Bump and Rebound settings

Discussion in 'General Discussion' started by GregoryLeo, Jun 1, 2017.

  1. Eddie Ellis

    Eddie Ellis Member

    Joined:
    Nov 6, 2017
    Ratings:
    +18 / 0 / -0
    In most cases with drivers who have been sim racing less than 2 years, this comes from too much brake. when a tire has too much brake it tends to slide or hop way before lockup. The classic brake skid is is really obvious and I'm sure you're not doing that. It is a subtle thing where you have just a bit more brake than traction. Using a little less brake pedal can often stop faster than pushing hard. On cars with huge brakes it is sometimes easier to drop the brake pressure from the 95% default to maybe 93 or even 90 if you don't have load cell pedals.
    On real life Formula open wheel cars brake traction is linked to air pressure on the wings. Some of the open wheel sim models now calculate this correctly, even though they didn't 10 years ago. So you can brake hard at 250 KPH but you have very little grip at 60 KPH and you need to trail off somewhere in between.
    There is also some ability to trail brake on some, but not all cars if your brake bias is correct and you brake very lightly. The best way to understand this is to take a car that responds a lot to weight transfer and try it. I suggest the 911 GT3R using brake bias from 57 to 51 two steps at a time. Do 2 laps then change the bias 2 clicks. This can be mapped to a button on this car so you don't have to warm tires in between.
    Of course a car that under-steers too much has a lower mid-corner speed and those setups will make you brake earlier.
     
  2. Eisprinzessin

    Eisprinzessin Well-Known Member

    Joined:
    Dec 7, 2015
    Ratings:
    +313 / 0 / -0
    Haha, i can see my wall ob the chart attachement :)
     
  3. Jynn

    Jynn Member

    Joined:
    Jun 7, 2015
    Ratings:
    +22 / 0 / -0
    old thread, but perfect for my question as I was looking to ask about rebound.
    @Pfalzdriver, said that to elimate oversteer on corner entry, increase front bum and/or rear rebound. Then someone else asked which value is softer and reply is that low value is softer for both. This makes sense for front bump for me, but not for rear rebound. If we take it that low values are soft for rear rebound than an extreme example would be:

    1 = shocks will extend almost instantaneously (should lead to more rear grip ie. eliminate oversteer on entry?)
    16 = shocks extend extremely slowly (rear outer tyre could leave the ground completely, leading to oversteer?)

    So is the above correct or is it the other way around?:confused:
     
  4. ChatCureuil

    ChatCureuil Well-Known Member

    Joined:
    Feb 10, 2017
    Ratings:
    +308 / 0 / -0
    I never remember how this bump/rebound works too. I imagine that "softer rebound" means it is slower to recover from the bump?
     
  5. Lucas dos Santos

    Lucas dos Santos Member

    Joined:
    Oct 2, 2017
    Ratings:
    +17 / 0 / -0
    Following video have some advices about suspension setup (dampers at 19:23):

     
    • Like Like x 1
    • Informative Informative x 1
  6. Christian Göpfert

    Christian Göpfert Topological Agitator Beta tester

    Joined:
    Apr 8, 2015
    Ratings:
    +2,228 / 0 / -0
    You are right. I would assume he just mixed those options up somehow. To counter excess oversteer on corner entry you can either stiffen the front or soften the rear.
    Explanation of the setting was correct tho, lower numbers mean less resistance inside the damper against the springs' force and hence faster up-/downward movement, higher numbers increase the resistance and slow the movement down.
     
    • Informative Informative x 1
  7. Jynn

    Jynn Member

    Joined:
    Jun 7, 2015
    Ratings:
    +22 / 0 / -0
    Thanks. Just so I'm crystal clear then, setting rear rebound to a lower number will help reduce entry oversteer?
     
  8. nate

    nate Well-Known Member Beta tester

    Joined:
    Jan 31, 2015
    Ratings:
    +874 / 0 / -0
    Dampers are probably the most complicated thing to setup on a race car, and to get them perfect for a specific track and all circumstances is near impossible. If you are oversteering in corners, I would first look at other things before the dampers. Such as aero balance, ride height, and roll bars.

    That said, this is the best setup guide I have found on the internet for describing what to do in certain scenarios - click here. Scroll down to section VII where it talks about corner oversteer.

    According to this, Pfalzdriver was correct that increasing rear rebound will help with entry oversteer. (edit: see below) Personally though, that is the last thing I would change. Lowering rear bump would be something I would do first. Rear rebound settings seem to help more with rotation in my experience, rather than oversteer. At least in my experience with some other games. In RR, I have never felt that the dampers play all that huge of a role, so again, I would look at other setup options first.
     
    • Agree Agree x 1
    Last edited: Aug 8, 2018
  9. Christian Göpfert

    Christian Göpfert Topological Agitator Beta tester

    Joined:
    Apr 8, 2015
    Ratings:
    +2,228 / 0 / -0
    That guide... I don't know if that should be trusted, even if it appears to be official. Sections V and VII kinda contradict each other from my pov.
    The majority of resources and guides I've read on suspension tuning suggest softening the rear in order to fight oversteer.*
    In my opinion, yes. :) Personally I wouldn't limit that to rebound only tho, and I agree with nate here, dampers/shocks are the last variable in a line of more influencial settings. Changing these is really only meant for fine tuning. So if your car is oversteering in general I'd also suggest to take a look at springs and ARBs, increasing front and/or softening the rear for both in order to increase rear grip (relative to the front) and thereby reducing the cars tendency to rotate.

    * Just a few sources:
    Unbenannt.JPG Unbenannt1.JPG Unbenannt2.JPG Unbenannt3.JPG Unbenannt4.JPG
    And I'll recommend this page once more:
    Code:
    http://www.rapid-racer.com/suspension-tuning.php#Damping:%20Bump%20and%20Rebound.
    I think it does a great job in explaining what dampers (and other components) do and how they influence driving characteristics.
     
    • Like Like x 1
    Last edited: Aug 8, 2018
  10. nate

    nate Well-Known Member Beta tester

    Joined:
    Jan 31, 2015
    Ratings:
    +874 / 0 / -0
    Yeah, thinking about this more, I think that BMW guide mixed up the rear dampers somehow. Making them softer, so decreasing them, should help with entry oversteer. So I think they might have mixed up the front and rear rebound dampers. Increasing the front should help correct some oversteer, while increasing the rear should exacerbate the issue.

    Some of the links Christian shared above are solid too. Though...

    rd setup contradiction.PNG

    Holy mother of bad English and contradictory descriptions :D
     
    • Agree Agree x 1
  11. Christian Göpfert

    Christian Göpfert Topological Agitator Beta tester

    Joined:
    Apr 8, 2015
    Ratings:
    +2,228 / 0 / -0
    Yeah, that racedepartment one probably also has a typo. If you look at the sentence right above that one you quoted, there they got it right and it is consistent. The one you quoted should say increase in regard to front rebound I guess..
     
    • Agree Agree x 1
  12. CheerfullyInsane

    CheerfullyInsane Well-Known Member

    Joined:
    Oct 24, 2015
    Ratings:
    +335 / 0 / -0
    Then again, if the car is going over steers, I think your bump-settings might be a minor issue at this point in the narrative. :D
     
  13. Jynn

    Jynn Member

    Joined:
    Jun 7, 2015
    Ratings:
    +22 / 0 / -0
    Thanks for clarification guys. Indeed I agree that it is for fine-tuning only and that is exactly what I am looking for. ie I've been doing the SRS week at Monza, using 0 wing and happy with ARB settings for all the corners except Ascari where I'm losing the rear a bit, but don't want to tighten up the car for the rest of the track.
     
  14. Rella

    Rella Well-Known Member

    Joined:
    Jan 31, 2015
    Ratings:
    +105 / 0 / -0
    Sure? I'm still struggling to understand how this is implemented in R3E. From my motorbike I know you close the damper fully (hardest) and from there on you count the clicks. So it would be completely the opposite.
     
  15. Alex Hodgkinson

    Alex Hodgkinson Sector3 Developer

    Joined:
    Jun 5, 2017
    Ratings:
    +1,184 / 0 / -0
    Here's a nice generalised set of rules I work to when tuning new cars:



    Corner entry

    Understeer:
    Rear rebound: Increase
    Front bump: Decrease

    Oversteer:
    Rear rebound: Decrease
    Front bump: Increase


    Mid corner
    Understeer:
    Front rebound: Decrease
    Front bump: Decrease
    Rear rebound: Increase
    Rear bump: Increase

    Oversteer:
    Front rebound: Increase
    Front bump: Increase
    Rear rebound: Decrease
    Rear bump: Decrease


    Corner exit
    Understeer:
    Rear bump: Increase
    Front rebound: Decrease

    Oversteer:
    Rear bump: Decrease
    Front rebound: increase
     
    • Like Like x 5
    • Informative Informative x 5
    • Useful Useful x 4
    Last edited: Aug 10, 2018
  16. Alex Hodgkinson

    Alex Hodgkinson Sector3 Developer

    Joined:
    Jun 5, 2017
    Ratings:
    +1,184 / 0 / -0
    1 is full soft, the highest number is fully hard. It's reversed to what you might experience on your bike, yes, but to most people it's most intuitive this way.
     
    • Informative Informative x 3
    • Like Like x 1
    • Agree Agree x 1
  17. Christian Göpfert

    Christian Göpfert Topological Agitator Beta tester

    Joined:
    Apr 8, 2015
    Ratings:
    +2,228 / 0 / -0
    It also depends on how the adjustment mechanism was (or had to be) constructed. On this page from Koni you can see that in example one and two adjusting clockwise increases firmness whereas for mechanism three it's the exact opposite and counter-clockwise increases firmness. So afaIk there's no hard rule irl, but like Alex said, in order to keep it simple it's always been the way he said in all SimBin/S3 titles. (probably even all isi-engine based games?)
     
  18. Rella

    Rella Well-Known Member

    Joined:
    Jan 31, 2015
    Ratings:
    +105 / 0 / -0
    Thanks for the clarification! I also found a confirmation of my theory in the manual of KW suspensions so it was confusing to me from the very beginning. I wouldn't have expected that in a game with a playerbase with such a profound technical knowledge. In any other game but not here ;)
     

    Attached Files:

  19. Nir Tal

    Nir Tal Member

    Joined:
    Aug 29, 2016
    Ratings:
    +24 / 0 / -0
    Thanks @Alex Hodgkinson for an official explanation for the way it works in R3E.
    As i know, most people consider the R3E damper setting as fast-damping while i conclude from what you wrote, its only slow-damping setting.

    i believe your last lines are typo - Corner exit-Oversteer - same as Corner exit-Understeer ?
    should it be like below ?
    Oversteer:
    Rear bump: Decrease
    Front rebound: Increase
     
    • Agree Agree x 1
  20. ChatCureuil

    ChatCureuil Well-Known Member

    Joined:
    Feb 10, 2017
    Ratings:
    +308 / 0 / -0
    Even by reading this page, I have doubts on my understanding, cause it seems it doesn't fit with my logic. :)

    Is it true?
    More Bump = less resistance from the damper (compress easier)
    More Rebound = Slower rebound (this is where my logic doesn't fit, I expect a faster one ^^)