900
Hard
900
Med
900 (0)
This is how the wheel resists being turned past its maximum steering angle. Its possible to change the strength of the stop, the angle and the ramp. (further information below)
Reconstruction Filter215652This predictive filter smooths the low update rate torque signal. Low filter values are reactive when the torque or direction changes quickly. Higher values are smoother but the torque peaks might overshoot. Filter can make the wheel feel more rubbery towards the higher values.
Torque bandwidth limitUnlimitedUnlimitedUnlimitedUnlimited1000UnlimitedThis is a low-pass filter that takes away some of the high frequency vibrations in the FFB signal. By setting lower values the signal will feel smoother but some detail will be lost.
Damping10%Off20%11%3%12%This dampens any fast torque effects coming from the simulator. The faster any change the more torque is generated in response. As simulators don’t always model tire deformation and rubber damping characteristics of car suspension accurately adding damping and friction is a good way to give realistic weight to the wheel and can reduce wheel oscillation and wobble.
Friction10%Off10%8%0%10%This is a constant torque that adds resistance to the wheel making it more difficult to turn. Alongside Damping it is appropriate to some sim/car combos. It can reduce wheel oscillation and wobble.
Inertia15%Off15%13%Off15%This gives the wheel more weight. The effect will resist any attempt to change the current rotation of the wheel.
Static Force ReductionOffOffOffOffOff5%In long corners this will reduce the the force while allowing other details to come through.
Slew Rate LimitOff0.95Off2.221.020.96This changes how quickly the wheel will respond. Off (the default) allows the wheel to perform at its maximum. Increasing the slew rate might make it feel less active.
Ultra Low Latency Mode7%5%13%15%20%10%This filter works on the connection between the PC and Wheel. Setting a higher value can prevent wheel oscillations when its not being held by the driver. It might also be possible to use this filter (reducing damping/friction) to get a stable non oscillating wheel.
Centre FrequencyDisabled6 Hz -2.0dB 0.5Disabled -25.5dB
0.1
Disabled
-0.1db
0.1
0
-25.5db
0
0
-25.5db
0

Bump Stop Feel and Range

This is how the wheel resists being turned past its maximum steering angle. Its possible to change the strength of the stop, the angle and the ramp.

Its possible to set the angle larger than the steering angle so in-game calibration can occur without hitting bump stops. Alternatively, setting a bump stop inside the angle can avoid less pleasant bump stops generated in game e.g. iRacing and its wildly oscillating bump stop force)

Direct Input Fine Tuning

Allows you to fine tune settings that games can utilise although Granite suggest not many titles (if any) do!

SourceDampingFrictionSpringSine
Wave
Square
Wave
Saw
Tooth
Triangle
Sim Racing Setup [7]0%0%100%100%100%100%100%
GheeD @ gPerformance [8]0%0%0%0%0%0%?
Revan @ gPerformance [8]0%0%0%0%0%0%0%
DR0%0%0%0%0%0%0%
DG100%100%100%100%100%100%100%

References

  1. iRacing – Controller Setup and Calibration
  2. Driver 61 – iRacing Force Feedback Setup Guide
  3. Sim Racing Cockpit – How to Find the Correct FFB / Torque Settings in iRacing
  4. Granite Devices – iRacing and Simucube 2
  5. iRacing Forum – Current state of FFB setting suggestions
  6. Simucube Documentation
  7. SimRacingSetup – iRacing Simucube Force Feedback Setting
  8. GPerformance Simucube Profiles
  9. VRS DirectForce Pro Wheel Base Settings

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