Add Dedicated Smoothness Filter instead of only Reconstruction Filter to True Drive for SC2

I would like to see a dedicated smoothness filter, ideally 0.000-100.000% and high precision. I’d like to try disabling Reconstruction Filter and just experimenting with a Smoothing filter.

Currently we only have Reconstruction Filter to help with actual smoothing but, judging by the User Guide, it seems like there’s some complex logic going on under the hood that complicates getting a good result.

Spending many years on SimCommander for AccuForce, I learned a dedicated smoothing filter was absolutely critical for getting a good feeling on that wheel.

Because there’s only a few options with Reconstruction, and it seems to be doing much more than just smoothing, it results in cases of having too much or too little of one thing conflicting with too much or too little of another thing, but you can’t adjust them since they’re all bundled with the Reconstruction Filter.

PS. Anyone ever thought of opening up a developer mode to end-users who want to tweak really low-level stuff like this and, for example, whatever else goes into Reconstruction Filters?

Thanks for considering.

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I agree, there are times where changing the Reconstruction Filter by one has too dramatic an effect on details (SC1 in my case).

SimCommander offers a range of Smoothing up to 300% (iirc). Granted, such level of variability in range is a lot but, it does make for superb fine-tuning of detailed effects as related to road texture, tire-scrub, etc., while still providing an excellent overall rubbery quality in ffb.

Some titles offer users a way to boost certain ffb-effects but, others have limited options and rely on greater adjustment within the wheel-driver settings.

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Signal smoothing is available in Simucube 2 at the moment via the reconstruction filter,the slew rate limit filter, and also (for now) the torque bandwidth limit filter.

We are not adding a signal averaging filter that would add lag. Other suggestions are welcome, though. But as majority of the people that want to try adjustments to parameters are still not engineers, we will prefer to have “off/low/medium/high” -style adjustments in the future.

Please do not dumb it down even further!


We’ve pretty much decided to keep the current level of adjustments, even if it makes the device more hard to use and more difficult to get right settings for the majority. The upcoming online profiles are a good starting point to get turn-key settings for those that do not want to have to spend any time to make adjustments, rather than just start driving with good feeling FFB.

However, when we are hopefully soon starting to add new filters,we will need to be extra careful when adding their parameters and settings ranges.

  • We already have a support overhead of people setting up filter settings that do not work well together, causing all kinds of numb feel issues, extra oscillations, etc. Those people just write to our support (or the resellers support) causing us to have to do non-productive work to point them out to forums or giving them some settings that should work well.
  • To reduce this, we need to have setting options that work well and that do not have strange interactions with other filters. This directly causes us to really think about what we can add…
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Making the current parameters or working method of the Reconstruction Filter available, would not be possible for us to disclose - someone would copy it right away.

However, we are adding a “secret filter development parameters” window where the expert users would input manually some parameters for some new filters we are developing, in the style of

  1. test firmware version X has a filter A in development with parameters 1 and 2 that can be adjusted in the test dialog
  2. we would monitor the accompanied forum thread and decide whether the filter works well enough and what settings people like
  3. test firmware version Y has filter A added officially with those off/low/medium/high options and filter B in development with parameters 1 and 2 that can be adjusted in the test dialog.

… and so on.


Yep, same issue SimXperience ran up against, luckily they had the dedicated smoothing filter.

Ya, this might work. It’s not exactly the idea but it’s possibly an improvement.

I wonder if you could avoid support trouble by gatekeeping the expert settings with a checkbox that says people can only use the support forum for support if they want to enable expert settings? Then you could add all kinds of nice things.

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is there a place where i can find detailed explanations of what each parameter changes in ffb/feeling?

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The User Guide is the main place I’d think but it doesn’t talk about how each parameter “feels”. I agree that’s one of the greatest benefits of software parameter descriptions that are usually missed.

I’m going to try to fill in “feeling” for some params on my blog about the SC2P here:


Looks promising!

As we all know, the ffb signal of iracing is at 60hz, that is, every 16.6ms it sends a signal.
I would calculate the slew rate limit by dividing TD Overall force by 16.6

In a sim with ffb Signal of 100hz, Overall force divided by 10

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Wrong on so many levels. True Drive overall force strength has nothing to do with it. You are wildly mixing terms…

Iracing can send a signal of, for example 0 Nm at one point, and in the next update, 30 Nm. This is e.g. a direct hit to a wall that causes 100% force, when the in-game FFB slider is at 30 Nm level. The game-commanded slew rate of this signal is then (30 Nm - 0 Nm) / 0.0166 s = 1807 Nm / s = 1,807 Nm/ms.

But even this math is pretty academic, and I fail to see why these types of calculations and scales need to even thought about. Maybe we should just remove the visible Nm/ms value from slew rate limit, rename it to “reaction speed” with 0-100% scale or something.

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Whatever you do please don’t simplify what’s already there.

I have found when tuning that even up to a thousandth of a percent change in ffb tuning can be felt through the wheel.

If you must do 0-100% then do 0.000-100.000%.

SimXperience had this discussioin, as well, about what precision to display in the interface and they ended up allowing a drag method to do more precise selections.


Being there doing that, dont lose your time here…

I can’t understand how iRacing can send a 30Nm Signal if my TD Overall force is at 3.2Nm (example), really I can’t.
Must be sending a command like telling TrueDrive “go to 100% force”
Ence my conclusion about SlewRate being relative to True Drive force.

To anyone Who wants to try, just put TD Overall force at 3.2Nm and SlewRate at 0.20, it must be just enough to Drive on iRacing any formula rims in any SC2