iRacing FFB Discussion

[Blkout]

Starts here:

http://www.racedepartment.com/forum/threads/iracing-offers.53809/page-5#post-1686470

Can a mod please cut and edit that thread and move all of the FFB discussion on the last two pages to this thread for further discussion?

 

[Bakkster]

Referring to your question, I have no idea what might cause higher internal friction in a nicer wheel. You're right, it does seem a bit counter-intuitive, but given the results I can't think of a better explanation.

 

[Blkout]

Referring to your question, I have no idea what might cause higher internal friction in a nicer wheel. You're right, it does seem a bit counter-intuitive, but given the results I can't think of a better explanation.

Me either so I was just hoping to brainstorm some ideas and try to figure it out. No one is right or wrong I suppose, I just like good information and discussion.

 

[muscimol]

I think the "deadzone" is introduced on purpose to prevent the wheel oscilations on straights.
FFB API is pretty simple and at the same time it it pretty bad, you can read more here:
Why Force Feedback In Computer Simulators Does Not Work

The faster and stronger wheel, the harder to prevent oscilations because you don't have a command in FFB API like "move to position x", you can only set the direction and force, then you have to read the position and correct the result - the faster the wheel, the more probability that you will go past the desired position. Introducing the "deadzone" you make wheel artificially slower near the desired positions.

This is how the WheelCheck works - there is no possibility for any quirks. Just read the current wheel position, set the force and after a given time read the result position.

As for the feeling difference between G27 and Thrustmaster wheels - G27 doesn't start moving at all until 16-18% given force while Thrustmaster wheels start moving at 4% force although up to the 14% the response is very small - this is the reason, next to the lack of mechanical deadzone, that the wheels feel much more responsive than G27, but to achieve the linear response at the beginning you should give the comparable min force on both wheels.

Blkout, have you tested iRacing with different wheel forces and minimum FFB? You should definitely feel the huge difference on straights. Try the Spec Racer Ford on bumpy tracks like Lime Rock, Summit Point.

 

[Blkout]

I think the "deadzone" is introduced on purpose to prevent the wheel oscilations on straights.
FFB API is pretty simple and at the same time it it pretty bad, you can read more here:
Why Force Feedback In Computer Simulators Does Not Work

The faster and stronger wheel, the harder to prevent oscilations because you don't have a command in FFB API like "move to position x", you can only set the direction and force, then you have to read the position and correct the result - the faster the wheel, the more probability that you will go past the desired position. Introducing the "deadzone" you make wheel artificially slower near the desired positions.

This is how the WheelCheck works - there is no possibility for any quirks. Just read the current wheel position, set the force and after a given time read the result position.

As for the feeling difference between G27 and Thrustmaster wheels - G27 doesn't start moving at all until 16-18% given force while Thrustmaster wheels start moving at 4% force although up to the 14% the response is very small - this is the reason, next to the lack of mechanical deadzone, that the wheels feel much more responsive than G27, but to achieve the linear response at the beginning you should give the comparable min force on both wheels.

Blkout, have you tested iRacing with different wheel forces and minimum FFB? You should definitely feel the huge difference on straights. Try the Spec Racer Ford on bumpy tracks like Lime Rock, Summit Point.

First muscimol, thanks for continuing the discussion and being civil or not forcing your opinion. You've continued to try to be helpful and explain a lot so for that I do thank you.

I ran across a post last night by Clayton Macleod that says that Wheel Check program has been updated and now and to use the Min Force test to determine the minimum FFB in-game without having to do the Step 2 test to calculate it. Clayton said that his Fanatec GT3RS v2 is suggested to use 8% minimum FFB using this test. When I run the Min Force test on my TX, it tells me to use .5% minimum FFB if I don't change any other settings before running the test, if I check Always Update Forces and change Sleep (ms) to 10ms which is suggested for the T500, it gives me a minimum FFB of 2%.

I have used a lot of minimum FFB settings, depending on the car, anything above 8% can be quite violent.

 

[muscimol]

Graph from step2 log is much more informative because you can see the trend and you can estimate linear response.

Min Force test shows the value of the first wheel response and may be inacurate for Thrustmaster wheels which have some response at the beginning but it is dumpened a lot. I would suggest using proposed value by min force test when you're not using min force compression (FFBUseSimpleMinForce=1) but with the newer code (FFBUseSimpleMinForce=0) it is suggested to look at the step2 log. Eric Hudec, who wrote the WheelCheck, proposed min force 14% for the T500RS wheel for which I've posted the first graph although the min force test would suggest only 2%.

If you feel, that the response is too violent you should just lower the overall FFB force in iRacing settings (when you're setting some min force, all forces are boosted) but looking at graph from your it is clear for me that you should use at least 12% min force.