Logitech G27 Force Feedback FFB Assetto Corsa - A.S way

WheelCheck.. FCM tool Lut Converter.. FFBClip App .. tried them all . . and wasted alot of time testing pretty much every guide out there.. till i was like.. ok . time to think.. and not replicate things like a parot.. and VIO LA.. never been so good before. Let me know how it works out for ya. Enjoy !

G27 Owners .. simplicity is DEVINE!

The confusion and frustration of the G27 not being a good wheel and the pain to set it up correctly.. its your christmas today.. try.. and thank me later.
Without going into once again confusing technical details.. straight forward.

1)
120% in oder to eliminated the "deadzone behaviour" or interfacing bug of the G27 completly - just by doing that

40% - 55% dampening, because otherwise your wheel will turn loose if car isn´t rolling. Standing rubbers still provide resistance on the steering wheel. ( i have to in 70% as the not roll resistance should be higher than the slow roll one)

6bKypZO.jpg



2)

Under C:\Users\UserName\Documents\Assetto Corsa\cfg in the controls.ini file edit like this:

[STEER]
JOY=0
AXLE=0
SCALE=1
LOCK=855
FF_GAIN=1
FILTER_FF=0.6
STEER_GAMMA=1
STEER_FILTER=0
SPEED_SENSITIVITY=0

MIN=0
MAX=0
DEBOUNCING_MS=5

[FF_TWEAKS]

MIN_FF=0
CENTER_BOOST_GAIN=0
CENTER_BOOST_RANGE=0


[FF_ENHANCEMENT] (or 0 them out.. and do by car individually)
CURBS=0.15
ROAD=0.05
SLIPS=0.1
ABS=0.05


[FF_ENHANCEMENT_2]
UNDERSTEER=1


3)


Create a file Linear.txt file in the C:\Users\UserName\Documents\Assetto Corsa\cfg folder, open it with notepad or editor and add:

0.00|0.00
0.02|0.02
0.04|0.04
0.06|0.06
0.08|0.08
0.10|0.10
0.12|0.12
0.14|0.14
0.16|0.16
0.18|0.18
0.20|0.20
0.22|0.22
0.24|0.24
0.26|0.26
0.28|0.28
0.30|0.30
0.32|0.32
0.34|0.34
0.36|0.36
0.38|0.38
0.40|0.40
0.42|0.42
0.44|0.44
0.46|0.46
0.48|0.48
0.50|0.50
0.52|0.52
0.54|0.54
0.56|0.56
0.58|0.58
0.60|0.60
0.62|0.62
0.64|0.64
0.66|0.66
0.68|0.68
0.70|0.70
0.72|0.72
0.74|0.74
0.76|0.76
0.78|0.78
0.80|0.80
0.82|0.82
0.84|0.84
0.86|0.86
0.88|0.88
0.90|0.90
0.92|0.92
0.94|0.94
0.96|0.96
0.98|0.98
1.00|1.00

There you go, you wanted a linear G27.. there you have it now.

After that, rename the Linear.txt file to " Linear.lut" (lima, utha, tango) and save it.

4)

Open the ff_post_process.ini file and change it to:

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

[GAMMA]
VALUE=1

[LUT]
CURVE=Linear.lut

5)


Open the assetto_corsa.ini file under :\Steam\steamapps\common\assettocorsa\system\cfg and make sure the following part look like this

[FORCE_FEEDBACK]
FF_SKIP_STEPS=1

[FF_EXPERIMENTAL]
ENABLE_GYRO=0
DAMPER_MIN_LEVEL=0.0
DAMPER_GAIN=1.0

6)


ingame should now look like this:

C4qscXj.jpg



Here you can also use 60-70% as GAIN Main and Filter ZERO !!



 
Last edited:
@=A.S= , this lut that you write has ZERO influence. As i said , you multiply all values by 1.
0.00|0.00
0.01|0.01
0.02|0.02
0.03|0.03
0.04|0.04
0.05|0.05
0.06|0.06
0.07|0.07
0.08|0.08
0.09|0.09
0.10|0.10
0.12|0.12
0.14|0.14
0.16|0.16
0.18|0.18
0.20|0.20
0.22|0.22
0.24|0.24
0.26|0.26
0.28|0.28
0.30|0.30
0.32|0.32
0.34|0.34
0.36|0.36
0.38|0.38
0.40|0.40
0.42|0.42
0.44|0.44
0.46|0.46
0.48|0.48
0.50|0.50
0.52|0.52
0.54|0.54
0.56|0.56
0.58|0.58
0.60|0.60
0.62|0.62
0.64|0.64
0.66|0.66
0.68|0.68
0.70|0.70
0.72|0.72
0.74|0.74
0.76|0.76
0.78|0.78
0.80|0.80
0.82|0.82
0.84|0.84
0.86|0.86
0.88|0.88
0.90|0.90
0.92|0.92
0.94|0.94
0.96|0.96
0.98|0.98
1.00|1.00
 
edit :

Your wheel with 120 gain is like this (blue line):

attachment.php


Yes you have zero dead zone, but huge non linear behavior.
Then you multiply with 1:1 lut file and you have as a result the EXACTLY THE SAME BLUE LINE.

What you need is a lut file that reads X and gives Y, in order to fix this line and make it more linear.
But why bother and do that with 120% gain and lut as long as you will have the SAME result with 100% gain and another lut?
 
Try this then

tXvMyuE.jpg



but you CAN NOT eliminated the natural "lack of force" deadzone of the G27 by ingame settings only... if your OVERALL STRENGTH is not able to cover the deadzone area. I know, the box "allow game to override g27 values" is checked..but it does not work on the overall VOLTAGE - FORCE.
 
edit :
Yes you have zero dead zone, but huge non linear behavior.
Don't want to interfere your discussion, just my 2 cents to this:
I like the non linear behavior of the G27. In my opinion Logitech did this to give the user the "feel" of linearity because the motors just can't deliver true linearity as a DD.
When I created a lut that makes the G27 behavior "linear" it just felt absolutely awful in my hands. Very very little forces while driving normal but kerbs broke my hands :roflmao:
I think except of the deadzone both Kunos and Logitech did a very very good job with their default settings :)
 
G27 has hardware interface (electronics) and is unable at 100% to deliver enough voltage (force) .. so it can cover the dead-zone area .and start exactly at 0x,0y. Known "flaw" of that device. Measured and proven many times.

PS: exactly Rasmus, but it has more to do with magnetism - electrical - force output curves of electric motors..if we want to go into details.
 
Last edited:
When I created a lut that makes the G27 behavior "linear" it just felt absolutely awful in my hands<<

becaue it will not work with 100% :) you need to give the device enough strength to START at 0 FIRST.. and THEN "tame it down" ( "lut it right" )..and make it linear.. (see my last pic above). mechanical true forces VS profiling << but this cant work. if the device ITSELF cant even start at 0.
 
When I created a lut that makes the G27 behavior "linear" it just felt absolutely awful in my hands<<

becaue it will not work with 100% :) you need to give the device enough strenght to START at 0.. and THEN tame it down..and make it linear.. (see my last pic above). mechanical true forces VS profiling << but this cant work. if the device ITSELF cant even start at 0.
Yep, I tried different strengths in the profiler but it didn't change that I didn't like the feeling of the "true linearity".
To test it I took a spin at the skidpad mod track and slowly went faster while driving in circles. The force (and the ffb output) steadily raised but what I felt in my hands was not "linear" at all!

But again: each to their own. Wheelcheck, Lut Generator etc really helped my on my way to my personal, favorite settings so I'm very thankful for the work of others! :)
 
Well all i say that it doesn't really matter which gain profiler will use as the post process will make them all linear.

This is my wheel in various gains:
Capture.jpg


Now, why bother to fix the 110% which is the worst at the 1st place?
See how much more linear is the 95% gain. 110% is super abnormal.
Why introduce a complex lut file that will only add cpu load and maybe lag?

This is my approach. I decided to go simple.
Took the 95% and fixed it:

Capture2.jpg


my lut :

LUT
0|0.18
0.52|0.4
0.87|0.92
1.0|1.0

simple right?

result :

Capture3.jpg


The result is EXACTLY the same if i try to make the 120% or the 95% linear as the outcome will be exactly the same 100% linear line.
But i believe that the most elegant approach is the most efficient.

My G27 with this lut, 5% slip effect , 0% all effects and 30% damping for stationary weight and slimax manager pro for harware lock, feels better than ever.

Cheers
 
@Jim

The result is EXACTLY the same if i try to make the 120% or the 95% linear as the outcome will be exactly the same 100% linear line.

yes and NO! .. :) theoratically YES.. but practically NO. JUST because you "order" AC to give more force at the dead-zone area.. doesn´´t mean.. AC is able to give enough voltage (overall strength) to the electric motors.

I say it again ! INGAME settings (not matter what racing sim) DO NOT ALTER THE logitech "overall strength" aka voltage source of the G27.
 
The "overall strength" slider delivers the peak (max) voltage source for the elec. motor. but under 120% the volatage is too low to cover the deadzone accuratly.

Therefore i started at 120% and later smoothed it (lut-ed) it out to my personal liking.

Guys its that simple omg..is that hard to explain.
 
@Jim

The result is EXACTLY the same if i try to make the 120% or the 95% linear as the outcome will be exactly the same 100% linear line.

yes and NO! .. :) theoratically YES.. but practically NO. JUST because you "order" AC to give more force at the dead-zone area.. doesn´´t mean.. AC is able to give enough voltage (overall strength) to the electric motors.

I say it again ! INGAME settings (not matter what racing sim) DO NOT ALTER THE logitech "overall strength" aka voltage source of the G27.
Did you measured this on the actual G27 motor?
Because I think if you double all values in the LUT (200%), the MAXIMUM force output you feel in your hands actually gets higher. (normal slider won't work because of the clipping algorithm).

Also the wheel will oscillate like crazy.
So a lut that doubles all values should be the same as 200% in the profiler. More or less because of different algorithms.

But it seems I have to try this to know if I'm right :p
 
@Jim

The result is EXACTLY the same if i try to make the 120% or the 95% linear as the outcome will be exactly the same 100% linear line.

yes and NO! .. :) theoratically YES.. but practically NO. JUST because you "order" AC to give more force at the dead-zone area.. doesn´´t mean.. AC is able to give enough voltage (overall strength) to the electric motors.

I say it again ! INGAME settings (not matter what racing sim) DO NOT ALTER THE logitech "overall strength" aka voltage source of the G27.

I did test them all obviously so when i say "exactly the same" , mean practically.
I couldn't feel any difference at all.
 
Simulation > delivers data to the wheel.. how much force is used ! If 5Volts is 100% .. that that is the range the simulation can play with

Device >> at 100% or 5Volts lets say .as example..is unable to provice enough force to cover the deadzone area !!! therfore 5.7 volts or 120% is needed to FIX THE DEVICE first.. so the simulation later can send data and utilize the device in its hole bandwith accuratly.
 
Simulation > delivers data to the wheel.. how much force is used ! If 5Volts is 100% .. that that is the range the simulation can play with

Device >> at 100% or 5Volts lets say .as example..is unable to provice enough force to cover the deadzone area !!! therfore 5.7 volts or 120% is needed to FIX THE DEVICE first.. so the simulation later can send data and utilize the device in its hole bandwith accuratly.
Are you sure that the slider in the profiler actually has influence on the voltages in that direct way?
I think the profiler slider is just another software slider and does NOT limit the maximum. It just takes what it gets.
So if you put your lut to 200% on all values you will reach the same as 200% in the profiler.

So in my theory, it's all just software. At what point you modify the forces to your liking doesn't matter. The profiler slider does not limit the overall range or anything else.

But not sure, I will test it...
 
Yes.. ingame settings (pcars, ac, rf2) have no impact on the overall strength slider (meaning the max voltage available to the elec. motors). Confirm. Overall Strength slider sets a hardware specific max voltage limiter.

btw

Linearity: must be given in the device response.. in order to be able to convert simulation data accurately (linear (as provided by physics engine of sim -and not falsified)

NON-linearity (or non linear drive feeling): is only determined and that feel comes only by the car physics itself. As you know. a real car wheel turns more or less "linear" (strong) depending on your physics regimes (that is what good simulations simulate good").

effect <> and cause .. seperate analysis.
 
In other words.. you can never know, if your simulation has good physics and FFB data... if your wheel is "non linear" and fake-scripted and "compensated", "tweaked" something something output. Ever drove direct (linear) drive force feedback steering system?

Edit: not to forget.. servo-drive care.. direct wheel cars.. true mechanical conversion of specific cars..i highly highly doubt any simulator as that (wheel to wheel force conversion due to mechanics) even implemented.
 
Last edited:
In other words.. you can never know, if your simulation has good physics and FFB data... if your wheel is "non linear" and fake-scripted and "compensated", "tweaked" something something output. Ever drove direct (linear) drive force feedback steering system?
Sadly not but as you stated before:
We are slowly reaching the point where we are going to flip all tables and build our own haha.

I will test if the profiler slider really limits the max force output! Thanks for the reply :)
 
for example.. for shits and giggle i tried this now

Blue is 120% G27
Red is "mirrored" counter LUT

Green is linear average line

55sYnDn.jpg


Horrible.. feels like "sheet". Totally weak sluppy wheel.

Normally. it should average.. but no. .because not the green line, but the RED line (the lut) is the ACTUAL determinator of what force is send to wheel. (therefore me using a linear lut :) )
 

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