FFB - center feel of classic cars

Discussion in 'General Discussion' started by Esa Ahonen, Apr 21, 2021.

  1. Esa Ahonen

    Esa Ahonen Registered

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    Hi

    I recently upgraded to a dd wheelbase. All the S397 GT3/GTE cars feel pretty much perfect but I was surprised that some classic mod cars (eg. GT40, 917, 512S) have this sort of loose feeling in the center. And I don't mean that the FFB is light at the center. It feels more like there's play in the steering. A short area where there's no resistance at all and then "clank" when it starts to resist.

    I believe it was there all the time with my old wheel but now that steering of the new cars feels so nice and tight, it's more noticeable.

    Is there any way to get rid of this or is it built in the mod?
     
  2. benborp

    benborp Registered

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    This characteristic tends to be integral to the cars. There are several elements that combine to make the front suspension less dominant when it comes to steering input.

    The car is never going to carve a path precisely following your steering angle. Sensitivity to weight transfer and diff settings mean that the rear end is often more important in deciding where you will go. Steering works as an element of fine control or damper on the cars behaviour rather than an absolute determination of where you will end up on the track. Rather than telling the car where to go with the steering wheel you instead respond to what it is telling you and let it know that you either agree or disagree with its decision.

    This indistinct feeling around centre can be very useful in making these cars quick and being able to anticipate what they are about to do.
    When initiating a turn feeling the steering suddenly load up tells you when you have transferred a certain amount of the car's weight and it is going to more effectively pivot.
    Equally, the more precise feel for the loaded tyre means a more immediate sense of over rotation. Applying opposite lock as a correction becomes more instinctive and generally more routine exercise with a lot less drama.

    Using a DD should allow you to set-up and drive these cars more realistically. Generally they will need less steering input than you would expect and when corrections are needed, or you are really hustling the car, the more extreme steering inputs will be very rapid and almost automatic to the extent that it can feel like the car is steering itself.

    Edit to add: another thing about weight transfer with these cars is that it while it is a much more dominant factor in handling it is also much slower to take effect compared to a modern car. If your steering inputs get ahead of the car's attitude then the steering will feel even more vague and indistinct.
     
    Last edited: Apr 21, 2021
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  3. mantasisg

    mantasisg Registered

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    What gt40?

    Steering feel is a lot about friction, tire contact patch geometry, slip angle and how tire reacts to it, steering ratio, and last but not least - nominal force set up.
     
  4. Esa Ahonen

    Esa Ahonen Registered

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    I have no problem with driving them or recognizing weight transfer. Everything else about the FFB is fine but this small empty space in the middle of steering. It feels like the steering is not connected in the middle. I really don't believe that race car of even 60's or 70's had that much play in the steering. It doesn't affect driving but just feels unnatural.

    Edit: To be even more clear: you wrote about cornering etc. but I'm talking about the feel of the steering while going straight or doing the tiniest move to change the line on straights.
     
    Last edited: Apr 21, 2021
  5. Esa Ahonen

    Esa Ahonen Registered

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    GT40 Mk IV that can be found from internationalsimracing.com, I'm not aware of others.

    On my earlier wheels (CSL Elite and G25) this small characteristic of FFB was lost in the lack of small details overall. It's only now with the dd that it can be felt.
     
  6. benborp

    benborp Registered

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    There is feel there. But an aspect of making these cars work is exploiting this on/off switch in feel.

    With modern cars it is important to feel how much the front tyres have to offer with small changes of slip angle. These older GTs and prototypes that is unnecessary information. Laptime and tyre life aren't going to benefit from getting the front wheels to track within an nth of a degree. What is going to help is feeling when the front tyres have enough authority to govern the more dominant rear end. Which means a preference to greater feel for the extremes rather than detail.

    If the FFB was delivering that fine granular detail of the what the tyres were doing at lighter loads I wouldn't be able to transition effectively through the corner phases - the steering would be too heavy at the time I needed to get from one lock to the other.

    These lighter loads are another aspect of why this is an inherent trait in many of these cars. Modern GTs will be aero loaded at most cornering speeds and you will feel this force through the steering wheel. GTs and prototypes of that era generated much less down force (and several iterations of the Lola T70/Howston produce front end lift, which is disconcerting).

    Another aspect is that many rF2 tracks don't suit these cars, they are unnaturally flat, without the low frequency undulations or camber and profiles that give these softer suspensions something to work against.

    Some race cars can be decidedly sloppy when not pushed to their limits and wander terribly in a straight line. Cars of fifty years ago were a lot less refined and often had fairly loose and unpredictable behaviours.
     
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  7. benborp

    benborp Registered

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    Travelling in a straight line these cars have very little opportunity to create steering forces. They are generally moderately powerful with a rearwards weight balance and possibly generating front end lift. About the only thing generating steering forces will be the toe angle - and if that is negative that will be a fairly random and loose sensation (feeling the toe dragging the car from side to side on the straights was on of my first DD oooh! moments).
     
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  8. Comante

    Comante Registered

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    You may want to add some damping to simulate mechanical friction of steering linkage, otherwise, I think it's realistic that steering has a "loose zone" in the middle.
     
  9. mantasisg

    mantasisg Registered

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    That car is basically complete Howston G4 with 3D model of GT40 MK4 taken from somewhere. Usual rF2 modding business, no one will say anything, and happily pretend. Moders basically copy paste Howston G4 physics on many classics such as 917 or 911, and people love it, go figure, ok rant over.

    I am in general not a fan how Howston G4 tires are made, they are total slideshow. They doesn't really have much true grip, you have to skate it to perform. Not that those classic racecars wasn't about sliding, but not like that, not skating. The way grip works heavily contributes on steering feel.

    These cars has big tires, they also are pioneers of downforce. They have fast steering, and quite a bit of caster. Steering of these cars should be rather responsive. But comparing to modern racecars it is fair to expect more play, modern cars are way stiffer, tires are basically glue, steering is designed to be done with wrists unlike like with classic cars where you had to actually swing whole arm, casters are bigger because with powersteering there is no problem. These modern cars simply are "less play". Though they still add some extra skating in the sims, just for the appeal.
     
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  10. benborp

    benborp Registered

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    For my historic GT settings I have also increased the DD wheel's inertia to account for the larger wheels and tyres over the Formula cars of the period. This would also help give more feel of what was going on in that dead zone.
     
  11. Korva7

    Korva7 Registered

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    Are you using "FFB minimum torque"? That "clank" or step as the ffb comes in, might be caused by that. I don't use it with my dd.
    Wide no resistance area in the middle might be there because of the slow steering in older cars.
    You can manually change that steering wheel range to smaller angle if you want to try faster steering.
     

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