Curbs iracing parameter

Which parameter is responsible for the force generated at the curbs?

Rides in iR and curbs are tearing their hands :slight_smile:

TrueDrive Overall Strength

that’s not what I mean. because the overall strength is OK and I don’t want to diminish it. The problem appears on the curb that wants to tear off the hands :slight_smile:

Is there no parameter to reduce it?

You can reduce slew rate. I use 2.2, but you can go even lower if you’d like.
Also set Static Force Reduction to 0. This makes the differences between constant forces and small spikes smaller.

Hi, share your True Drive force setting %, and your iRacing max force slider setting in nm, then I can advise.


There is NO direct parameter in iRacing to reduce or increase curb feel… This is created entirely by the car Digital model and the Track Scan. so the way the curbs feel is dependent upon how the curbs were when they were scanned and the Set-up you have on the car.

The only way to change this is the overall at the wheel strength used (specific output).

You can alter slew, and friction to reduce the hits a bit but this will affect ALL aspects of FFB and not JUST the curb feel.

I would actually suggest that the best way to alter what you are feeing is within your car set-up in iRacing… You may be bottoming out the shock or the car which means you should try increasing Compression Damping or Overall Damping of the shock with possibly softer springs to absorb the hit and also possibly raising ride height. If you are running Fixed set-up then you will probably have to drive around it (i.e. use less curb)

I would approach this differently, going by the assumption OP is not complaining about the ripple-strips per se, rather the force hitting harsh curbs real hard.

So the best way would be to look at his current specific output, and then reduce the force /Amps in TD whilst reducing the force slider in iRacing, maintaining the same ratio.

This will limit what the servo can deliver to his hands, but care should be taken to avoid clipping in iRacing. So we still need his iRacing max force setting.

That is definitely an option as well @phillip.vanrensburg
The best method to do this would be:

#1 - Take note of your current iRacing Max Force Number
#2 - Get your current Specific output - divide 25Nm by the Current iRacing Max (CRM) force Number = 25/CRM = Specific output in .xxx form
#3 - Take the car you are driving out on the track and run a few laps generally hard but not running over the curbs too hard and preferably missing the ones causing issue.
#4 - click on the “auto” in iRacing - This will alter your max force to a NEW number.
#5 - Add approx 5Nm to that number to add a little bit of headroom in the telemetry.
#6 - find how many Nm you should output from your wheel base set from the New Max Force - Multiply the New MF x your specific output… (NMF x .xxx = New Nm)
#7 - find the new % to set in True Drive, divide New Nm x 25Nm = xx%

Process example - CURRENT Settings True Drive 100% 25Nm w/ iRacing at 70Nm Max Force

– 25 / 70 = .357 Specific Output
– Run Laps press auto, “auto” indicates 25Nm
– add 5Nm headroom = 30Nm
– 30 * .357 = 10.71Nm
– 10.71 / 25 = .4284 (42.8%)

AFTER Settings True Drive 42.8% 10.71Nm w/ iRacing at 30Nm Max Force

NOTE when doing this you may wish to put your Wheel Force in iRacing at a low number 10 and below as if you are doing this for a miata or another club level car you could get a bad “auto” setting due to the Wheel Force setting limiting the low point of the Max Force slider.

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Yes, basically my thoughts ^^

Just in my case, I will skip the auto-tuning thing as you know, and just do it all manually until it suits my needs. But anyway, hopefully this helps the OP, let’s see what he feedbacks after doing the adjustments.

I would generally skip it as well… but it is the easiest method to get a pretty good approximation of the output that is coming from the car… The only thing is different driving, Weather, Set-up, etc can change the number that comes out of it.

And of these, if you calibrate automatically by just doing “few laps” around a circuit, you will be getting bad results if you did not hit kerbs and lines in exactly the same way as if you were attacking the circuit and car.

Therefore the automatic strength just adds to the confusion as it creates so varied results.

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Thank you very much for your interest!
I thought that there was some magic slider that would limit these sudden jerks, but if it is not, I will live with it :wink:

w iR wheel force 25nm max force 46 nm

@Robson: See if this works a bit better, without compromising much on strength, it will only be slightly lower than what you’re running currently, but should feel ~20% lighter during heavy curb-strikes, which will be a bit easier on your hands, provided those curb-strikes were of a sufficient level to begin with:

Set True Drive to 80%, down from 100%
set iRacing maxForce slider to 37NM, down from 46.

This should give you a pretty decent torque-range without much clipping, anyway, if there is any clipping, it will be of such nature that you won’t feel it at all, as it will be short-duration sharp transients.

Let us know how it goes!

Well, yes, however if you are wanting to mitigate the curb shocks you would actually wish to miss the curbs so they don’t get added to the average forces output… When using “auto” you just have to be mindful of anything you do during those laps is being added as part of the average so If you drive very conservative your setting may be a little too low, if you drive really extreme your setting may be higher than wanted after the average…

iRacing also does a small amount of mitigation itself by only giving approx the 98th Percentile output as the auto so that some of the extreme harshness is clipped out. The only issue with this is the smoother the car telemetry output (either by car nature or the way you drive) the output can be low. This is why I suggest adding 5Nm to the number received by “auto”

You can also try to reduce the Torque bandwidth limit a bit there is really no need to have it higher than 2200Hz in Iracing. It only gives you a lot of unnecessary ripple and an overall unbalanced FFB.

Not in practice actually… though yes 2200Hz is a good number, running unlimited does offer some feel difference… Whether it is coming from the actual Hertz increase or the fact the processor no longer has to run a filter on the signal. the result in back to back testing for me is a more detailed output from the signal.