Suspension Theroies R-Us

Discussion in 'GT6 Tuning' started by IamWSPro, Jan 17, 2014.

  1. Jack Napier

    Jack Napier (Banned)

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    GT5 had limp suspentions heck GT5 pro had more active suspentions then GT5. Nothing about tuning sus in GT5 was correct. With a limp suspention its all click based tuning and trying to fit theories with result, reminds me of the TV show antient aliens, where facts are distorted to support conclusions. comparisons should be shyed away from. PD fixed much with GT6 but still need to work on tire dynamics quite a bit. We have no telem because it would reveal how little is factorred into the sim correctly. No inside mid outside tire temps, no air pressure adj, no tire/sidewall flex, horendous relationship with tire temp and grip, no brake temp no tread wear patterns.

    With everything revolving around the Tire/Track relationship you would think its a priority.

    I am glad the Nurb runs Kaz did have implimented better wheel angle dynamics even though the poor tyre dynamics still are a bit frustrating to still be around.

    More on topic

    First step is setting up the damps for the spring rate, if you dont do that FIRST your starting from a out of wack point and tracking results correctly is more confusing then conclusive. A SR very high on the slider with low low damp settings is an improper set up and a sighn of click based tuning over actually knowing and understang whats going on.
     
    Last edited: Jan 23, 2014
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  2. Motor City Hami

    Motor City Hami

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    From Caroll Smith's Tune to Win

    The Shock Absorber - "Sometimes I think that I would have enjoyed racing more in the days of the friction shock. Since you couldn't do anything much to them or with them I would have spent a lot less time being confused."

    Another quote, "We determine what we can do with the shocks and when they are right by driving the car and by guessing a lot!"
     
  3. dtimefeel

    dtimefeel

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    That is such an amazing answer worded so succinctly.
    Thank you! I have never learned so much in 30 seconds before :D
     
  4. dtimefeel

    dtimefeel

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    That seems to be consistent with my earlier findings.
    Trying to keep the back high (resist compression, allow extension) increases braking oversteer and reduces power oversteer, for cars that currently braking understeer.
    Do you have any idea why this is the case only for that type of car?

    On the other hand, the tone of this sentence indicates to me that all your cars have needed a (relatively) weaker rear extension damper to counter the power-oversteer.
    That was also the case for me, which is why I fought very hard in this thread.

    If you want to replicate a condition where stronger rear extension damper is needed to counter power-oversteer - use Voodoovaj's Wizard. Using those settings on the Zonda R gave me these conditions.
     
  5. Motor City Hami

    Motor City Hami

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    On other drive trains, I did not need to go to this extreme to get them to turn.
     
  6. dtimefeel

    dtimefeel

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    I didn't mean weaker extension dampers than compression dampers on the rear at all times, but I did mean weaker rear extension dampers than front extension dampers?
     
  7. BlueShift

    BlueShift

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    Yeah, but sticking to it being the Only Truth is the same illusion.

    RH is heigh under the ride, not the actual spring course. On most cars the ride can't touch the floor because of spring course "stops" and/or damper strength, and front spring course can differ from rear spring course, so, in fact it's always easy to put the rh at minimal values, where the actual spring course takes more importance vs RH to calculate the spring balance.

    But to me it's always a good starting point.
     
  8. donpost

    donpost

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    "where does the "always have compression < extension" rule-of-thumb come from?"

    It's because the extension setting is supposed to control the movement of the sprung mass (the car body), and the compression setting is supposed to control the movement of the unsprung mass. Because the unsprung mass is always much smaller than the sprung mass this results in compression < extension.

    Here's a reference that explains:

    http://www.theoryinpracticeengineering.com/drift_mag/basic_damper.pdf

    Of course, there is no way to know if this is already taken into account in the GT tuning screen. i.e. 3 ext/3 comp might be some kind of "default" that this into account.

    Guys - we're only going to get real answers by getting on the track and getting some empirical evidence. Who's up for putting the arguing to one side for a minute and performing some standardised tests and comparing our results?
     
  9. BlueShift

    BlueShift

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    I don't really see a big difference with GT5's dampers. From GT5 to 6, the thing that changed the most were aerodynamics and tire grip imho.

    comp < ext vs ext < comp debate :
    I read yesterday an article from an irl damper ingeneer saying both approaches exists in irl racing. He was a comp > ext guy (like I am) but could understand and describe what happens to ext > comp cars aswell.

    I'm not really familiar with ext > comp cars. I have troubles to "feel" them.

    Main purposes of both approaches are quite opposite and depend a lot of how your driving is.

    I'm happy to be irl conforted that comp > ext is a valid approach. I'm defending this since GT4... :)
    http://www.kaztechnologies.com/file...E_Damper_Guide-_Jim_Kasprzak_Kaz_Tech_Tip.pdf

    Very usefull read. It seems that rating dampers from 1 to 10 is irl related (he uses 0.3 to 0.7 "damping factors" which is damp rendering and, as I guessed rigth, is SR related with a click/10 * SR - I missed the /10 part but used it to fine balance a susp esp low front RH high rear RH like I did on my LFA). The guy gives lots of equations. For most we miss ingame data to solve them, but it's very easy to read and understand.

    You should read this, I think.
     
    Last edited: Jan 23, 2014
  10. BlueShift

    BlueShift

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    Decreasing front ext (up to a point, after this the effect is gone, there's a maximum) decrease front to rear weigth transfert speed but as I learnt yesterday the main damper doing this is still rear comp increase, finetuning front ext will finetune your weigth transfert speed.

    If the weigth move to the rear slower, the rear wheel will have less weigth to support. If your SR is set balanced, then then the rear will more likely grip than with being with too much weigth or not enough.
     
  11. BlueShift

    BlueShift

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    Not really.

    Comp and ext controls both sprung/unsprung moves. They are used with a spring, suspension is your chassis / road interface. As controlling the speed your interface adaptation, they have an action on both elements moving, sprung and unsprung.
     
  12. BlueShift

    BlueShift

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    This is SR related. If I'm finetuning, I try to have front SR*front ext click and rear SR*rear ext click balanced the same way as the weigth distrib, but this can change due to AR bars in "some mysterious way". Same with comp.

    Then I adapt camber to correct this.

    I do this for apex speeds. It seems to me that works very fine in very long curves, where lateral force is your ennemy vs your grip and speed. You can gain 5%-10% of speed there, that a good thing in a 200km/h curve.
     
  13. dtimefeel

    dtimefeel

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    You know me - I'm all for testing.
    What my test results have shown is that

    For Zonda R where dampers aside, it's set up for braking understeer and power oversteer:
    Increasing front extension damper reduces the power oversteer.
    Following the compression<extension rule-of-thumb makes the car yet more stable.
    Reducing front extension damper (as per article) makes the power oversteer worse.

    For Zonda R where dampers aside, it's set up for braking oversteer and power understeer:
    I ran two different setups for BOS/PUS, and the results here are the same for both of these setups:
    Increasing front extension damper makes the power oversteer worse.
    Reducing front extension damper (as per article) reduces the power oversteer.

    I have yet to test these setups with compression<extension rule-of-thumb.

    Do you have suggestions for further testing?
    Perhaps different drivetrains?
     
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  14. Highlandor

    Highlandor

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    Isn't this is supposed to be a tuning forum about GT6, not somewhere where people post real life evidence / articles / experts to back up their theory/ies about what could or should happen in the game....

    If people want to compare real life to GT then why dont they do a thread and analysis that speciifcally details the differences between real life and GT 'setups'.

    Including GT setups that cover the huge amount of diversity in the game, 1200 cars, 3 different tyre types each having 3 different compounds, possibilities of cars with stock power and weight or maxed tuned, 2 main different driving styles - how many situations is that already and we've only just scratched the surface?

    Seperate the people who want to talk real life with those who only deal with what's in the game... Surely it's going to save alot of time, work (and arguements) if both elements are seperated and anlayised individually, then compared.

    Or maybe change the thread title to "real world not GT" suspension theories...or "a comparison of......".
     
  15. donpost

    donpost

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    Maybe I've oversimplified there. I'm trying to back up all of my assertions with expert sources. Here's another:

    http://www.optimumg.com/technical/technical-papers/

    The 6 articles on suspension and dampers are really good reading. Article 4 contains a more detailed explanation:


    I was thinking something along the lines of us all performing the same tests in the same conditions and comparing our experiences. If we all experience the same thing then we can be sure its a real effect and not just a placebo, and we'll have learned something.

    First task should be to decide on a base car/tune to start from. Whatever we choose I believe it should meet the following criteria:

    • MR vehicle - Mid engined cars has a low polar moment of intertia, and therfore any changes to balance will be "exaggerated".
    • Must have a high ride height so that we can use soft springs with lots of movement so the transitions last longer and it's easier to spot any difference.
    • Mustn't be too powerful or difficult to drive - we have to be able to be consistent in our driving to isolate the effects we want to see.
    • No aero downforce affecting grip.
    • I suggest Silverstone as a test track because it has lots of corner types and, being a former airfield, the road surface is very flat and smooth so we can eliminate the "noise" of road surface irregularities from our testing as far as possible.
    I'm not that familiar with the library of cars in GT yet, maybe an MR2? Then we put a tune on it that we are all happy with (leaving damper settings at default), find a section that matches one of Neil Robert's phases and try one of his suggested adjustments. We all goto track with the same settings and adjustments and compare notes.

    Agree/disagree? Thoughts?
     
    Last edited: Jan 23, 2014
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  16. Voodoovaj

    Voodoovaj

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    I never said it was the only truth. Some cars work best undersprung, some cars work best oversprung, some cars work best sprung. What is the default of the car being tuned? If you don't know where you are starting, then are you moving towards a better tune or away from it? I simply believe that spending hours (days?) of trial and error is unnecessary.
     
  17. Highlandor

    Highlandor

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    Ummmm.....I'm confused...which one are you saying??
     
  18. Motor City Hami

    Motor City Hami

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    Not that I want to argue with the all mighty Highlandor, but I don't see anything in the title of this thread or in the OP that indicates this is only about GT6. The title is Suspension Theories R-Us. Kinda captures everything whether people base their findings starting with the real world or starting in game.

    Just my opinion, but I think it helps to understand real world tuning so that you have a comparison to what's happening in the game. I would agree that posting ONLY real world theories without backing it with in-game testing will reduce ones credibility. But, I refuse to discount that the power of real world knowledge will make people a better in game tuner.
     
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  19. Voodoovaj

    Voodoovaj

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    I'm essentially saying both. When you start from the default setting, every car I've tested benefits (in average lap times) from finding the point where it is "sprung". Hence the quote above. They are "better" than default.

    When zeroing in on trying to improve even more, I start experimenting with undersprung and oversprung situations.

    Something like the 70 challenger works "best" when sprung in the rear and oversprung in the front (like the Pozzi Camaro). However, it was still better than default the first go round.

    What setup are you looking for? Better than default? Better still than that? Only the best will do?

    My approach gets you to "Better than default" and "Better still". Beyond that is a realm that I am not skilled enough as a player to benefit from.

    I'll use Praiano's tune for the KTM as an example. I tried it. I was awful with it, but, other (much better) players were in the top 100 on the time trial with it. The tune isn't broken, obviously, I merely do not have the skill to get the car to the pace necessary to make use of it.

    Everyone is looking for a magic bullet, but you can take any number of valid approaches.
     
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  20. Highlandor

    Highlandor

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    I just think it'll help to cut down the work and time to figure everything out, and end up with a better result for both parties..

    I don't know a thing about real world tuning, I look upon the game and setups as a computer programme, within which there is some kind of calculation / equation / algorythm (can't spell it) working with positives and negatives, all I do is try to balance these out, which, hopefully, gives an end result of the car and tyre (wear / heat) being balanced....

    I dont mind if real world tuning is applied with examples for others to re-create and see for themselves, but not alot has examples in GT6 which can be re-created by all or many, which is what prompted me to suggest spliiting things so like minded people can work together, rather than ending up either confused, in dispute, or trying to understand something else (like dampers or camber in real life), in order to understand a post / point someone has made...

    If that makes sense?
     
  21. BlueShift

    BlueShift

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    He says mostly "keep the weigth balance with SR*RH and see if you get better results when you vary from that" (well, maybe not him too but I'm telling that)

    You can then multiply both your SR by 0.8 or by 1.2 depending on you wanting stiff or not.

    My starting point is always front SR* front RH = total weigth, rear SR * rear RH = total weigth * front weigh bias / rear weigth bias. Then I go 0.9/0.9, and so on, sometimes I change the balance just to be sure the balance is still good, etc.
     
    Last edited: Jan 23, 2014
  22. BlueShift

    BlueShift

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    Depends, really.

    What the guy says about comp>ext or ext>comp approaches here (page 12-13-14-15-16) is "the only good approach is the one that makes your car go fast".

    People here, including me, should really be more pragmatic about this.

    My problem is I have a lot of trouble feeling and understanding what is good about ext > comp. I'm not saying they're not good, I just don't know how you make "better" modifications there and how you see bad things you made. With comp > ext, I feel this instantly.

    Are you suggesting a good old tuning challenge there ? :)
    Just kidding. That could be interesting.

    For a really hard car to tune, I tried to max out a red devil, this car is a yellowbird/gt40 kind of "tuning everest" car, I think maxing her out is a lost cause... I'll try anyway.
     
    Last edited: Jan 23, 2014
  23. ace004

    ace004

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    So at what point are we going to start testing and provide data? I see a lot of people tuning via math and then some tuning butt in seat. Both seem to come up with working cars, but I want to know what method provides the fastest lap times. You guys can talk/argue until your blue in the face but half of us will never know which is truly better without lap times to back it up. Also comparing online and offline tunes is pointless as well. We should get a few known fast drivers and a few different cars and compare. Post some tunes, explain your theory, and let some drivers prove your point. If you guys want to make online tunes i will help test.
     
  24. BlueShift

    BlueShift

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    I should put this in my sig :)
     
  25. Highlandor

    Highlandor

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    The hardest part will be agreeing what to test and how...

    The diversity within GT is huge, not just cars / tyres - but as you pointed out you'd like fastest lap time, but others might want an individual part of a setup i.e. dampers.. some might want tyre wear / heat balance (endurance racing)...

    It's going to be tough to find common ground..

    Only thing I can think of is to split the testing up, but have it in a way that anyone or everyone can either participate or replicate...

    One variable that can remain the same could be the cars, take one or 2 from each drivetrain, but even then, there'd be valid reasons that this may not be sufficient, but when other variables like tyres, offline / online etc etc are added, this starts to create quite a substantial 'test'.
     
  26. ace004

    ace004

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    I think we need to do just as you said. Try to agree on a few different cars, pp, drivetrain layouts. If the tuner wants to prove a point then this is the means. It's the only next logical step it seems. And it will be interesting. We might come up with near identical lap times with different tunes. But we will never really know unless we try.
     
  27. Voodoovaj

    Voodoovaj

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    I'll give testing a shot.

    Fairlady Z(Z34)'08 on The Streets of Willow (only ABS - set at 3)

    As is - No modifications

    Best lap 1:22.245

    Fully adjustable suspension on default settings

    Best lap 1:21:884

    Using my FR wizard entering the default ride height (105).

    1:20.589 <- this is using the "medium springs" option which gives a "sprung" condition to the front and rear

    Where do you go from here? I found the front to be a little tight, but this is a point where changes become individual.
     
  28. Highlandor

    Highlandor

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    If this is a test, please could you advise all the missing details so others can recreate this if need be i.e

    Online / offline, pad / wheel (and settings), actual setup (full), car details (new / used - if so milieage), room / track seetings (grip reduction etc etc)

    Otherwise it's going to look more like an advert than a test...
     
  29. Voodoovaj

    Voodoovaj

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    Well, I said the car is AS IS, so the settings will be the same for everyone. There's no need for me to type them all out. As for the settings I used in the wizard, they were raw settings that it spit out, so again, it will be the same for everyone. I never drove the car before this moment.

    I used a pad and I did this offline.

    Track settings are also default
     
  30. Jack Napier

    Jack Napier (Banned)

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    Yellowbird Tunes and drives like a Porche in GT6 (finally) still plagued by horrible tire/temp/grip dynamics in GT making her a bit tough at times, but in tge end just another car in GT. Gotta have some skillz to handle her maxed out as does a real 80's Porche 911. Stock power is still more then a normal 911 but a much more friendly beast then maxed out.

    I run her lap after lap inside tenth, 1:25 easy at Brands on RH maxed out just over 600pp.

    Video vefore tune coming as I slaughterred the Acentador but i think a video showing what it can do abd how it goes where you pointed is needed.....