Do you use real feel by any chance Andrew?. Along with setup that is the biggest issue I have faced with this mod. I am currently using a mixture of LeoFFB and real feel. I cannot decide what to go with though as with just Leo's it feels ok as well. Real feel does give you a slight amount of judder but compared to initial settings it is like night and day.
Leo settings I got from rfactorcentral and they are:
23.0 Front Wheel lock angle, degrees (max deflection to one side from straight on)
0.873 Front wheel distance to centerline (half the front wheel track) in metres, from .pm file
1.470 Front axle distance to body reference point (about half the wheel base) in metres, from .pm file
0.5 Relative strength of FFB effects
9.0 Aligning moment curve shape / feeling of tyre losing grip. Lower numbers are duller, range 1.0 .. 10
0.99 Negative aligning moment parameter for high slip angles, range 0.0 ... 1.0
4.01 Slip angle where aligning moment reverses direction - typically between 8 and 15 degrees
2.5 Caster (dimetionless)
0.0 Camber ratio (not degrees!)
1.0 Road bumps feeling on the wheel
11500.0 maximum FFB force for stationary and low speed effects
10.0 stiffness of stationary wheels
1.5 wheel rubber hardness (1..5)
8.0 how quickly static forces drop off when rolling
Real Feel are my own that I have been working on
MaxForceAtSteeringRack=-3750.000000
SteeringDamper=11500.000000
FFBMixerRealFeelPercent=30.000000
SmoothingLevel=1
[ Force Feedback ]
FFB Device Type="1" // Type of FFB controller: 0=none 1=wheel, 2=stick/custom, 3=rumble pad.
FFB Effects Level="1" // Number of FFB effects to use: 0=No Effects, 1=Low, 2=Medium, 3=High, 4=Full, 5=Custom.
FFB Gain="0.98621" // Strength of Force Feedback effects. Range 0.0 to 1.0.
FFB Ignore Controllers="0" // Do not use FFB on: 1=controller1, 2=controller2, 4=controller3 (or add values to ignore multiple controllers)
FFB Throttle FX on steer axis="1" // 0 = Throttle effects on throttle axis, 1 = throttle effects on steering axis.
FFB Brake FX on steer axis="1" // 0 = Brake effects on brake axis, 1 = brake effects on steering axis.
FFB steer vibe freq mult="0.00000" // Controls frequency of steering vibration. Recommended: 0.5 to 1.0, 0.0 disables steering vibration.
FFB steer vibe zero magnitude="0.04000" // Magnitude of steering vibration at 0mph (reference point).
FFB steer vibe slope="0.00000" // Slope of line defining magnitude as a function of frequency (used with FFB steer vibe zero magnitude).
FFB steer vibe wave type="0" // Type of wave to use for vibe: 0=Sine, 1=Square, 2=Triangle, 3=Sawtooth up, 4=Sawtooth down.
FFB steer force prediction="0.00100" // Time into the future that force is predicted, to help counteract wheel latency (0.0 to disable)
FFB steer force max change="100.00000" // Maximum change per second based on current difference between calculated and applied force, to help avoid jerky behavior (values under 15 or so should reduce jerkiness, 100 disables)
FFB steer force neutral range="0.04500" // Max distance from center "neutral force" location where forces are reduced to help avoid oscillation (0.0 to disable)
FFB steer force neutral function="0.00000" // Function to apply near neutral force location, in order to tune out FFB "deadzone" but keeping oscillations in check: 0.0=original, 1.0=new
FFB steer force exponent="0.75000" // Steering force output "sensitivity". Range 0.0 to infinity. 0.0 to 1.0 = higher sensitivity, greater than 1.0 = lower sensitivity.
FFB steer force input max="-11500.00000" // Recommended: 11500 (-11500 if controller pulls in the wrong direction).
FFB steer force output max="1.70000" // Maximum force output of steering force, recommendation 0.8 to 2.0
FFB steer force grip function="0.40000" // Range 0.0 to 1.0 (previous hardcoded value was 1.0) - lower values will make steering force decrease LATER as front tire grip is lost - try 0.3
FFB steer force grip weight="0.55000" // Range 0.0 to 1.0, recommended: 0.4 to 0.9. How much weight is given to tire grip when calculating steering force.
FFB steer force grip factor="0.70000" // Range 0.0 to 1.0, recommended: 0.2 to 0.6. How much of a factor the front wheel grip is on the steering weight.
FFB steer front grip fract="0.00000" // Range 0.0 to 1.0 (previous hardcoded value was 0.0), additional effect of front grip loss on steering force
FFB steer update threshold="0.0000500000" // Amount of change required to update steer force/vibe (0.0 - 1.0). Lower values = steering force updated more frequently = lower frame rate.
FFB steer friction coefficient="-0.08793" // Coefficient to use for steering friction. Range: -1.0 to 1.0
FFB steer friction saturation="1.00000" // Saturation value to use for steering friction. Range: 0 - 1.0
FFB steer damper coefficient="0.17586" // Coefficient to use for steering damper. Range: -1.0 to 1.0
FFB steer damper saturation="1.00000" // Saturation value to use for steering damper. Range: 0 - 1.0
FFB throttle vibe freq mult="0.25000" // Scales actual engine frequency to force FFB vibration frequency. Suggested range: 0.10 to 0.50
FFB throttle vibe zero magnitude="0.09000" // Magnitude of engine vibration at 0rpm (reference point).
FFB throttle vibe slope="0.00000" // Slope of line defining magnitude as a function of frequency (used with FFB throttle vibe zero magnitude).
FFB throttle vibe wave type="0" // Type of wave to use for vibe: 0=Sine, 1=Square, 2=Triangle, 3=Sawtooth up, 4=Sawtooth down.
FFB throttle vibe update thresh="0.02000" // Amount of change required to update throttle vibe (0.0 - 1.0)
FFB brake vibe freq mult="0.85000" // Scales actual brake rotational frequency to force feedback vibration frequency.
FFB brake vibe zero magnitude="0.09000" // Magnitude of brake vibration at 0mph (reference point).
FFB brake vibe slope="0.00000" // Slope of line defining magnitude as a function of frequency (used with FFB brake vibe zero magnitude).
FFB brake vibe wave type="0" // Type of wave to use for vibe: 0=Sine, 1=Square, 2=Triangle, 3=Sawtooth up, 4=Sawtooth down.
FFB brake vibe update thresh="0.02000" // Amount of change required to update brake vibe (0.0 to 1.0)
FFB rumble strip magnitude="0.25000" // How strong the rumble strip rumble is. Range 0.0 to 1.0, 0.0 disables effect.
FFB rumble strip freq mult="0.50000" // Rumble stip frequency multiplier 1.0 = one rumble per wheel rev.
FFB rumble strip wave type="0" // Type of wave to use for vibe: 0=Sine, 1=Square, 2=Triangle, 3=Sawtooth up, 4=Sawtooth down.
FFB rumble strip pull factor="-0.62252" // How strongly wheel pulls right/left when running over a rumble strip. Suggested range: -1.5 to 1.5.
FFB rumble strip update thresh="0.07500" // Amount of change required to update rumble strip effect (0.0 - 1.0)
FFB jolt magnitude="1.00000" // How strong jolts from other cars (or walls) are. Suggested Range: -2.0 to 2.0.
My windows settings for my G25. :
70% Overall Effects Strength
0% Spring Effect Strength
0% Damper Effect Strength
Centering Spring enabled but set at 0%
Like I said I cannot decide what is right, but you can disable real feel by pressing Right Control Key + Numpad 2.