FFB Suggestion

[ozwheels]

@GTAndy36 Do you notice a difference now with the centering spring disabled?

 

[bleeder]

@GTAndy36 Do you notice a difference now with the centering spring disabled?

It's not disabled but SMS have it listed as a high priority fix now that they're properly aware of the issue (not sure what happened before but they didn't fix it). Hopefully soon

 

[ozwheels]

It's not disabled but SMS have it listed as a high priority fix now that they're properly aware of the issue (not sure what happened before but they didn't fix it). Hopefully soon

Do you feel the ffb is very light on turn in and a little loose on the straight like there's a dead zone that wasn't there before the patch?

 

[bleeder]

Do you feel the ffb is very light on turn in and a little loose on the straight like there's a dead zone that wasn't there before the patch?

I dunno. It definitely feels a bit different, can't quite put my finger on it. I'd say turning in requires more effort now though. Turned down the master scale a bit but haven't tested a lot really.

 

[Cocomoto]

The "buzzing" noise/feel is what ruin my experience with the game. With BMW M1 no matter what a i do, buzz still there with the 1.4 patch.

 

[lldantell]

Same here. I'm currently taking out each car to tune it's FFB settings, before i get further into the game and start tuning the suspension.

Basically: Master scale: don't up it too much, 26 is fine in most cases.
Fx: FFB when acc/braking
Fy: How heavy your wheel feels when cornering
Fz: How much FFB over bumps and kerbs
Mz: How much FFB when losing traction

Once you start playing around with those sliders, it has a great effect on all of the cars, and compensates for any 'lack off' or 'to much' effects on your particular wheel.

This comment helped me get a much smoother feel on my wheel. Now I have more control with the cars in this game.

 

[rocafella1978]

thought I would post this here for all you guys too, in webapp format:

http://pcars.oscarolim.pt/

 

[Glipizide78]

What's good numbers for steering brake and accel sensitivity for t300

 

[ozwheels]

What's good numbers for steering brake and accel sensitivity for t300

50

 

[Glipizide78]

50

Thanks

 

[Glipizide78]

Set ffb on wheel to 50 also...much better..at 100 something was popping and cracking sound, have already rma'd my base and don't want to send it back again

 

[tennenbaum]

I use the defaults but make sure to set the following:

Make sure the FFB strength slider in game is at 100%
The CSWv2 defaults but with SPR-Off and DPR-Off.


How much feedback you get through the wheel on curbs depends on a per car basis. The steering and suspension geometry as well as wheel alignment and tyre pressure must all have such an impact on the tyre's instability that it's easily affected by a curb. In other words the tyre must be able to easily push on the tie-rods.

- Soft tyres = lots of dampening of feedback
- Camber affects contact patch size and grip. If the tyre has grip it won't be easily upset even on a sawtooth curb
- Caster changes the angle of the Spindle/Tie-rod arm that is on the spindle. So it also affects the FFB.

There is a value in the per car FFB settings (under vehicle setup) that's called "Spindle Arm Angle". Playing around with that value can make a difference in how the FFB feels and reacts.



I am sure you are wondering... "but dude... when you go over a big sawtooth curb in real life you can definitely feel it through the wheel".
Yes, you can feel it through the wheel but where does it come from? When the tyres rise and fall onto and off of the curbs it produces a verticle impact. This impact is caught and dampened by your... tyres, springs and dampers.
However, the energy of the shock isn't being removed. The energy travels through the strut tower (which you can see under the hood or bonnet of the car) where the top of the shocks are mounted. It than goes through the metal of your entire chassis as a huge vibration.
Your seat is mounted to the floor pan, but your steering wheel is actually secured to the car's firewall. Often near your master brake cylinder. So the vibrations also go through that firewall as it's part of the chassis and reach up to your steering wheel.

Now if you ever drive on a stone road or even an off-road surface try to grab your wheel with one hand and your dash (also secured to the firewall) with the other hand. Now if you feel the vibrations same vibrations through the dash and your wheel, and as a third your seat, than those are vibrations that act upon the car vertically. It is not the energy that moves the wheels and pushes on the tie-rods which move the steering rack.


Back to pCARS. The FFB is actually simulating the steering rack movement by calculating the spindle's movement which is influenced by tyre physics.
My advice, if you really wish to feel the curbs in a proper manner, is that you invest in Simvibe and at least one Buttkicker tactile speaker (best 4 for chassis mode, giving you the vibration energy from all 4 points/struts of the car). The vibrations will than go through your desk, chair or best... rig. It will than travel in the same manner as it would in a real car, since your rig is your chassis.
Also if you're on console audio tactile is the only other option you have.


I am sure you might wonder why I give this advice and haven't opted at WMD during development to give us more 'curb feel'. This is due to how the energy travels in a car. Since the vibrations don't upset the steering movement (left/right), as explained earlier. It would be wrong to simulate something that it shouldn't be doing.

You see, the FFB signal is acting in exchange for the rack in the steering housing of a real car. The FFB motor actually acts as the pinion at the end of the steering shaft (to which your steering wheel is bolted) and is instructed to turn clockwise or anti-clockwise to move the steering wheel left or right.
The position sensor in your FFB wheel is sending back a signal to the physics engine that the pinion movement is or has been executed and the physics engine respositions the tyres in real time and recalculates things all over again.

Now if you add in unnecessary effects to the FFB signal, it also affects the car's phyics as it changes the steering angle of the car. In other words the car is being steered by the FFB, but the added effects would influence the angle of the tyres as well. This than causes the car to change direction, which upsets balance (even if very tiny) and so on.


Anyway, that's just my 2 cents. I do realize people have different wishes though, but I am a purist in this regard. So I always stuck to a balanced Fx Fy Fz and Mz force feedback settings in the game. You can get what you want via FFB, but it requires a bit of tinkering.
A FFB tweaking manual should be in the works, but I am not sure if it's 100% complete yet.


That said, this is from the wiki put together by the community: http://en.pcars.shoutwiki.com/wiki/Physics#I_can.E2.80.99t_feel_the_kerbs.3F

"I can’t feel the kerbs?
The kerbs are physically modelled, so if the kerb is rather flat in real life you won't feel much in the FFB."



Sorry, I know you might have wanted just settings but I felt that I should be complete so others learn as well.

Hi LogiForce,

i stumbled accross your great post here, and hoped you might help me with a question that puzzles me since a long time:

Does pCars' FFB system "weights" the Mz force as a part of the Fxyzm matrix in terms of being also one of those tireforces happening at the tire contact patch (i.e., e.g. acc. to Pacejka...), OR does Mz represent the torque at the (imaginary) steering axis, that is very depending on caster and KPI?

I'm aware that the scrub radius as a result of caster and kingpin inclination has an impact to the tireforce Mz at tire contact patch as well, but as far as i know the absolute Mz force (at tire patch) is much less strong than Mz torque forces resulting from force translations where mainly Fy and Fx translate into a torque caused by the geometry force effects due to the scrub radius.

In other words: When i dial in Mz settings in the in-car FFB matrix, does the FFB system computates and weights the "weak" Mz forces of contact tire patch, or the "strong" Mz forces that happen at the steering axis, eventually transformed trough rod, rack and pinion to the final torque a the steering wheel rack?

Very much looking forward to an answer, since this could explain some pCars FFB characteristics that i still can't fully "rationalize".

the question is in so far interesting too, because i always wondered on which basis the devs decided if Fz shall 'counteract' (pull into corner) or the other way round. my only guessing was so far, that they made it depending on positive or negative scrub radius, but my assumption doesn't correlate with what i feel when isolate Mz (by setting all other in car tire forces to zero).

 

[LogiForce]

Hi LogiForce,

i stumbled accross your great post here, and hoped you might help me with a question that puzzles me since a long time:

Does pCars' FFB system "weights" the Mz force as a part of the Fxyzm matrix in terms of being also one of those tireforces happening at the tire contact patch (i.e., e.g. acc. to Pacejka...), OR does Mz represent the torque at the (imaginary) steering axis, that is very depending on caster and KPI?

I'm aware that the scrub radius as a result of caster and kingpin inclination has an impact to the tireforce Mz at tire contact patch as well, but as far as i know the absolute Mz force (at tire patch) is much less strong than Mz torque forces resulting from force translations where mainly Fy and Fx translate into a torque caused by the geometry force effects due to the scrub radius.

In other words: When i dial in Mz settings in the in-car FFB matrix, does the FFB system computates and weights the "weak" Mz forces of contact tire patch, or the "strong" Mz forces that happen at the steering axis, eventually transformed trough rod, rack and pinion to the final torque a the steering wheel rack?

Very much looking forward to an answer, since this could explain some pCars FFB characteristics that i still can't fully "rationalize".

the question is in so far interesting too, because i always wondered on which basis the devs decided if Fz shall 'counteract' (pull into corner) or the other way round. my only guessing was so far, that they made it depending on positive or negative scrub radius, but my assumption doesn't correlate with what i feel when isolate Mz (by setting all other in car tire forces to zero).

Hi tennenbaum,

The quick answer is that it does do that. It's part of the tyre forces as below.

The thing is that if you add an inclination to the kingpin via caster angle, than you create a situation where you have to push or pull the tyre upwards. Cause at 0 degree caster, so a straight verticle kingpin angle, the tyre only has to rotate around the verticle kingpin that is placed on the inside of the tyre. How much around depends on the ET value of your rims, so the offset of the rims, plus the distance from the brake disc surface to the center of the kingpin.
So this offset will also play a roll in how much scrub/resistance you'll face at 0 degree caster and camber.
Now when you slant the kingpin by adding caster, your tyre still has to rotate around that kingpin but it also has to rotate upwards. This will add a dynamic camber while turning. Cause as the wheel rotates the outside of the tyre either gets raised off of the ground or gets pushed into the ground. This is also why when you turn some cars to full lock you'll see that the car raises up a bit. So if you ever wondered why a kart or a car does that... caster angle dynamically changing the camber angle is the answer.
Also angling the kingpin of course means that the contact patch will be moved 'backwards a bit'. In other words, it's further away from the bottom end of the kingpin. Other than directly beneath it when the kingpin is perfectly verticle.

A nice example of the raising of a car at full lock is in this following RC video...




Back to pCARS. So Mz represents the turning moment of the tyre around the kingpin, and thus is directly influenced by both caster and camber. Which is also part of the other forces. Cause the Fy (lateral force) obviously will also try to push the tyre away... up and around that angled kingpin.
Now Fx (directional force) will oppose Fy by nature as it wishes to keep the wheel moving in the direction of travel, while the lateral force tries to change the direction due to its side impacting nature.
Personally I like to keep these values equal because they oppose each other. If you start to mess with them, than basically you change the impact of the physics engine upon itself, cause the FFB motor directly changes the position of the wheels via the position sensor in your steering wheel. So anything that alters the weight of the tyre forces, alters the physics in a sense through the FFB wheel that feeds back into the game engine.

That said... you could basically say that Mz is kind of a volume knob for your caster, that increases or decreases the gain on Fx and Fy coming through. But again... I am of the opinion that all these forces should be in equilibrium with each other.
Fz is the normal force... so gravity and any other verticle forces that act upon the tyre. Gravity is of course also something that shouldn't be put out of whack.

So all in all, Mz Fxyz... leave them at equal levels for natural feedback from the game. If the game thus doesn't feel natural, it must be something in either the tyre physics or suspension geometry causing it to feel wrong.


Now that we know Mz and Fxyz... onto the next bit of your question. Why does the translation differ from the contact patch strength. Simple... leverage!

In the above you see a steering knuckle with a brake disc on it. The kingpin in this case exists out of two ball joints, an upper and lower ball joint.
Now the import bit is that metal rod in front of the camera. That's the tie-rod with the tie-rod end, which is attached to the steering arm. Yes, that same arm you can change the angle of in the FFB settings in the vehicle setup screen.

So basically the "arm angle" setting in the game let's you allow to change the construction of that steering knuckle, and to be precise... the angle of its steering arm. So it let's you alter the leverage you'll have on the tyre. Which will make it harder or easier to push the tyre up and around the angled kingpin due to caster settings.

As for calculating the 'weights'. Of course it does this, but it doesn't limit the dynamic range of the final result, but there are options to do that within the FFB settings as well.
The problem is that most consumer wheels don't have enough dynamic range in terms of torque from their FFB motors to deliver the right amounts of difference of 'heavy and light feel'. Which means that even when your wheel starts clipping at heavy load, you might feel too lightly when just driving casually.
Using this will let you alter the feel without changing the balance of Mz and Fxyz in an unfavorable way if necessary for your steering wheel.


I almost forgot your last question about Fz. I don't know what they see as positive or negative, but as Fz is the normal force (which includes gravity) than it means that it can't just "pull into a corner on its own".
What this means is that even though the forces from Mz and Fx and Fy don't come through, it doesn't mean that the physics don't calculate the change in suspension geometry based on car settings (caster, camber, toe). As well as the angle of your steering arm of course.
So these dynamic changes determin the pull you might feel. It's (I think) the weight of the car that tries to pull the tyre into a situation where it is running level with the ground again.
The thing is... you don't want it to pull into the corner. You want car to be pulled into a straight line direction. If the wheel pulls into the corner, the forces might go into negative. So if gravity increases the direction of which the steering wheel rotates by force is changed torwards steering lock instead of steering center.

So if you test Fz... it always has to return to the lowest center of gravity point. Cause remember... if you have Mz + Caster angle... the car will lift at lock and thus raise its center of gravity.


I hope this will answer some of your questions, cause I somewhere got lost myself in trying to answer them. Sorry



Important edit after testing

I just did some testing after brain storming the above and figuring out what's positive or negative, but it seems SMS has mixed up the positive and negative of the Fz (verticle acting normal force).


The following test was done with the BAC Mono at Bannochbrae (or however you spell it ):

I put Mz, Fx and Fy at 0 in the options and than set Fz to 200 (max).
When I turned the wheel with the car with the above settings I noticed something. It felt as if there was a 'hump' in the middle and the FFB rolled either off of it towards full lock on either the left or right side.
You've guessed it right. It's as if the FFB is inverted! Well... it is!

I will report this internally as an ex-WMD member. For now use FFBTweakers as PC users... console users will need to wait as you can't invert Mz or Fxyz via the in-game menu.

I used the following tweaker on my CSWv2 with default tuning menu settings (for 100, spr 100, dpr 100... etc).
There was no clipping, but there was no deadzone and the wheel felt properly heavy. Also I could properly feel the effect of humps and bumps at Bannochbrae. Plus opposite lock came on far more natural.

<?xml version="1.0" encoding="utf-8" ?>

<!-- Default force feedback tweakers. -->

<config>
    <value TopologyVersion="4" />

    <value SpindleMasterScale="0.26" />

    <value SpindleArm="5.0" />

    <value SpindleFxScale="1.0" />
    <value SpindleFxLoPass="0.0" />

    <value SpindleFyScale="1.0" />
    <value SpindleFyLoPass="0.0" />

    <value SpindleFzScale="-1.0" />
    <value SpindleFzLoPass="0.0" />

    <value SpindleMzScale="1.0" />
    <value SpindleMzLoPass="0.0" />

    <value SoPScale="0.0" />
   
    <value SoPLateral="0.0" />
    <value SoPDifferential="0.0" />
    <value SoPLoPass="0.0" />

    <value RelativeGain="0.0" />
    <value RelativeBleed="0.0" />
    <value RelativeClamp="0.0" />

    <value ArmScale="0.0" />
    <value ArmMass="0.0" />
    <value ArmStiffness="0.0" />
    <value ArmDamping="0.0" />

    <value GutScale="0.0" />
    <value GutLongScale="0.0" />
    <value GutMass="0.0" />
    <value GutStiffness="0.0" />
    <value GutDamping="0.0" />

    <value ScoopKnee="0.0" />
    <value ScoopReduction="0.0" />

    <value TightenCenterRange="0.0" />
    <value TightenCenterFalloff="0.0" />

    <value SoftClip="0.0" />
   
    <value BaseDrag="0.0" />
    <value BaseDragSqr="0.0" />
    <value BaseDragLoPass="0.0" />

    <value DisableDynamicSpring="true" />
    <value DisableLockSpring="false" />

    <value DisableScrub="true" />
    <value DisableThrottleVibe="true" />
    <value DisableJolt="true" />
    <value DisableWheelSpin="true" />
    <value DisableGearChange="true" />
    <value DisableRumbleStrip="true" />

</config>

 

[tennenbaum]

wow. first of all - thank you!

lots of food for thought.

gimme a bit time to zip on a coffee or two... ;-)

i did some tests too, but i don't want to draw conclusions without a proper second thought...

however, the 'inverse' Fz is definitely an issue. it could have made sense with cars that have a negative scrub radius, but even than, the effect (at default) would have been simply too strong. though, what could have been at least a little bit of a logical thing prooves irrelevant when you do tests by just using a vehicle that you know for sure that its scrub radius is positive: a kart!

testing it with a kart, the Fz force still counteracts, therefore pulls into the corner. ... which is definetly - by practical experience and theory - wrong. a weightshift (and that's best we can assume sms had in mind what Fz is supossed to do, besides curbs stuff...) to the left so the outer front tire of a kart while cornering to the right e.g. will cause (due to the positive scrub radius) a counter-clockwise torque at the steering wheel. cause the outer tire creates a stronger cornering force than the inner front tire due to the weight shift, therfore the positive scrub radius comes into effect... instead, pCars FFB turns the steering wheel clockwise (into the corner).
briefly: no matter if positive or negative scrub radius: Fz (due to weightshifts while cornering) leads either way to an 'inverse' steering wheel torgue... that doesn't make sense.

NB: first time now with the Radbul DLC car they "put" the direction of wheel-torque right... because the mazda radbul definitely has a positive scrub radius - as most other race cars as well anyway, ln so far the "direction" of FFB torque seems to be wrong for all the cars (besides the new Radbul).

if Fz really has this very fuzzy logic, the entire FFB system seems to become questionable. well, i better put that thought aside... :-)

about my Mz question: i did a simple test: i set the caster of the formula rookie first to minimum value, than to maximum value, while just setting Mz to 100 and Fcxz to zero. Mz didn't change, which seems to me the proof that the FFB system actually used the Mz forces of the tire contact patch. therefore Mz (which you weight of how much it is fed to the FFB system) is NOT the 'derived' torque caused by the goemetry of the steering rack.

NB: i did a counter-check test to make sure that changing the caster actually will be taken into computation by the FFB system: i set all forces to zero, but set Fy too 100 (or 200)... as expected, with higher caster values the FFB got stronger. that us correct (and gived us back a bit trust in sms' devs physic department ;-)

i'll come back to the spindle arm topic at a later time... the more i fiddling around with it the more i believe it doesnt work properly, beside the fact that i think the setting doesn't belong into the FFB section, but the tuning section, because by changing the angle, you definetly change the steering geometry mechanically,.. that is different than just weighting input forces...

however, i got the feeling, our both findings might complement each other in a nice way and can help to finally close some gaps of knowledge about the FFB - which still seem to exist, to my surprise.

 

[LogiForce]

wow. first of all - thank you!

lots of food for thought.

gimme a bit time to zip on a coffee or two... ;-)

i did some tests too, but i don't want to draw conclusions without a proper second thought...

however, the 'inverse' Fz is definitely an issue. it could have made sense with cars that have a negative scrub radius, but even than, the effect (at default) would have been simply too strong. though, what could have been at least a little bit of a logical thing prooves irrelevant when you do tests by just using a vehicle that you know for sure that its scrub radius is positive: a kart!

testing it with a kart, the Fz force still counteracts, therefore pulls into the corner. ... which is definetly - by practical experience and theory - wrong. a weightshift (and that's best we can assume sms had in mind what Fz is supossed to do, besides curbs stuff...) to the left so the outer front tire of a kart while cornering to the right e.g. will cause (due to the positive scrub radius) a counter-clockwise torque at the steering wheel. cause the outer tire creates a stronger cornering force than the inner front tire due to the weight shift, therfore the positive scrub radius comes into effect... instead, pCars FFB turns the steering wheel clockwise (into the corner).
briefly: no matter if positive or negative scrub radius: Fz (due to weightshifts while cornering) leads either way to an 'inverse' steering wheel torgue... that doesn't make sense.

NB: first time now with the Radbul DLC car they "put" the direction of wheel-torque right... because the mazda radbul definitely has a positive scrub radius - as most other race cars as well anyway, ln so far the "direction" of FFB torque seems to be wrong for all the cars (besides the new Radbul).

if Fz really has this very fuzzy logic, the entire FFB system seems to become questionable. well, i better put that thought aside... :-)

about my Mz question: i did a simple test: i set the caster of the formula rookie first to minimum value, than to maximum value, while just setting Mz to 100 and Fcxz to zero. Mz didn't change, which seems to me the proof that the FFB system actually used the Mz forces of the tire contact patch. therefore Mz (which you weight of how much it is fed to the FFB system) is NOT the 'derived' torque caused by the goemetry of the steering rack.

NB: i did a counter-check test to make sure that changing the caster actually will be taken into computation by the FFB system: i set all forces to zero, but set Fy too 100 (or 200)... as expected, with higher caster values the FFB got stronger. that us correct (and gived us back a bit trust in sms' devs physic department ;-)

i'll come back to the spindle arm topic at a later time... the more i fiddling around with it the more i believe it doesnt work properly, beside the fact that i think the setting doesn't belong into the FFB section, but the tuning section, because by changing the angle, you definetly change the steering geometry mechanically,.. that is different than just weighting input forces...

however, i got the feeling, our both findings might complement each other in a nice way and can help to finally close some gaps of knowledge about the FFB - which still seem to exist, to my surprise.

I spend all night testing the polarity of the Fz phase so to speak of ALL cars in pCARS 1. There are a few positive Fz cars in there, including both karts and all Toyota 86 models (except Scion Rocket Bunny). Radbul is positive as well.

Just check the list below, and I am sure it'll make more sense.
If only I knew why there are positive and negative desires on a per car basis. Well, something to dig in on the WMD side with both WMD members and SMS.


I'll try to do some more Mz and what have ya tests as well. Although the Frookie (short for Formula Rookie) is a bad test mule in my opinion. Try the Zonda R, which in my tests reacted heavily on the Fz test for sure.


Here are my results from Fz phase testing:

Desired Fz Phase of cars:

Kart 125cc = Positive
Kart 250cc = Positive
Alpine A450 = Negative
Ariel Atom 300 SC = Negative
Ariel Atom 500 V8 = Negative
Ariel Atom Mugen = Negative
Aston Martin DBR1-2 = Negative
Aston Martin DBR1/300 = Positive
Aston Martin Rapid S = Negative
Aston Martin V12 Vantage GT3E = Negative
Aston Martin V8 Vantage GT4 = Negative
Aston Martin V8 Vantage GTE = Negative
Audi 90 Quatro IMSA GTA = Negative
Audi A1 Quatro = Negative
Audi R18 TDI = Negative
Audi R18 e-tron Quatro = Negative
Audi R8 (LMP900) = Negative
Audi R8 LMS Ultra = Negative
Audi R8 V10 Plus = Negative
BAC Mono = Negative
BMW 1-series M Coupe = Negative
BMW 1-series M Coupe Stanceworks = Negative
BMW 2002 Stanceworks Edition = Negative
BMW 2002 Turbo = Negative
BMW 320 TC = Negative
BMW 320 Turbo Group 5 = Negative
BMW M1 Procar = Negative
BMW M3 E30 Group A = Negative
BMW M3 GT = Negative
BMW M3 GT4 = Negative
BMW V12 LMR = Negative
BMW Z3 GT3 = Negative
Bentley Continental GT3 = Negative
Bentley Speed 8 = Negative
Caper Monteray Stockcar = Negative
Caterham SP/300.R = Negative
Caterham Seven Classic = Negative
Caterham Superlight R500 = Negative
Ford Escort Mk1 RS1600 = Negative
Ford Falcon FG V8 Supercar = Negative
Ford Focus RS = Negative
Ford GT MkIV = Negative
Ford Mustang 2+2 Fastback = Positive
Ford Mustang BOSS 302R1 = Negative
Ford Mustang Cobra TransAm = Negative
Ford Mustang GT = Negative
Ford Sierra RS Cosworth Group A = Negative
Ford Zakspeed Capri Group 5 = Negative
Formula A = Negative
Formula B = Negative
Formula C = Negative
Formula Gulf 1000 = Negative
Formula Renault 3.5 = Negative
Formula Rookie = Negative
Gumpert Apollo S = Negative
Ginetta G40 Junior = Negative
Ginetta G55 GT3 = Negative
Ginetta G55 GT4 = Negative
KTM X-Bow R = Negative
Lotus Type 25 Climax = Negative
Lotus Type 38 Ford = Negative
Lotus Type 40 Ford = Negative
Lotus Type 49 Cosworth = Negative
Lotus Type 49C Cosworth = Negative
Lotus Type 51 = Negative
Lotus Type 72D Cosworth = Negative
Lotus Type 78 Cosworth = Negative
Lotus Type 98T Renault Turbo = Negative
Marek RP 219D LMP2 = Negative
Marek RP 339H LMP1 = Negative
Mazda MX-5 Radbul = Positive
McLaren 12C = Negative
McLaren 12C GT3 = Negative
McLaren F1 = Negative
McLaren F1 GTR Long Tail = Negative
McLaren P1 = Negative
Mercedes-Benz 190E 2.5-V16 Evolution2 DTM = Negative
Mercedes-Benz 300SEL 6.8 AMG = Negative
Mercedes-Benz 300SL (W194) = Positive
Mercedes-Benz A45 AMG = Negative
Mercedes-Benz AMG C-Coupe DTM = Negative
Mercedes-Benz CLK-LM = Negative
Mercedes-Benz SLS = Negative
Mercedes-Benz SLS GT3 = Negative
Mitsubishi Lancer Evolution IX FQ360 = Negative
Mitsubishi Lancer Evolution VI TMI = Negative
Mitsubishi Lancer Evolution X FQ400 = Negative
Oreca 03 Nissan = Negative
Pagani Huayra = Negative
Pagani Zonda Cinque Roadster = Negative
Pagani Zonda R = Negative
Palmer Jaguar JP-LM = Negative
RWD P20 LMP2 = Negative
RWD P30 LMP1 = Negative
Radical SRC Turbo = Negative
Radical SR3-RS = Negative
Radical SR8-RX = Negative
Renault Alpine A442B = Negative
Renault Clio Cup = Negative
Renault Megane R.S. 265 = Negative
Renault Megane R.S. 275 Trophy R = Negative
Renault Megane Trophy V6 = Negative
Renault Sport R.S. 01 = Negative
RUF CTR = Negative
RUF CTR3 = Negative
RUF CTR3 SMS-R = Negative
RUF RGT-8 = Negative
RUF RGT-8 GT3 = Negative
RUF Rt 12 R = Negative
Sauber C9 Mercedes-Benz = Negative
Scion FR-S = Positive
Scion FR-S Rocket Bunny Edition = Negative
Toyota 86 = Positive
Toyota GT86 = Positive
Toyota GT86 Rocket Bunny GT Edition = Positive
Toyota TS040 Hybrid = Negative
W Motors Lykan HyperSport = Negative

 

[tennenbaum]

hell of a work.

good hint with the scion, the 3 toyotas, mustang and aston martin, beside the 2 karts and the radbul.

are we saying the same thing?

before going on, did you consider my premisses to be valid?
Thus 1.) me assuming that the only criteria for the question which direction (phase) Fz must act can only be determined by the scrub radius. 2.) me assuming the weight shift (resulting in Fz) creating an outbound (positive) torque to the wheel, when scrub radius is positive, or an inbound (negative) torque, when scrub radius is negative. Both assumptions made due the rules of the book saying if one front wheel (of a RWD) gets more load (in terms of more friction or cornering force, or more braking) than the other front wheel, the wheel with more load pulls the steering (the rack) outbound when scrub radius radius is positive, or inwards when scrub radius is negative (called "spur-stabilisierend").
most modern road cars have negative scrub radius because they are easier to handle for non pros, in situations like aquaplaning, etc... on the other hand most real race cars have positive scrub radius as far as i know. mostly simply due to their wider tires and widened chassis. in so far the game seems to do wrong for most of the cars in the first place, imo. please correct me if i'm wrong with my assumption about race cars = positive scrub radius. i didn't do a check on that.

Now:

you say: "desired" Fz phase". does it mean, that

a.) cars that you detected as "positive" are the ones you think should have a positive Fz phase in terms of " they should NOT pull into the corner", while they actually do? Thus "positive" means the FFB acts wrong.

or

b.) cars that you detected as "positive" are the ones that you think they "desire" - in terms of deserve - positive Fy, due to your assumptions about their scrub radius?

i' m asking so meticulous ;-) because there seems to be a contradiction in your findings:

the karts do pull into the corner, thus the FFB puts out inverse (negative) Fz phase (resulting in negative steering wheel torque direction). Since t think karts do have doubtlessly a positive scrub radius, the game imo is wrong: Instead of putting out a negative (inverse) torque caused by Fz to the wheel, with karts the game should create a positive torque to the wheel, that pulls towards the outside of the corner. if that is what you consider to be true, too, than your mark "positive" stands for a car that is marked as car that the game's FFB acts wrong. According to a.).

But you mark the mazda radbul as "positive" too. Catch is: i think the radbul has for sure a positive scrub radius due to his wide tires, so with the radbul Fz must act positive. - Which Fz actually does. insofar the radbul FFB acts correct. (while with the karts it doesn't). Now that you marked the radbul also as "positive" the contradiction occurs...

puuuh, that topic got complicated. sorry for my lengthy post. i don't want to get too fixed on that matter, but afaik jack spade simply corrected (inversed) the radbul Fz (for pc users, a thing thats not possible for console users as you said) considering its FFB behavior as abnormal - which seems a bit nonchalantely to me in the light of what we discuss here...

the other reason why i got interested in the Fz topic is, that a lot of guys (kind of jack spade school thing) out there adjust their FFB in car settings with quite high Fz forces. which puzzles me, because by doing so they are not only using a force that might act wrong for most of the cars in the first place, but also counteracts with SoP Diff (which they use too) that is also weigth shift caused... in other words: i got the feeling they simply threw a lot of spices in a soup (at a time when the game's FFB was still often weird in general) that melted into something that might be "spicey" and everybody got used to it, but not necessarily logical and efficient... just a suspicion :-)

sidenote 1: i used the "frookie" because he has a wider range to change caster than most other cars. so the proof got more obvious, that the games Mz represents indeed the tire force, and not the derived torque resulting from caster and KPI ( king pin inclination) therefore scrub radius.

sidenote 2: my understanding of what you said in your first post is completely the same. also what you say about spinde arm (ackermann), but when i tested it the necessary steering force didn't change when i changed from 0 degree (0) to 45 degrees (4500). It'd be expected that 0 means less strength necessary to turn the wheel, while 4500 should lead to a higher steering force necessary, isn't it? well, given that sms didn't double the lenght of the arm at the same time, when setting it to 4500 ;-) or did you test oherwise?

EDIT:
on a second thought, it think the scrub radius with most race cars is so minimal that it's unlikely to be the reason for such strong weightshift effects expressed by Fz as pCars simulates. I guess sms took a different approach... but which ? ;-)