GT4 and Brakes

Discussion in 'GT4 Tuning' started by Scaff, Mar 18, 2005.

  1. Mt. Lynx

    Mt. Lynx Premium

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    Yes,yes, I always adjust all settings possible too, it was just a thought, and not really important, just a silly point. And best default? Does that exist? :)
     
  2. Polyphony001

    Polyphony001

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    Not to my knowledge...
     
  3. Cosmic

    Cosmic (Banned)

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    You guys should give the Mini Cooper S a try.
    Tune it to max (R5 tires!) and set the brake ballance controller to 4-4.
    I think I should set it lower since it stops in a way too short time :dopey:
     
  4. Polyphony001

    Polyphony001

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    The Fiat Coupe Turbo has ridiculously good brakes stock for some reason...
     
  5. sucahyo

    sucahyo

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    Different BBC on TCS=10 Opera 350Z, feel check

    I want to know if this is only wrong feel or not.
    using my setting, I feel that by using no TCS the car braking on 1/1 BBC feel terrible, the wheel is locking (I am using faked controller, so braking is always full braking). IIRC, braking will make the car the loose traction, mainly from rear, as the car do not plow. It result in sliding sometimes.

    The car behave very differently when using TCS. When using 10 TCS the car braking feel very understeer on 1/1 BBC. So I end up increasing the rear to make the car less understeer. By setting the BBC to 1/10 I make the car has slight understeer behaviour when braking. Using 1/14 BBC make the car slightly oversteer.

    Base from this I made a conclution that using TCS will change the braking balance of the car.

    I need sugestion for what BBC value that is ok for no TCS Opera 350Z too. As I failed to understand how GT4 braking works. I made the wheel lock at 1/1 BBC and stock brake. Do increasing the front BBC will reduce locking?
     
  6. Scaff

    Scaff Staff Emeritus

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    OK a few things that need to be covered here

    First is regarding the TCS system and how it effects braking. I can state quite clearly that it has no effect on the overall stopping distance of a car (this was tested here), however it does have an effect on how the car responds to direction changes under braking, however qualifying the nature of this is far more difficult.

    What it certainly does not do is change the brake bias, as this would result in a change in stopping distances. Its more likely that its controlling the loss of traction as the car turns.

    You have also asked if setting the BBC values higher reduces 'lock-up', well first off true lock-up does not occur in GT4, as the ABS system will control it. What happens is that as we increase brake force (or screw up the brake bias) the lock-up and therefore ABS intervention occur earlier. This does cause an increase in stopping distances (again the linked test above clearly shows this) and can be clearly heard and felt when it does occur.

    The very active ABS in GT4 is also one of the reasons why setting a stupidly high rear brake bias does not cause massive car instability, which would be the result in the real world.

    I personally do not use Brake Bias (BBC) as a tool for resolving under or oversteer issues, rather I use it to maximise the use of the availiable grip the tyres offer to stop the car as quickly as possiable, in the shortest distance possiable. Remember in GT4 we have a huge number of options in suspension tuning to control under/over steer, but only one to control the brake balance and optimise the stopping distance.

    In terms of how to set-up the BBC, this is covered here, and in much more detail in the first of my tuning guides. Its not possiable to state a BBC value that will work in all situations with the Opera 350z, as it depends on the exact suspension set-up, corner you want to optimise the braking for, the tyres you are running, etc. However reading the above link (or the first guide) should give you a much better idea.


    As one of the judges in the tuning competition who tested all the cars involved (including this set-up) I have to say that the main factor in the handling issues with your set-up are not a result of the Brake Bias settings. Rather they are a product of the extreme nature of your suspension and LSD settings, trying to resolve this through the BBC did not work, in fact it simply compounded the problem as the BBC settings have most likely increased braking distances.

    I would suggest going back and trying some of the other set-ups that people submited for the competition and looking at the comments the judges made about them. In regard to your own set-ups I would suggest going back to my tuning guides and look at the example set-up and try following along with it.

    Regards

    Scaff
     
  7. sucahyo

    sucahyo

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    Ok I will go back to experimenting again.
    From the competition, which setting has the best braking?

    From you view what is the best replacement for BBC for reducing braking understeer, assuming other behaviour is ok ?
     
  8. Scaff

    Scaff Staff Emeritus

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    As far as the set-ups from the tuning comp go, my personal favorite was gregc's, so I would suggest giving that one a go.

    As far as settings to reduce understeer when braking, we can do a number of things depending on the car and its set-up. Factors that will play a part here are spring rates, dampers and anti-roll bars, as these are major factors in determining how the load that is transfered to the front is distributed between the two front tyres.

    You have to remember that the main cause of understeer when braking is overusing the grip you have avaliable from the tyres, and in a cornering and braking situation you are asking the tyres to do two things. So the need to ensure that each tyre does its share of the work (which in cornering will not always be equal - the outer front tyre will normally have more asked of it).

    From your set-up a number of issues are quite clear, firstly the LSD settings, at the lowest level like this you may as well of not bothered fitting one, its effectively running totally open, giving no benefit at all.

    Moving onto the suspension set-up, you have a big difference between the front and rear spring rates, the rear being twice as stiff as the front, not realy a good move in a car that has a static weight distribution of F52 : R48 (for a standard 350z), however thats nothing to the damage that the damper settings have caused. Now I know that we fundamentally disagree on this next point, but maybe by trying some of the other set-ups you will see what I have been saying for a long time.

    Take gregc's set-up, he is running much stiffer springs at the front end than you are, as well as stiffer anti-roll bars, but his car did not feel as stiff as yours. The single reason why is that the rock solid damper settings you are using as overwhelming the spring rates. Its one of the principal factors that is totally killing your tune.

    If I can be totally blunt and candid, your set-up looks rushed and badly thought out, it almost seems as if you simply threw extreme settings in place and when they didn't work, threw some more extreme settings at it again and when that did not work you slapped TCS up to 10 and hoped. Quite simply this is not going to work in GT4.

    As I said before, go back to the first of my tuning guides, buy an M3 CSL, fit the FC suspension. Then go to the Grand Valley Speedway and follow the example of a tune. See how making small changes can have a major effect, big changes just cause big problems, particulalry if they are all done together.

    In regard to not having a DS2 and I believe no analog brake (and I assume also no analogue throttle) this is going to give you problems and you may want to try using the sticks (I use the right stick for brake/throttle when I use a DS2) or 'pumping' the brake button rather than just jamming it down.

    Regards

    Scaff
     
  9. ~Sp33~

    ~Sp33~

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    I really hope that in gt5 you can properly lock up the tyres. I remember i could in gt3 even if only briefly. The brakes in gt4 are rediculous as far as performing emergency stops go. really takes alot of fun out of driving in the wet too.
     
  10. Scaff

    Scaff Staff Emeritus

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    Quite agree, as while the stopping distances in GT4 (with N2 and/or N3 tyres) are quite close to real world figure (which GT3 figures are not), little skill in required in extracting the most from the tyres under braking.

    This weeks Autocar has a perfect example, as part of a group test then were testing a TVR Tuscan 2, it shares the quite typical TVR love of trying to swap ends under heavy (straight line) braking. Yet try hard braking in a TVR in GT4 and you have a perfectly stable car that stops with little or no drama. Its also more than slightly bizzare that all cars in GT4 have ABS (with no way of turning it off), when every TVR made is most certainly not fited with ABS.

    Its oneof the areas that Forza is ahead of GT in, the ability to turn off the ABS, it makes quite a difference as well. Oh well fingers crossed for GT5.
     
  11. sucahyo

    sucahyo

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    ok.

    ok.

    My current tuning is increasing LSD when needed, and I highly suspect this car has some LSD value stock, maybe 10/40/20 or something, too bad I can't confirm it (I can't find credit in emulator :ouch:). So I choose fitting custom LSD and minimize it.

    This is what surprise me. I thought this car has heavier front too. At GT2, with the same way of tuning, I usually need to make the front spring rate higher if the car has heavier front, about 20/12 or 20/8 if worse, like some FF and FR. I make the rear spring rate higher on MR and RR, about 16/20 or 12/20. Somehow, when I use spring rate this high, my laptime is better. NTSC version only though, this value is too stiff for GT2 PAL version.

    I take the car to deep forest first, since this is the track that I am more familiar with. With my initial setting, both spring rate at 7.0 and LSD at 0, I feel the car a bit oversteer. Ignoring that, suspecting the car as having heavier front, I raised the front spring, make it 17.0/7.0. Surprisingly this car become more oversteer, make it very hard for me to drive it properly. So I make it 7/0.17.0, with this stiffer rear I feel the car easier to handle for me, I can use it to do clean lap on deep forest. So I end up using this as my final spring rate setting. Since this give me safer ride, I don't test other spring rate combination, my mistakes.

    With stiffer rear spring rate needed to make it normal (for me), I conclude that this car has havier rear.

    Seeing my setting, I began to suspect that higher spring rate increase grip more in GT4 than GT2 as all judge rate my setting as very bad understeer. Funny that using spring rate so high in the rear with high damper do not make the rear skates around/loose traction at corner. Is it really like this in real life? or monaco just too smooth? This is different from what I feel from Viper Racing (old PC game where you can see the suspension at work):
    [​IMG][​IMG][​IMG]

    The reason for high damper is I currently experimenting wether the handling has to be smooth (low damper) or harsh (high damper) to make the car stick to the road more. In GT2 I found harsh is better. As I don't have problem taking clean lap (maybe slow) in monaco, I thought harsh is ok.

    I use my current GT2 formula, wether this is good or not, I will know when GT2 competition result came out. In the mean time, I find that using this can make me win GT2 world cup in Renault Espace (underdog car) easily in normal tire where Parneli Bone have tough time with it in super soft tire. As I believe my skill is bellow him, setting is my only explanation, and this setting do not use my usual trick, it is almost the same as my Opera 350Z setting.

    I use TCS to cure problem with loose traction on acceleration. Normally for this kind of problem I will use stock flywheel and highest final drive. Since I never use TCS in GT4 before, I want to giving it a try (never thought in end up bad in judging) as using it in GT2 definitely increase the car acceleration (1000mph, laptime and race test) and reducing whell spin at the same time. To my surprise, fitting a TCS make the car understeer very badly at full braking, when before fitting it the car only slide around, after fitting it I hit the wall often because the car refuse to turn when braking. So I increase the rear BBC to 10.

    Seeing the TCS is my biggest minus point in competition, I conclude that TCS in GT4 is damaging. It reduce wheel spin, but it reduce acceleration too (conclution from competition judging).

    BTW, do you test my car with TCS:10 or not?

    Ok.

    Ok. I'll try that.


    Thanks for giving my setting judging in detail :).
     
  12. Scaff

    Scaff Staff Emeritus

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    I don't disagree that the LSD settings on the car could benifit form a tweak, but by fitting an FC LSD and setting everything to minimum you caused yourself no end of problems. These settings basically run the diff wide open, as such once a wheel starts spinning the diff is just sending all the power straight to it. One of the reasons why you have to set TCS so high to lay any traction down is because of the LSD settings.


    A 52%/48% front/rear static weight split may make the car slightly front biased, but we are only taking about a very small front bias, yet the settings you are discussing above give a massive bias to the front.

    You need to almost totally forget about how you tune in GT2, you can get away with very extreme settings in GT2 that will have very little real impact. Doing the same in GT4 will almost certainly have a major negative impact on the car.

    Th eother thing to remember is that static weight distribution is just that, its static, as soon as the car is in motion its constantly changing and moving around. You need to drive the car and see how it reacts to the different parts of a circuit and the different stages of a corner. Identify wht a works and what doesn't work and tune to remove the problems without harming the good stuff.

    It takes time and a lot of testing, but most of all you need to make small changes to one part of the suspension at a time. Throwing half a dozen changes in at once will just totally confus the issue.


    The problem with that approach is that Deep Forest is nothing like Monaco and a set-up for one is never going to be good at the other.

    The comp asked for a car set-up for Monaco, so you need to tune at Monaco.

    Also as I mentioned above you are jumping from one extreme to the other with your settings, this is never going to work as an approach. In my tuning guides I strongly recomend setting the suspension up to first deal with the nature of the track, which for Monaco is actually quite smooth (Deep Forest on teh otehr hand is a very bumpy place) and once thats done, then moving on to tuning for the car balance.

    In my opinion its the only way of tuning that will correctly set-up a car for a track every time, you can't do one while you are doing the other.


    But thats the problem, at rest the car does not have a heavier rear. It will however have a heavier rear under hard acceleration as the load transfers to the rear and a heavier front end under braking. Not to mention a shift left to right (or right to left) when cornering or changing dirrection.

    Its one of my pet hates when people just simply state that a car understeers; as every car is capable of understeering, as a statement on its own it is of no use at all. To know how to tune a car you need to know its balance and the conditions that the balance occurs in. I mean almost every car will understeer under braking when entering a corner, thats the laws of physics, you are generally overusing the front tyres. In most cases the best you can (and would want for) is to minimise teh understeer as much as you can.

    To be honest wit hyour set-up the problems are multiple, the only reason the general corner exit balance is understeer is not because the rear is not losing traction, quite the opposite the rear is most certainly lossing traction. Its just that the front end is lossing more traction (stupidly stiff dampers that restrict the springs and a reduced load from acceleration) than the rears.

    The causes of under and oversteer are much more that just which end has lost traction, its determined by which tyres have the greater slip anle/percentage combination.

    As with most things in tuning you get advantages from both, generally you will need lower damper values to obtain better traction if the track is bumpy (which Monaco is not massively), but neither is the track perfectly smooth and the suspension still needs some compliance. As such while the dampers do not need to be set very low, jumping straight to maximum values is going to cause just as many, if not more problems.

    This is a track that will benefit from a generaly stiffer set-up, but that does not automatically mean that you should set them rock hard.

    Additionally as dampers can have such a major effect on the spring rates is set too hard (or too soft) great care needs to be taken with very extreme values, particularly if the car is very light or very heavy.


    To be 100% honest, quick tuning methods that work in GT2 will not work in GT4, forget them and adopt a more structured and subtle tuning method.

    TCS is a driving aid and it will react to reduce (or remove) wheel spin or tarction loss. To be quite honest if a set-up needs TCS 10 to be driven then the set-up has major problems in its own right. My TVR Speed 12 set-up uses no TCS at all, yet is actually quite driveable.

    If you have to use TCS to remove a problem or make a car driveable, then to honest you will stand very little chance of winning tuning competitions, particularly if you need to set it as high as 10. Set it to zero and tune without it, that way if the set-up works, it works because its a good set-up. Anyone that then needs to add TCS is doing so because of the abilities they (don't) have as a driver.


    Both with and without. With TCS it was poor handling and slow, without TCS is was undriveable. Sorry, but I can only be honest.

    Its not a problem at all, that you for accepting and taking on board my thoughts. I would always be happy to comment on yours or anyones set-ups and offer my advice or thoughts (just not entries for the tuning comp when I am judging - at least untill after the results are printed)

    Regards

    Scaff
     
  13. FormulaGT

    FormulaGT

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    I just thought I'd chip in a thought here. TCS is often a NESCESSITY for players (pilots) using a DS2 not a Wheel. Even with pressure sensitivity, it is not sensitive enough, at least for me, to allow for TCS to be disengaged. Saying that if one uses it they are a 'less abled/skilled' driver (your comment was not as strong as this, but was the closest I could think of), I can only assume that you drive using a Wheel not a DS2. As soon as you step up to higher powered cars, you lose much of your control over wheel spin and TCS becomes mandatory if you plan on winning a race. Take, for example, the Formula Gran Turismo '04, it is exceedingly difficult to control wheel spin sans TCS on a DS2. ASM is another story (and one of relative ease), but I just thought I'd add something from the DS2 front and hopefully people will see that there are added challenges on both systems. As a side note, I usually tune & drive with TCS at 5.

    *Nothing personal here, so please take this as an opinion only :tup:

    FormulaGT
     
  14. Scaff

    Scaff Staff Emeritus

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    I would agree that it is personal, and for the record I use both a DS2 and a wheel (depends if I can be bothered to set the wheel up).

    While fine throttle control is easier on a DFP, its by no means impossiable on a DS2. I don't change the TCS setting between the two control methods, no matter what the car or the race.

    I do find it easier on the DS2 if you use the R. stick rather than the buttons (but I know of some who do use the buttons just fine).

    However the main point I am making here is that a TCS setting of 10 is simple being used to mask a flawed set-up, 10 is (in my opinion) never needed. Even a setting as high as 5 is a major piece of assistance to the driver and even with the DS2 a degree of self-control (not just mashing the throttle) and practice will always be better.

    Regards

    Scaff
     
  15. FormulaGT

    FormulaGT

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    As I said, nothing personal meant. I use the buttons (Sorry, I forgot about the R Stick!:dunce:), always have. I usually play around with the aids after I've made the tune, not to mask flaws as such, just to suit the car's power and make easier to concentrate on the track rather than the exact amout of throttle being applied. I usually don't drive with ASM, but on cars such as the Formula GT, it (for me at least) produces faster laps with ASM & TCS on. Also, since you cannot tune the stabilisers, the suspension aspects seem to go against each other & TCS is useful for asisting against this. You can probably give a much more accurate account of what happens here, but this is just what it feels like.


    FormulaGT
     
  16. sucahyo

    sucahyo

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    Scaff, thanks :)

    Agree about LSD.

    About weight dist, I don't (can't?) feel any negative feel by using massive bias. But I think I should put more attention to it next time.

    About stiffness, how do I measure that my car is too stiff in GT4? In gT2 it is always obvious when your car get thrown to understeer or oversteer in bumpy corner.

    Ok, monaco and deep forest is different.

    About heavier rear conclusion, I came to it because it is become less oversteer both at acceleration and braking when I increase the rear spring rate, something that I usually do to a car with heavier rear in GT2. This is before I put in TCS, so at this stage I don't feel the braking understeer yet.

    About front end is lossing more traction, I don't get it, are you saying that the rear does skatting around, but the front does it more on less spring rate?

    About damper too high, I want to start tuning with the least restriction for the suspension, let it jiggle or bounce more at bump, as I believe less restriction to the suspension has better traction too, this mean using lowest stabilizer and highest damper (I still belive that high damper value give the least restriction to suspension movement). As long as the car do not have problem loosing traction from too much jiggle or too unconnected steering I usually don't alter it.

    About GT2 tuning do not work in GT4, I still looking for the relation between the two. For the mean time I feel the GT4 closer to NTSC version of GT2 than the PAL GT2.

    About TCS in competition, thanks, I will not use TCS in my next GT4 setting.

    I am tuning the Viper RT/10 with no TCS with more attention (time) to tuning the behaviour when braking, accelerating and cruising, really looks forward for the result :).

    I think we should alter our tuning and do the tuning procedure again after fitting or unfitting TCS to make our car perform well. Just like the unexplainable understeer on my Opera 350Z AFTER using TCS 10, when it doesn't as understeer before. It require me to change the BBC (Now I think I should change the other setting too).
     
  17. Scaff

    Scaff Staff Emeritus

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    I would certainly suggest more attention next time as the massive bias feels awful on this car, but I suspect that the controller you are using is a part of the problem.


    As I have always maintained feel is one of the most obvious ways, I personally find it very easy to tell if a car is set up too stiff. However you also have to take into account that a set-up that is too stiff for one driver may be fine for another.


    But you haven't just increased the rear spring rate, you have also lowered the front spring rate, reduced the Anti-roll bars and maxed the dampers. As these will also have a major effect on the cars balance you can't say this means the car has a heavier rear.

    Point of fact - the 350z has a near 50/50 static weight distribution, conclusions from how you feel the car handles after you have altered the set-up are not gvoing to change that fact. Also, as I have pointed out many, many times, extreme settings produce extreme results.

    The thinking that simply going lower and lower with a setting (or the reverse) is going to give more and more grip at that end is unrealistic, simplistic and flawed. Its a concept that worked fine in GT2, but has no place in GT4. Beyond a certain point overly soft (or hard) suspension set-ups start to cause big (and unpredicatable) problems. Its why jumping to extreme values will not work.


    See the above, you are working on an oversimplistic and flawed piece of logic. You can't just jump to very low front spring rates and very hard spring rates and say you will get a set result. It does not work like that in the real world and it doesn't work like that in GT4.

    However as I have said before the max'd damper settings are also a major part of the problem here.


    Yes but the problem here is that your set-up (and it was not just me in this) does have massive traction problems, it does have an unconnected feel to it and its does feel far too stiff. The high TCS setting may have masked some of this, but with the TCS turned off it displays almost all of the characteristics of a car that is so massively over-damped as to be almost undriveable.

    It may sound a little arrogant on my part, but do you know how many people have used my guidelines to learn (and improve) there tuning abilities? The fact that I use a totally different approach in this area, and that it works for everyone that trys it should indicate something to you.

    Quite simply you are again providing your own evidence that lower damper values = softer. As a side note it is also worth pointing out that Tourist Trophy (which shares a lot in common with GT4 - and I suspect a lot of code given the short development time TT had) quite clearly states that lower da,per values are softer and higher damper values are stiffer.


    For every one of the reasons I have given above I am quite adamant that teh physics engines are so different between the two that simply translating GT2 tune to GT4 will not work. I mean even good set-ups I had from GT3 needed to be adapted to work well in GT4.

    Regards

    Scaff
     
  18. sucahyo

    sucahyo

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    About weight dist, I am thinking about this, a car with balance suspension bias:
    • will not nod, the car hopping on bump or road irregularity, but either the front or rear will not nod. Nodding is a sign of different natural cycle per minutes between front and rear. A balance car should have equal front and rear natural cycle per minutes. So when it meet bump the front and rear will have the same bouncing frequency and will nod result in nodding.

      I think of this because my Opera 350Z has rear nodding problem, when the judge state my car has big understeer problem, I relate this to this rear jiggling, I figure that if I reduce the rear spring enough to eliminate the nodding, the understeer will be reduced too.
    • when the car jump or fly, the tire will land at the same relative timing. when the front land at longer timing it has spring set too soft or height set too high, or the opposite.
    • when driving it slowly on bump, the amount of body jumping of the front and rear should be the same.
    The last two is what I experimenting in GT2, this is also why I test the Opera 350Z to deep forest first, too see how I can equalize front and rear jump, the hint is the rear jump more than the front at equal setting. It looks jump equally at front bias spring rate. I ignore this since this make the car so oversteer that I can't handle. But the judging show that I should put attention to this. The tuning competition really help me understand tuning better :).

    About unrealistic tuning, if the car will oversteer with massively front bias spring rate, I guess I just have to use it no matter how unrealistic it is.

    About extreme value, I am a bit surprise that using extreme value in GT4 do not make the car undrivable (I am not using this kind of tuning in previous catterham). In deep forest or monaco the Opera 350Z hold the road well, even on bumpy corner, I can drive it with ease. As using the value so high or low do not make the car undrivable for me, I still consider it normal. Still need to learn a lot of GT4 physics though.

    About damper, you say max, I am saying it's low :) (Don't know about TT though). It doesn't give me problem driving it YET. As I improve my GT4 driving skill I may consider again on how much value that I should use for damper to be fast. With my current driving skill, I think I will keep using it.

    About guide, your guide is excellent for improving car handling, it's just that I want to find the shortcut for tuning, which setting will give faster time no matter how irrational it is. So currently I don't tune to make it handle better, I tune to make it faster. That is faster because the game special feature, not because it handle batter. There is many thing I can learn from your guide. But I only have little knowledge for GT4 special feature, most of them from 300mph. So I will keep experimenting until I find what special tuning feature exist in GT4. My goal it to make tuning formula that can make the car drivable and fast. I just wish I have good driving skill and appropriate controller to make it happen.

    My current guess for GT4 special tuning feature:
    - ride height, higher front have better high speed acceleration.
    - final drive, behave like flywheel
    - spring rate, same behaviour as GT2, the relation to traction still need to be tested

    about GT2 and GT4 is different, I only apply my GT2 knowledge little by little, for thing that I certain should be the same.

    as my Opera 350Z do not tuned for zero TCS, I hope you can explain what my Viper RT/10 undrivability behaviour is on your next judgement. I put more effort when tuning this Viper, I try to make it more drivable on zero TCS. Really look forward for the result :).
     
  19. Scaff

    Scaff Staff Emeritus

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    I'm going to reply to this one and then leave this until the Viper tuning comp is finished, only on the grounds that this is now starting to get way off topic or this thread.


    Even if you had a car with exactly 50/50 front to rear and left to right static weight distribution and equal suspension settings all around (and assuming a 1:1 wheel to spring rate at each corner as well), it would still only ever be balanced when stoped on a totaly level surface.

    The second a car starts to move its balance shifts, the COG moves around, the more lateral and/or longitundial force is placed on it, the more the load transfers.

    Trying to use this visual nodding as the main judge of spring rate suitability is not accurate, for the reasons I gave above, but also for the previously discussed problems of potentialy different spring to wheel rates, damper influence and anti-roll bars.



    Again this has been discussed many times before, the only thing seeing how a car reacts over a jump is good for, is tuning a car to react to a jump well. For handling, cornering or speed it is no damn good at all.



    See above, how a car reacts on a jump is not a good indicator of how it will handle or how to tune it for handling or speed. You do not see F1 teams taking the cars over jumps to set them up.



    I did not say that extreme values don't make cars undriveable in GT4, quite the opposite, extreme values do make cars undriveable in GT4. GT2 lets you get away with the extreme values.

    I would agree that extreme settings do not have as extreme as effect as in the real world, but then we can't use spring rates or damper settings that have real world extremes in GT4 (spring rates maximums are a good example - real world spring can get much firmer than in GT4)

    I have to say that if you found the Opera 350z an easy car to drive with TCS turned off then either you drive very slowly or you have yet to experience a well set up car.

    Try a back to back test with your set up (without TCS) and gregc's set up (with out TCS) and PM me with your finding.


    TT is not up for discussion or debate, handling clearly shows which is soft and which is firm, and the text on screen clearly says so. Do not even start that one.

    As far as GT4 goes, you still maintain your view, and thats fine. The only problem comes with your set-ups, if you continue to max them I doubt you are going to see much improvement.

    Have you ever considered that one of the problems with your driving could be the way in which you set cars up? Maybe if you stoped in your blind belief and tryed a few other things them might improve.

    I wait with interest your PM on the set-ups test.



    I do not personally believe that a 'short-cut' to tuning exists, no one set-up method will give 'best' handling and 'best' speed for any car on any track. The sheer number of hours I have spent tuning and testing in GT4, I can say that your quest is a pointless one. You would be better served spending your time actually learning how a car works under motion and how it applies to gradual tuning methods.

    The 'game special feature' you describe was a quirk of GT2, it was never found to exist in GT3 and has not been found (and is even more unlikely) in GT4.



    So do I


    Regards

    Scaff
     
  20. Uncle Harry

    Uncle Harry

    Messages:
    1,414
    Sorry to take this off topic even further.
    I 100% agree with Scaffs above statements.
    Probably the fastest "quick set up cheat" is to use the default set up PD provides for the cars with the ASM and TCS at default also.
    While doing some testing I found they actually work quite well for the Nissan R89C.
    The hard dampers and springs work quite well with the ASM masking any oversteer and understeer problems. I usually do not drive a car such as this with default settings but it is a interesting test to see what PD gives us.

    However when you remove the aids all the faults Scaff has outlined become apparent on this car.

    Maxing out the settings is not the correct solution.
    And one more thing, setting one fast lap that can not be repeated over and over is not a good set up.
     
  21. sucahyo

    sucahyo

    Messages:
    2,171
    about visual, I use it because I don't know what other method to do it.

    How do you know that you are using the right spring rate and ride height to match the car static weight distribution?

    Derivating car natural frequency formula do not work because on zero spring rate GT4 roadster will still bounce. Since the zero in suspension setting is not really zero springiness, using formula is not applicable. To keep in topic, I think this also true for using formula to get initial BBC setting. Since zero BBC do not mean no brake power too.
    This is what I have in mind:

    spring rate accepted in GT4 engine = x + spring rate in GT4 setting screen * y
    brake force accepted in GT4 engine = a + brake force in GT4 setting screen * b

    Since we can only guess what the a,b,x and y is, using formula is not applicable, even if only as initial setting. but, this is only my opinion.
    my proof:
    BBC : 4 is not equal to twice brake force of BBC : 2

    If the car hav 54:46 static weight dist, we can only assume that asigning 5:3 is correct. But we can't blame it too when someone use 10:1, if they assume the b value is very small and a is big. And even using this we use an assumption that front and rear BBC has the same multiplier.

    The best solution is to use data logger to find the correct combination of BBC that give good braking and good handling.


    about F1, they have the tool and gadget to do that, why bother visual.

    about extreme setting, I suspect GT4 spring behaviour is unrealistic. Since I don't know how it supposed to be in real life. But knowing that extreme front bias spring in Viper racing (created by nascar heat creator) give understeer, I am guessing that doing it in RBR will result in understeer too. If giving too much front will make the car understeer in those game, using too much overall spring will lower the traction.

    In GT4 (or 1,2 or 3) the spring rate tuning is different, since extremely too much front will make the car oversteer, using too much overall spring will NOT lower the traction, it will increase the tire traction.

    Conclusion from above, in GT4 we should use spring rate as stiff as possible.

    I don't know any other explanation why extremely rear bias spring will make the car understeer in GT4. So far on GT4, I only try this on Opera 350Z and Viper RT/10.


    about driving without TCS, I said that I don't tune it for that, of course it will be undrivable for me too. And I don't think it's fair to judge gregc setting without TCS, because he use TCS when tuning. If I intend to not using TCS, my setting will NOT be like that.

    about undrivable in GT4, with faked controller, I find extreme spring still drivable in GT4. I never hit dirt because uncontrollable boucing or turning, it is either too fast or brake too late. I don't find using extreme setting make driving harder, I don't find any difference between normal setup and extreme setup. I find extreme spring bias setup to be easier to drive than normal equal spring setup (my previous tuning).


    about special feature, that feature is for GT4, try to race in 300mph sometime, you will never make 1st position with equal ride height. the difference is between 260 mph and 240mph at test track corner. IIRC, it is found in GT3 too. It is definitely not GT2 special feature, as ride height is reverse of that in GT2. It is GT4 quirk.

    about default setup as quick setup cheat, this not using any special feature, so I think it is slower than if we use the special feature. It will give good handling, but I am not sure if it give the best speed.

    a special feature should make our car faster on repeated lap.

    max/min-ing thing is normal when gaming :). There should be spesific rule exist in each game. We just have to find what the rule is ..............
    In 300mph thread I learn that to be number one I have to know what rule exist in GT4 high speed :). Look some example of 300mph car, it is unrealistic, but it is usable, I consider it normal. I am thinking that track tuning is the same way.
     
  22. Scaff

    Scaff Staff Emeritus

    Messages:
    24,462
    Location:
    United Kingdom
    Your famous short term memory issues strike again. How many times does this need to be explained? Tuning is a combination of hard data (from the data logger & consistent lap times), visual information (from replays) and feel (from the drive).



    First why are you talking about ride height? You set ride height based on the spring and damper rates in conjunction with the track you are running at.

    As far as setting the right spring rate, again this was covered in my first guide (which you claim to have read), but as a basic guide I would use the static distribution to establish the front / rear ratio and then drive the car, working on the points covered in the post above to tweak the car. I do not use short cuts or formula to set-up a car, I do not personally believe that this approach works at all.

    I would also set the dampers to a level of around 5 before doing this to ensure that they are not restricting the springs during testing, again this is covered in the first guide.



    That’s funny because I told you weeks ago that this would not work, at the time you said I was wrong.

    As far as setting brake bias up goes, once again this is covered in the first guide (or a direct link from the first post in this very thread), it’s a very, very detailed method of setting brake bias. Go and read it.

    It is also becoming quite clear that while you claim to have (and I have suggested many times that you do) read my set-up and tuning guides, this simply can not be true as you are constantly asking questions about subjects I have written about in great detail.



    That’s not proof, that a statement, two very different things



    The best solution is to actually go and read what I have written on the subject, as again you are stating opinion as fact.



    Same reason they still ask the driver, ‘tool and gadget’ only get you part of the way to the correct set-up. Human beings are all very different, a set-up can only be finalised with driver input and with the assistance of visual information.



    Extreme front bias what way?

    Again this is talked about in the first guide (please go and damn read it) in which I quite clearly state that extreme settings can and do produce unexpected results. If I was at home I could quote Skip Barber on just this subject, excessive settings in either direction will not always produce the expected result. In the real world and I’m glad to see GT4.

    However we still have the issue with your set-up that the spring rates you are using as being restricted by the dampers, you are looking for a reason as to why the spring rates are not behaving as you expect. I’ve already given you two, the use of extreme settings and the restrictive damper settings, however in characteristic style you have chosen to ignore them in favour of your own ‘pop’ theories.




    I’m sorry but that is (as far as GT3 & GT4 go) complete rubbish, in the course of writing the guides I have spent hundreds of hours testing settings in GT3 and GT4, I wonder how long have you spent to make such a certain and bold claim?



    Conclude what you like, it depends on the car, track and driver. Formula set-ups will not work for every car, on every track or for every driver. To try and claim otherwise is simply ridiculous.



    I’ve given you numerous reasons why, you just ignore them in favour of your own (generally ill conceived) theories.



    I’m sorry but in my opinion (and I was not alone) your set-up was poor and slow with or without TCS, TCS simply masked the problems with your set-up.

    In regard to gregc, it was perfectly fair to judge his set-up with and with-out TCS, as long as I am clear when discussing this.

    If I recall correctly I actually said that I found his set-up to be better without TCS, but did also say this was obviously a personal thing.



    Un-driveable can (and does) cover many things, not just uncontrollable bouncing, Your set-up, both with and without TCS, resulted in a much lower cornering limit through extreme suspension settings, it increased the cars stopping distance through grossly unbalanced brake bias and a combination of the suspension and LSD settings massively reduced the cars ability to lay down traction.

    As I mentioned before if you found this car to be easy to drive, then I seriously doubt that you were pushing its limits, as those who did during the tuning comp found it a very different car.



    I have previously and in detail discussed the issue that exist with the application of downforce in GT4, this is the crux of the issue with 300mph+ speeds.

    In regard to trying a 300mph+ run, you may want to search that thread a bit more carefully, as I completed mine (TVR Speed 12) before you did.



    A car that is set-up to handle well on the limit will be a quick car. I again ask how long you have spent tuning on GT4, as no ‘special feature’ has been found by anyone else. You are once again stating its existence as fact, when in fact it is just conjecture on your part.



    IT DOES NOT EXIST – you have shown no evidence for a ‘special feature’ that will make every car handle well on every circuit.



    It may be in your opinion, its certainly not in mine.

    Why should the game have specific rule that allows this to happen?

    The 300mph issue I have already covered, but it does not mean that it must apply to track tuning. That is quite simply a flawed piece of thinking; you are making a huge assumption based on no direct evidence and wilfully ignoring the experience of others. Some things never change.

    Regards

    Scaff
     
  23. Mt. Lynx

    Mt. Lynx Premium

    Messages:
    2,975
    Location:
    Sweden
    @ Suchayo; I think you are delving too deep in issues that you don´t really have to care about. This is because you are too addicted to visual tuning.

    Just take whatever car to whatever track and drive it as it is, then take away ASM and TCS and drive again. Feel the difference! Then start to slowly try and fix whatever problems you are experiencing (understeer, oversteer, jumpy, hard suspension and so on), by changing setups little by little. When you feel (and obviously see how laptimes improve) that the car behaves properly, you have a proper setup! A good car to try this with would be the BMW 320i Touringcar around Deep Forest.

    Do this, and you have no need to know the cars weight distribution, or how much it nods front and rear. If it feels OK, it probably is OK, no matter how strange the setup may look to you.

    And as for 300mph tuning - it has very little, if anything, to do with tracktuning! The 300mph tuning is simply taking advantage over the somewhat flawed physics of GT4 (read: aerodynamics, centrifugal forces).
     
  24. sucahyo

    sucahyo

    Messages:
    2,171
    About weight dist tuning, that method only work for you who have good equipment and decent driving skill. For me who doesn't have that, fast tuning for me is safe tuning, tuning that reduce mistakes. No way I will know that my tuning match static weight dist without visual.

    About formula, if you based your tuning by static weight dist, you are using formula.

    About initial damper value, it's based from what we believe. I believe 10 is the least restricted.

    About spring rate formula, I forget what I said. I change my way of tuning recently.

    About BBC, I am saying that your method (method = formula) for setting up BBC is useless. Atleast those calculated number is meaningless. Your method work only with assumption that zero BBC has zero braking force. The car static weight distribution should only be used as hint not to be derived into spesific BBC value, this is what I am thinking now.

    About proof, you don't have proof wether zero BBC in setting screen have zero brake force either.

    About unexpected result, are you saying that a very stiff front and very soft rear in GT4 can result in not only oversteer but it can result in understeer too? This need to be tested. But I have a feeling that you are wrong. I believe that a very stiff front and very soft rear will only result in oversteer in GT4. But I will be very glad if you can give me an example where car will understeer using it. If you can't I will assume that extreme tuning will give expected result. And spring rate in GT4 have reverse traction effect too.

    I don't think using a proper everything else will change the way spring rate behave. I do not believe that using 1/1 1/1 damper will change extreme spring bias behave when using 10/10 10/10 damper. If it oversteer it will still oversteer.

    I am guessing that a very stiff front and very soft rear in RBR will not give unexpected result too, it must be understeer.

    About pop, I guess pop is the correct word, although I prefer improve. every play is learning. Still use many of my pop tuning. drop some of it too.

    About rubish, I don't see any test about it in GT4 yet. Do you ever compare extreme soft and extreme stiff spring rate laptime? Please post it.

    Those claim come from deriving extreme spring behaviour. Or you have better explanation of what make the car oversteer when using a very stiff front and very soft rear? My explanation is because the front receive more traction than the rear if we do that.

    about spring as stiff as possible, it can also mean avoid using lowest spring rate if possible.

    about TCS, ok.

    about undrivable, agree, skill have influence.

    About 300mph, drag racing and top speed race is part of GT4 physics engine, everything that work in there have influence either big or very small in normal race too.

    BTW, if you have interest you should update your 300mph entry, it is bellow average now.

    About special feature, I don't said it will make the car handle very well, I said it will make faster time. Special feature exist because GT4 has flaw. Spesific rule exist to make the program easier to code. It will need a very complex code and expensive hardware to make a simulation close to perfect. With cheap console, there has to be compromise. This flaw or compromise is the special feature I seek.

    I find it noble that nobody ever try to apply the GT4 quirk in a race, play fair mind. I usually do my work with shortcut, it make me work much faster. I would be slower at first, but in the end I am faster. I like to do this in game too, GT4 is no exception. Just like when I attempt 300mph, 6 hour for the first car, now I can do it 30 minutes from equiping the car to making screen shot. Sometime, those 30minutes will result in 1st position. Finding shortcut need more time, but if we can find it we can make something faster.

    Let me do weird tuning, if it end up bad, critisized me. Even a bad example can be used as lesson to everybody else too.

    Teamm666, I think the problem is my skill, with my current skill I will still feel safe using an extreme setting. Like in my recent viper (no TCS), 1'39 is the average time I get with some screw up somewhere. This is also why I am very happy when there is GT4 setup judging at last, judge can give feedback to what my setting lack that I can't detect.

    Is BMW 320i Touringcar a bad car?

    Things that can be learn from 300mph that can be used in track is things such as power/tourqe relation to acceleration in different gear ratio, empty balast behaviour, high front height, better roadcar front traction in corner, low speed spin relation to high speed traction, downforce wind resistance at low speed and high speed, huge camber corner traction, etc.
     
  25. Scaff

    Scaff Staff Emeritus

    Messages:
    24,462
    Location:
    United Kingdom
    Sorry to be so forthright about this, but buy a better controller then and learn to drive consistently with it.

    Until you are able to actually feel what is happening with the car you will be at a disadvantage both driving and tuning.

    Using static weight as a starting indicator does not mean I tune just by formula, it’s a starting point and I make it quite clear that it should be used as a guide to work from.

    Dampers is a subject I am not going to open in this thread, safe to say I don’t and will not agree with you, as far as I am concerned it’s a major flaw in your ability to tune, and your refusal to accept that (by your own admission) the limited feedback you have may be misleading you.

    Nice to know on the spring rates that you have at least taken on board previous conversations; but rather disturbing that you are again trying to put words in my mouth. I am the one who has always maintained that you can’t judge spring rates from just visual information.


    My calculated method is far from meaningless and I am extremely insulted by the comment.

    I would ask exactly what you base that statement on, as my method is the result of the adoption of real world brake bias set-up and countless hours of testing the braking physics, performance and set-up in GT4, looking not just at the BBC, but racing brakes and the effect of tyre grip as well. The evidence is well documented in this thread, I strongly suggest that you read it and put in place constructive criticism, with evidence before you make a statement of that nature again. Particularly given the quite frankly appalling brake set-up on your 350z tune I find it quite amusing that you make this claim.

    The issue of zero brake force has no effect what so ever on my (proven and documented) method of tuning the BBC, please explain in detail and with proof why it should.

    Your comment on static weight distribution and its effect on brake bias setting also shows a limited and potentially flawed understanding of the subject and also that you have not either read or understood the piece I wrote. A piece that quite clearly show that the static weight distribution is a starting factor in calculating brake bias setting, and also a considerable factor in the accurate set up of brake bias.

    I would ask what professional experience in brake set-up and the physics involved do you have?



    Invalid point, I’m not the one making the claim, you are. Don’t answer a question with a question, just answer the questions. How can you prove what you claim.



    Good to see that this is based just on your feeling rather that any documented evidence, convinces me no end.

    It has been tested, by a number of people, the results of which have been documented here in the ‘Is GT4 spring tuning reversed’, the general opinion is that it is not, but that extreme values do (as in real life) have unexpected results on the cars handling balance.

    I will dig out the exact Skip Barber* (done see the foot of the post) info tonight (it will nice to see you claim you know more than him again), but in a nut-shell if you soften one end of the car too much you can push the alignment out and have a very negative effect on the tyres contact patch. You mess up the contact patch and you lose grip, not gain it.

    To be honest almost all the ‘evidence’ regarding reversed spring rate tuning is based on the use of extreme values, rather that a gradual increase and decrease to see the subtle shifting of balance. This I have done, and the results of the work are my tuning guides.



    Which only goes to illustrate the very basic and flawed understanding of what is going on with the car, you are claiming that going from a soft and very unrestrictive damper to one which will both limit the spring itself and change how the tyre (and therefore contact patch) remains in contact with the road will have no effect on the cars balance?

    That is quite simply an incredibly naïve approach.




    I have pointed out sources on this above and explanations as to why it can occur, as mentioned I will post the Skip Barber info tonight* (done see the foot of this post).



    I don’t dispute that its all part of the GT4 physics engine but the effects of downforce, aerodrag and lift above 200 mph have very little or no impact on tuning a car for the average track. These areas (at this speed) are very poorly modelled by GT4, but are not going to effect how a car behaves in a second gear corner.



    I have no massive interest in keeping testing for 300mph runs, I’ve done it, but the flaws in GT4 (as discussed above) make it less interesting to me.



    I have not disputed that flaws exist in the high speed physics, that’s not exactly new news. However just because you can do it for something as simple as a high speed run on a single track, does not mean that you can do it for circuit work and every car on every track.

    Take one of your set-ups to the ‘ring and top out at 300mph on the main straight, without the tyres loosing contact with the track surface. I don’t recall you doing this, that would be a step in the right direction to saying you can use even this ‘quick’ set-up on a range of tracks.

    So far all you have shown is that high speed runs on a single track share similar set-ups, that’s a bloody long way from a magic setting that will give the quickest lap times for every car on every track.



    I don’t disagree. The problem is that you do not seem to be able to learn from your own bad-set ups. You are claiming that the reason the 350z set-up did not work is because GT4 is at fault, rather than your own set-up.

    Have you even tried any of the other set-ups yet?




    I’m sorry but a car set-up for high speed runs will be very different to a car set-up for track work, and while you can learn about how the car behaves you certainly can’t directly apply it to circuit work.


    Regards

    Scaff


    Edited to add the quotes I discussed above regarding the problem of loss of grip caused by spring rates being set too soft.

    And another warning on the problems that can be encountered from setting a spring rate far to low for the car.

    So what was that you were saying about softer spring rates always increasing grip at that end of the car?

    Up to a point yes, it will, but at the extremes you start to run into unexpected results. It is perfectly possible for a spring rate that is too soft to result in a massive loss of grip rather than an increase in grip.

    That’s the problem with jumping to extreme settings, and that’s why I do not use them.
     
  26. sucahyo

    sucahyo

    Messages:
    2,171
    I revisit what you said earlier that "What it (TCS) certainly does not do is change the brake bias". Do you test it again? or just base it on your single car test?

    about meaningless, cool down, I don't mean to ignore all your countless hour, the result of those is what I disagre. I don't have profesional experience, but I don't think it make any different, GT4 is not that perfect, not all real life experience can be applied when tuning it.

    about BBC, it's not how it works that I said is useless, the number that calculated from dynamic weight dist is useless.

    From your guide:
    "With car A above I would try both 4/1 (80%:20%) and 5/2 (71%:29%) to see which one worked best."
    "With Car B I would try 5 / 1 (83.3% : 16.7%) and 6 / 1 (85.7% : 14.3%)"
    "As has been discussed above the brake balance controller does not just control the ratio, but also the level of force applied"

    This is what I understand for Car A:
    1- 4:1, 4 is for front brake, 1 is for rear brake.
    2- front brake supposed to have four time stronger brake force
    3- 4:1 is the value that the brake physics engine has to simulate

    For the above to be correct, this should be true:
    1- BBC 10 is ten time stronger than BBC 1
    2- BBC 0 means no brake force at all
    3- the value displayed in setting screen is the actual value used by physics engine without any addition.

    In GT4 I feel number 1 is wrong, and highly suspect that number 2 is wrong too.
    In GT2, number 2 is wrong (hacked it, what else) and brake power has no relation to dynamic weight distribution at all (tested about 8 car, 8 BBC combination).

    By only using those limited range, you are omitting the possibility of weird behaviour. maybe cause by controller or by programming mistakes. IMO, now, to get an optimum braking we should experiment every BBC combination for every supension change.


    Still stubborn about 300mph influence in normal race. 200 mph still a bit infected.

    About my car bad because GT4 quirk fault, no, I will gladly use any GT4 quirk, just being surprise, learning and don't have much time. I'ts entirely my fault. Don't have a chance to test other setting yet.

    about unexpected, if it always oversteer, don't call it unexpected.

    About skip barber reference, I use 7/17 in my Opera 350Z. I don't really think 7 would give rolling problem that much. I don't take that quote as saying front and rear spring ratio, I take it as saying if we soften spring too much, it will create roll, and more roll is bad. Pairing my setting with 7/1 stabilizer will make the understeer far worse.

    the opposite, I am saying GT4 spring rate unrealistic.

    I am increasing it, not lowering it. They don't talk about the ratio/bias between front and rear either. 7 Spring rate in 350Z is not too soft. If you say extreme, it is my 17 rear spring that is too stiff. Any reference about using spring too stiff?

    So, you really don't have example of car that will oversteer using 7/17 spring rate?
     
  27. Scaff

    Scaff Staff Emeritus

    Messages:
    24,462
    Location:
    United Kingdom
    Its based on a number of repeated tests over a number of different cars and tens of hours of testing in GT4 on braking systems alone.



    Firstly I did not say that 'real world' theory could be applied directly, I said that my method had been adapted from real world theory. You need to read things more carefully.

    Secondly I have never said that the end result of the calculations can be used directly, I say it will give you a sound starting point, and that you should then test from that base.

    I also know for a fact that the method is sound, as I have carried out tens of hours of brake testing to put this together and ensure it works. The results of most of which is avaliable for anyone to read in this very thread.

    Why the hell should I calm down on this one, how about you instead back this up with some evidence of your own as to why I am wrong. Rather that once again just throwing down your own pet theories with no evidence to back it up.

    How long exactly have you spent testing brake bias set-up and its effects in GT4? What documented evidence do you have to discredit my methods?

    Because to be blunt you should either put up or shut up.


    Be as stubborn as you like, you normally are, but again show some proof rather than just giving us your ideas and pet theories.

    I also did not say that your car was bad because of any quirk in GT4 (I said that you talked like that was the case), your car is bad because the set-up is poor and ill considered.



    I don't recall saying anything was always oversteer?



    The Skip Barber & Allan Staniforth quotes were in regard to your statement (once again as fact) that extreme spring rates will not have unexpected results. Quite simply you are wrong on that point.

    First how do you know 100% that under maximum braking (maybe of around the 1g order) a spring rate of 7 is not going to be overwhelmed or at the very least hit the bump-stop.

    Even discounting that a set of front tyres is only capable of handling some much work, and under heavy braking and steering will understeer.

    However above and beyond that I have always said that the problem with your set-up in this regard is the damper set-up (which is why I have not directly referred to the 350z in relation to those quotes), an overdamped set-up would quite easily explain the issues with the car.




    See my above piece on this, and yes they do talk about too stiff spring rates.

    They do also quite clearly (seems you are once again only reading what you want to read) talk in the Skip Barber piece about grip at a single end of the car, and the Stainiforth piece is talking about single spring corners!!! So youre statement that they are not talking about the front rear bias is not only incorrect, but selling the Stainforth piece short. Once again please read things more carefully before posting.

    You also seem to mention in your quote that you now believe that spring rates in the entire GT series have the opposite effect to how they should react in the real world. So PD got both dampers and spring rates wrong did they?

    I was also not aware that you actually had GT3.


    What are you talking about? A real world reference?

    I don’t recall you asking me for an example of this, rather you said that extreme spring rates would not produce unexpected results.

    I have carried out hundereds of hours of testing on GT4 and as I quite clearly state in my guides, softing one end of a car will increase grip at that end to a point, after which grip may be reduced. In reagrd to stiffening a spring it will generally reduce grip at that end of the car.

    If this causes under or oversteer will depend on what is happening to the car at any given time.

    I would add that I stand 100% behind what I have put in my guides, they are the result of extensive testing in GT4, and have been used and the results confirmed by many, many people. I used my methods to put together set-ups for BESTuners, set-ups that gained a lot of praise from people who tried them.

    However I am yet to see the same in GT4 from you?

    What documented evidence do you have to put forward to be checked (as I have done with everything I say) that supports your claims. As with your damper theories, the answer is none. Yet you see quite happy to say that checked and tested methods are wrong, without offering a single piece of counterpoint evidence.

    Regards

    Scaff
     
  28. sukerkin

    sukerkin

    Messages:
    2,063
    Sucahyo, I've kept quiet on all of these 'tuning' related threads for quite some time.

    But I think it's time that someone, without hostility, spoke up and gently pointed out the following.

    No matter how often it is brought up that a certain aspect of GT(n) doesn't work according to Real World physics, the fact will remain that it is a game and not a simulation (altho' PD might like you to think differently).

    As an approximation it is fine and is much better than it's competitors but that does not mean that in all circumstances you will get the response that automotive engineering would lead you to expect. In the main tho', all the principles that I've taken years to learn in the real world do apply with a high degree of correspondance in the game.

    Taking that as a given, it is also the case that constant play utilising a controller that gives you at least some degree of 'feel' and feedback from the system confirms the initial impression that, with some allowances for bias in the code, all the major tuning algorithms coincide well with what you'd expect, particularly the dampers.

    Now to give this opinion some weight, you have to bear in mind that until I settled down a couple of years ago I spent more time researching and tuning in GT than I did in my job :O. That translates to the sad fact that I'd spend eight or ten or twelve hours a night, tuning and racing cars in the game.

    In the most non-confrontational or derogatory manner possible, I have to tell you that in all those thousands of hours I have found no evidence to support some of the points you are postulating.

    If you add that to the huge weight of counter-opinion that has greeted you on every occaision that you have tried to 'argue your corner', so to speak, then it must be time for you to reconsider your position.

    If for no other reason than because of the simularity in our user names, some members have mistaken me for you and given me a right good flamming {:lol:}, I beg of you that you desist in this futile promulgation of flawed conclusions (at least until such time as you have gathered together the appropriate equipement for you to assess properly the effects of the changes you are trying-out on your cars).
     
    Scaff likes this.
  29. sucahyo

    sucahyo

    Messages:
    2,171
    about TCS, Ok.

    about BBC, you still don't get about what I mean, but since I know that nothing can change your opinion, I prefer to stop arguing. Good to know that you spent tens at hours at it. Some suggestion, I think you should reduce the repetition to increase variety, 6 time for 1 test is a bit overkill, better use it to test more car.

    If you still have some hour free time a day, you should test the effect of each suspension change to the way car braking react. It is better if you the one that posting it, since you the one that create this thread. It's a bit sad that no one else seem interested in doing this, since doing this kind of testing in GT4 is easy and fast (data logger).

    about unexpected result, please don't call the result of a very stiff front spring and a very soft rear spring unexpected, it is always oversteer. What so unexpected about it if it always predictable. Put it on MR, RR, FR, FF, 4WD it always result in more oversteer. Can you use the word unexpected if the result is predictable.

    In GT4, if I put a very stiff front spring and a very soft rear spring, I will expect the result will be more oversteer. And it always turn out more oversteer. Everytime I use it I don't say: "Wow it is unexpectedly more oversteer, it has unexpected behavior just like real life!" over and over, I will say: "well, it is more oversteer like expected" everytime.


    If it turn out that puting a very stiff front spring and a very soft rear spring can also result in more understeer, I will put my apologies in my signature. But I don't think there is a car in GT4 that will be more understeer using this setting.


    about GT3 I read it in forum. Although it's interesting to play GT3 since it has MKprogram to play around with forbidden setting, I don't intend to play GT3 as some don't believe GT3 has some same behaviour as GT4. Any test done in GT3 will be useless.

    About real life quote, are you saying that using extreme soft at one end can make it loose grip more And 7.0 spring can be considered too soft so this will end up loosing grip because of rolling and bottoming at default ride height? Ok then, I can accept that. You prefer to call 7/17 as softening the rear? ok, I can accept that.


    Sukerkin, ok, I guess I should post some test result before posting something like this. My opinion for BBC comes from many hour of brake testing in GT2. Unlike Scaff, I believe GT2 tuning have similarity to GT4. A bit of clue is found by hacking, since hacked tuning is unaccepted in GT4 section, I guess I should find another way. I just notice spring rate recently.

    My way of testing usually different than many of you, I never see anyone else bother to test how many smoke a bit stiffer spring rate has when braking :) (a lot less). I found it interesting and I like to do something like this in GT4 too :).
     
  30. Scaff

    Scaff Staff Emeritus

    Messages:
    24,462
    Location:
    United Kingdom
    I get exactly what you are saying; I don’t however think it is relevant.

    My method is based on proven testing, clearly laid out for anyone to try, I know it works. I’ve also had many others try it, use it and find it worked. In the Nurburgring racing series my method of BBC set-up made a huge difference to some of the drivers.

    In now appears from your comment below that you base your very negative comments on your experience with GT2, which has a totally different physics engine. Additionally you have still failed to actually provide either some evidence to disprove my method or an alternative method of setting the BBC. You also seem to forget that I have direct experience of how you believe the BBC should be set, and to be candid I was not impressed.

    I will repeat my statement of my last post.

    Put up some evidence or proof or shut up.



    What a great idea, add in a huge amount of variables and remove the method that ensures one-off or anomalous results are identified and removed.

    The only thing that your suggestion will do is result is less accurate testing. Way to go.




    Doing this kind of testing is not in any way easy or quick, I should know I’ve done more than enough of it in the time I have had GT4.

    I am currently extremely busy, and for anyone with a basic understanding of how and why load transfers during braking will have a idea of what to expect.

    In the hundreds of set-ups I have done in GT4, as long as I have not used the laughable extremes that you have a taste for, I have been able to ID what changes have been needed and make them.




    Exactly how many cars have you tuned in GT4?
    And how many of them were not for 300mph runs?
    How much time have you now spent with GT4?

    The reason I ask is that in the hundreds of cars I have worked on and the hundreds of hours I have spent on GT4 I can quite clearly say that the one thing extreme settings do results in is a very unpredictable car and very often unexpected results.

    In a similar vein I have asked you before to stop just using the term understeer or oversteer, it’s just far too simplistic. To discuss in any serious way you need to clarify when it is occurring, something you have patently refused to do.



    NO IT DOES NOT

    To be totally blunt if it were not for the screen shots and photomode stuff I would actually seriously doubt that you actually had GT4. As it is it seems that you have a very limited ability to interpret what a car is doing and an even more limited ability to convey that to us.

    Again you have (despite being asked on numerous occasions) failed to actually say when this is occurring, oversteer when?



    Take a front wheel drive car, leave all the other settings alone, stiffen the front spring rate and soften the rear, zero all the driving aids and leave everything else alone.

    Drive at top speed towards the first corner at Grand Valley, apply full brakes and then try and apply full steering lock.

    And what do you get? Thats right, understeer.

    Plenty of cars in GT4 will react like this, I just serious doubt that you have any where near the time on the cars to actually full appreciate this.

    Ok I have actually tested this with a Clio 2.0, fitted FC suspension. A gradual increase in front spring rate alone (to begin with) resulted in a slightly better turn-in, but an increase in on-throttle understeer, particulalrly in contant radius cornering and corner exit. The same effect can be felt to increase as you raise teh front spring rate, right up to the maximum.

    I then set the rear springs as soft as they would go, the result was no reduction in understeer (in the situations described above), but a markedly unpredictable behaviour pattern off the throttle, particularly during moments of rapid load transfer.

    So we have a car with very stiff front springs and soft rear springs that understeers under hard braking, through constant radius cornering and on corner exit, all at an increased level from the default and all far more that with a descent set-up.

    For interest I then ran my prefered set-up (which can be found in teh BESTuners thread, a much more 'conventional' set-up that was a good 4 seconds fast around Tskuba than with the 'extreme' set-up from above.



    Then why did you mention GT3 reacting like this as if it were fact?

    I’ve warned you about this before and consider this another warning. Stop posting opinion as if it was fact, if you are quoting a source (as in the GT3 case) that you need to quite clearly say that.



    Yes I am saying that extreme soft at one end can make that end loose grip, not only am I saying it, but so are Skip Barber and Allan Staniforth.



    I do not recall saying that at all?

    I have asked you politely in the past to not try and put words in my mouth, you don’t sem to want to listen. So I’m no longer asking, I am telling you to stop doing it.

    I did not say or even imply that at all.



    Your opinion on how GT4 BBC set-up should be done comes directly from GT2, great stuff.

    Does that mean that you have not actually tested this in any meaningful way in GT4? Again great to hear that you have dismissed my hours of testing, documentation and evidence based solely on how the BBC functioned in GT2, a game with a different physics engine.

    I’m beginning to get to the point at which I have to question your motivation, as it simply seems to be to disagree with almost everything anyone says.

    You have failed to learn at all from the countless number of times you have been wrong, attempt to make out that people have said things that they have not, dismiss work done by people based on your own totally unproved theories.

    You dismiss real world evidence out of hand and claim it to be incorrect (sometimes based on it not containing a single specific word), then when it suits you try and claim you had always agreed with it and that other people said it was wrong. Most amazingly you have tried this on a number of occasions with me, with quotes that I supplied in the first place. I find it rather disconcerting to believe that you consider me that stupid.

    In addition to this you have a chronic habit of posting your own theories as fact, without any supporting evidence or testing.

    When you question others and say they are wrong, they (and this is far from just me) have provided countless repeatable tests to back up what they say. When other members then duplicate these test and get the same results, you simply dismiss what they are saying as wrong.

    However when pushed to provide any documented and repeatable evidence you fail on every single count.

    You seem to forget that I have seen the feedback that your GT4 set-ups have attracted, and apart from the 300mph ones (and some of these have been questioned), the general consensus has not been good.

    I’m sorry but you are trying to lecture a number of proven tuners, yet the only track tune you have yet provided to us was quite simply one of the most ill conceived and flawed set-ups I have ever seen.

    You have the gall to question my methods of tuning and my understanding of GT4 tuning, when your own attempt required TCS set at 10 to get even close to driveable, and even then it most certainly was not quick.


    I have to say that you should consider the last part of this post as a warning in regard to your posting style and its content. Any further attempts to twist what other members have said or post opinion as fact will result in an official warning. This is after all not the first time I have had to pick up on these areas; I certainly hope that it will be the last.

    Take on board what has been said to you in regard to tuning (remember its not just me) and actually spend so time tuning (with a decent controller) before you start to come here and state that we are wrong in everything we say.

    Scaff