The REIZA DLC.....

Discussion in 'General Discussion' started by Dady Cairo, Oct 11, 2018.

  1. mantasisg

    mantasisg Registered

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    I don't remember if it was posted already, always lovely to watch videos from Niels explaining Formula Vee:

    https://www.youtube.com/watch?v=wJcwRyO5NP0&t

    Also check this:


    Literally unsafe at any speeds, and they killed Chevy Corvair at the states for things like these lol
     
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  2. softslider

    softslider Registered

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    In case of low yaw momentum car(easily spining car), trail braking adds more turning momentum than normal. Hence it's easy to get encouraged oversteer than expected. This doesn't mean it must be avoided. If you have enough resolution to control that kind of car, you can use it as required. But for beginner's practice, I don't recommend it.
     
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  3. Leynad

    Leynad Registered

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    The Vee is the most unstable on coasting, so trail-braking is IMO the 2nd best thing behind throttle input to keep the car stable, but the default is too crazy for my taste and my suggestions are full lock on the steering (24 deg), to have less steering input for corners and especially corrections and +1.0 toe in the rear (instead of +0.2) and 5 rear rebound (instead of 3) for stabilizing the rear and less oversteer out of corners. Especially the rebound helps a lot to get the weight back to neutral and softer rear-bump induce even more of it, if the (max) rebound isn't enough. But at some point you need the off-throttle oversteer to get the car around corners.

    By the way: Softer rear bump and stiffer rebound helps a lot to stabilize the Pro Mazda as well. Drives like a faster F4 here:D
     
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  4. mantasisg

    mantasisg Registered

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    Interesting about rear rebound, I used to think that if car has lift off oversteer, then reducing rebound stiffness is a way to go, to get tires being pressed towards surface more. Didn't thought about effect for wieght transfer from it.
     
  5. Leynad

    Leynad Registered

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    The slow bump/rebound is about weight transfer, the fast ones about road-bumps. The rebound is in both cases about getting back to a neutral position. If you want your desired transfer, just soften the bumps, but not automatically the rebounds.
     
  6. mantasisg

    mantasisg Registered

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    It must have been placebo when it worked to me all the times in the past :D Will investigate it.

    As for weight transfer, I don't doubt that it has such effect, but it mainly comes from suspension geometry I would suppose. But My knowledge is not perfect.
     
  7. Leynad

    Leynad Registered

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    I guess it's more about entry/apex/exit behavior and don't forget the toe-change. If the car oversteers generally, a softer rear suspension helps if it's spring- bump and/or rebound, but if you want to use the entry-oversteer and just need more stability towards the exit, a stiffer rear-rebound helps and it's better to keep the desired entry-behavior. That's why i'm saying, that softer rear-bumps (and springs) helps if it's generally too oversteering. I was using a more understeering setup before, but it's faster to use the off-throttle oversteer for entry and just deal with the mid-corner and exit-behavior than to make a car understeering in all aspects.

    The higher positive toe is inducing more mid-corner stability but for the sake of exit-oversteer behavior and the stiffer rear-rebound is dealing with that. So in the end you should get an excellent entry-, mid-corner and exit-handling.
     
    Last edited: Jul 13, 2019
  8. memoNo1

    memoNo1 Registered

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    THX for this input Sir.
     
  9. mantasisg

    mantasisg Registered

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    Sorry, I can't really agree, but perhaps due to my lack of knowledge, but if so I will learn. And I am still to try your suggestions.

    Softer rear bump should definitelly help to fight oversteer at acceleration, no doubt.

    But does rear positive toe really have such benefits ? I thought it is essentially only good for straight line stability, and maybe sharper turn in as it is essentially preloaded slip angle. I think slight negative toe should be better at rear because this way you basically reduce slip angle... I am not sure, it is always a trade-off. Of course acceleration vectors are also important, toes has always been big puzzle for me.[​IMG]

    As for rear rebound I don't think that it is in effect at all at corner exit, because at that phase rear end will be under compression, and that is when "bump" works. Unless it is very bumpy ride at the exit.

    Also does Fvee really suffer rear toe gain ? I thought what it suffer from is excessive rear camber loss under extension (as wheels drop down relatively to chassis), so you can try to fight that with more negative camber at the rear. i found out that, and then I found it out again as Niels mentioned it in his video.
     
  10. Patrick Schumacher

    Patrick Schumacher Registered

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    Thank you. First time I can partly handle this car :). Very welcome your instructions. :)
     
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  11. Andregee

    Andregee Registered

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    No. If you need more grip at he rear when accelerating out of the corner, you need to increase the slow rear bump. Why? When accelerating, the weight shifts to the rear. A higher slow bump at the rear means that the damper offers more resistance and therefore, due to the shift in weight, more pressure is applied more quickly to the tyre, which means more grip.Supporting you can increase the slow rebound in front. If it raises the front when accelerating, the increased resistance of the dampers slows down the spring out movement, whereby the front wheels spring out more slowly. This means that it takes longer for the front wheels to press on the road at maximum after weight shifting, which is why there is less grip at the front and more load on the rear axle during this time.For braking, the reverse applies accordingly. For more stability at the rear, reduce the slow rebound at the rear so that the springs can bounce faster and the tires can press faster with more pressure on the road while lifting or braking.. At the front, lower the slow bump, so that the dampers compress more before they pass the full pressure on to the tyres so that the maximum grip is applied in the front, which helps the rear axle to shift the weight.
     
  12. mantasisg

    mantasisg Registered

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    I guess it depends on car, so can't say that you are wrong, and I am right. I guess it is true if rear end is too light for a tire so it needs more load asap to have optimum load. I don't know if you mean optimum load by saying "maximum load", but if you actually mean maximum load" then we have to consider is it all mechanical load or it comes from aero, because it makes big difference.

    I think it makes sense to talk about tire load sensitivity and whole four wheels as a system at this point. Because of tire load sensitivity you want all tires to have as equal as possible pressure to the contact, thus equal loads on tires. Softer settings helps to suffer less from load sensitivity because it helps to keep more equal load distribution. Note that weight shift is not the same as loads shift, thanks to the dampers and springs and tires themselves because they are also machanicaly springs/dampers, roll bars (for lateral load transfer control). True that stiffer setting can help to extract more grip in shorter time, resulting in better response. But it will mean faster loads shift from one side to the other, which will result in worse overall grip. Because of this different tracks needs different setups, as some tracks has more sharp short small radius turns, and some tracks has more long large radius turns. Of course different elevations, bumps counts too... All this though becomes way less important as cars gain a lot of downforce. One of the reasons why downforce is so effective is that it helps to achieve more even tire loads by adding a lot more of it while it does not increase the weight of the vehicle obviously lol

    Sounds pretty much right about rear rebound to me there.
     
  13. Andregee

    Andregee Registered

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    No. Its does not depends on the car. This is valid in general because physics is valid for all vehicles equally


    I donĀ“t mean optimum or maximum load. Ultimately, the load is the same no matter how the dampers are adjusted. But for the moment when the weight transfer takes place, a higher slow bump offers more resistance, which is why the pressure is applied more directly to the tyre instead of first compressing the dampers more.

    All I'm saying is that you get more grip on the rear axle faster if the dampers offer more resistance during compression, This is also not a theory that I have sucked out of my fingers, I have taken a setup course with a real racing engineer and vehicle developer working in racing and whose competence is undisputed for me and also fully comprehensible

    You can't say that like that. It is ideal if you have an identical tyre load per axle, because a small wheel load difference per axle always offers more grip than a higher wheel load difference, which is why you should absolutely avoid the side tilt But you can not say that it is optimal to keep the tyre load the same on all 4 wheels, precisely because the driving condition is dynamic, the tyres are different widths on the axles, the weight distribution is not always 50:50 and the axle load varies depending on the driving condition. And there are driving conditions like acceleration where the wheels not only have to transmit lateral forces but also longitudinal forces, so it makes sense to have more load on the rear axle so that it can handle the increased forces.

    The dampers play a much smaller role in the lateral inclination than the stabilizers and springs in combination and finally the dampers are the last link in the chain with the least influence in this respect anyway, since the springs have a much stronger effect on stabilizers and the slow steps of the dampers only have an influence in the short moment of the weight shift. Therefore, the anti rollbars should be adapted to the lateral weight shift.
     
  14. mantasisg

    mantasisg Registered

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    I agree with most things, I think you are right.

    But I am still puzzled about some stuff, and I think you are also missing something. I think tire load sensitivity has to be understood better. It is very strange as it states that as tire gets higher load it does increase grip, but at decreasing rate. Also I think tires does not develop grip instantly because of rubber elastic properties, so I am pretty much sure that it is main reason why suspension stiffness is limited and at least some amount of compliance is necessary.
     
  15. David O'Reilly

    David O'Reilly Registered

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    I thought I was getting a sense of DeJa Vu in reading some of these posts here.
    We had a long conversation about the impacts of stiffer suspension (OK that time it was mainly springs) on handling.
    The same argument was being advanced by the same individual that by stiffening one end it somehow worked the tyre more effectively and increased grip.
    I even went as far as testing and sharing motec data to dis-prove the theory.
    https://forum.studio-397.com/index....rag-set-up-not-producing-good-lap-time.60394/

    I'm sorry but I don't agree.
    In my view and in my experience softening one end increases its grip. Therefore an oversteering issue is dealt with by increasing rear grip by softening the rear.
    In my opinion this belief comes from a misunderstanding of how springs and slow bump dampers effect the chassis control and handling.

    You are not somehow setting the springs and dampers against some universal constant force like against a building or gravity or something. Instead the chassis is in a constant state of movement. it is being moved by track undulations (fast bump dampers) and by the drivers inputs (slow bump dampers). It is wobbling around on the springs.
    When you stiffen one end it makes it less able to accept the chassis movement and weight transfer. Effectively the stiffer end is pushing the chassis away towards the other end more than it would have if it were softer.
    Then we can add the issue of compliance; the ability of the suspension (including the tyre) to absorb and deal with undulations while still remaining in useful contact and able to provide a great enough co-efficient of adhesion.

    There are limits of course and you can soften a setting so much that you move outside a useful range. That end gets squashed too easily, reaches the end of its travel and the required response is not there or is just too slow to respond. Damper settings that are too soft will also mean that end is bouncing around uncontrollably to the detriment of grip.
    But I will state that within a useful range softening the settings offers more grip at that end.

    In recent weeks I have dealt with a significant oversteer issue. It was fixed by reaching under the car and stiffening the front dampers and softening the rear dampers.
     
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  16. mantazzo

    mantazzo Registered

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    Well, on the Reiza DLC, I was suggested (on Discord) to put some bugs I found here (since I don't have an account in Reiza forums).
    I have tried the Imola 2001 track, and I have found some "collision" bugs:

    1) Pretty big one, IMO - right after Turn 6 (Villeneuve), on the right side of the track, the walls are not "solid":
    [​IMG]
    ^The barrier directly in front is not solid (fence too)
    [​IMG]
    [​IMG]
    (Additional note, if you go out of bounds, only "grass" is solid - the "asphalt" is not.

    2) After Turn 7 (Tosa), lefi side of the barriers are also not "solid":
    [​IMG]

    3) Turn 8 (Piratella), 2nd part - left side of the barriers are also not "solid":
    [​IMG]

    4) Turns 9-10 (Acque - Minerali) runoff zone on the left side - the grass alongside the barriers isn't a solid surface; you can fall through it OR leave your car hanging. However, it becomes solid where the asphalt escape road begins:
    [​IMG]
    [​IMG]
    Don't mind the engine smoke... lol
    [​IMG]
    Surface becomes solid right about there^ (Also, in the game I saw a pixel gap there, Reiza, pls fix)
    5) Between Turns 10 (Mineralli) and 11 (Variante Alta), one of the barriers (alongside the building) is not "solid":
    [​IMG]
    6) Lastly, one more offender is... Turn 10 (Mineralli), once again - this time, the inside walls/barriers (on the right side of the track) are not "solid":
    [​IMG]
    [​IMG]
    ^Look at me, I'm the Barrier now^

    Just wanted to share so that they could get fixed. :)
     
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  17. JRS

    JRS Registered

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    For no particular reason other than it caught my eye. I started watching and was like, "Hey those are those Brazilian Prototypes..." and then it was like, "Wow!".
     
  18. Patrick Schumacher

    Patrick Schumacher Registered

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    Keep burning...OMG those safety standards
     
  19. DaVeX

    DaVeX Registered

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    Lol those aren't safety standards at all, btw I just laughed hard after reading your comment due to your nick :D
     
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  20. Will Mazeo

    Will Mazeo Registered

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    Dont know what safety standards have to do with this, it's more like shity training, they weren't even pointing the fire extinger at the base of the fire, just throwing it out
     

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