Tuning Garage Links & FITT Physics Discussions

Discussion in 'GT6 Tuning' started by Motor City Hami, Nov 30, 2013.

  1. rams1de

    rams1de

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    To reduce oversteer on corner exit on RWD I go through the following tweaks in small increments:
    Reduce LSD Accel
    Reduce LSD Initial
    Create some rake - Raise rear RH/Lower front RH or Raise front RH/Lower rear RH (getting inconsistent results)
    Increase positive rear toe
    Lower rear Damper Compression
    Lower front Damper Extension
    Lower Spring Rates in proportion
    Lower rear Spring Rate
    Ease off the gas
     
  2. Zuel

    Zuel (Banned)

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    Are these low LSD number being used on race or street tires?
     
  3. BlueShift

    BlueShift

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    I disagree on most things because I think there's a maximum after which you loose the effect you want.

    Exemple : say your front RH can go until 30mm. Until 60mm it gains grip, and after your ride hit the road, you loose grip. There's same effects on most things you tell.

    On spring rates, you tell:
    "Spring rate - lower front, higher rear increases front grip" - it's not grip as I use grip, it's road adaptation. You make the front loose, so the vibrations of the engine + road + accel + decel are smoother. The LSD will lock less but somehow that's the "grip" you gain. With a good setuped LSD you even loose grip.

    You have all the weigth in the front. You won't be able to hold a raceline in wider curves, I think doing this will make you hit the external barrier a lot at lower speed that if you have balanced spring forces according to the weigth distribution : you loose grip there.

    I think you could investigate with some formulas I use a lot esp on FR, MR and RR.
    - (ext level / comp level) * spring rate
    Do this for front and rear. Check if the numbers are still balanced due to the weigth distrib. That will get you sometimes strange results, but mostly great results.
     
  4. BlueShift

    BlueShift

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    I guess they should be IRL. A tire loosing traction = lsd lock no matter the levels. You don't want the grip tire to spin like crazy in these cases.
     
  5. donpost

    donpost

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    156
    Hi guys, I've done some research on the diff/tyres and I guess this is the place to put it.

    I wanted to see if tyre selection impacted the correct accel setting on the diff. The "right" setting is the one just high enough to stop the inside wheel spinning first - which I think is the method 99% of people use. In this case I was using the skid pan at Willow Springs to ensure I was always tuning under the same conditions.

    I found that on the car I tested a setting of 19 was required for racing softs, however on a set of sports hards the correct setting was 13. This is what I expected as grippier tyres => you can pull more lateral g => more weight transfer => more torque transfer required => a higher diff setting.

    It was also interesting to note that the correct setting was very sharply defined on the racing softs - i.e. a setting of 18 was clearly too low and a setting of 20 was clearly too high. Whereas, on the sport hards the setting was "fuzzy", that is to say there wasn't much difference between a setting of 12, 13, or 14. In real life softer/grippier tyres tend to have a narrower peak range of slip angle/ratio than less grippy road tyres. It's pretty cool to see this implemented in Gran Turismo.



    I was thinking it may be possible to do some camber testing using the diff, by taking a RWD car and seeing if changing rear camber affects the correct diff setting. The amount of camber that results in the highest diff setting is the one that provides the most cornering grip.
     
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  6. ace004

    ace004

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    I have also found the lsd settings on most cars with sh tires to be between 12-15.
     
  7. Zuel

    Zuel (Banned)

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    The highest got on the diff with sport hard tire RR 11-21-25. I'm not sure how well it will work with FF, 4WD should be fun to setup. I'm a little hesitant to try this on any of the MR or RR due to they are over turning under braking and acceleration.
     
  8. praiano63

    praiano63 Premium

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    I was suspecting a few weeks ago that the red and white strips in and out a curve had a superior grip and that was inducing oversteer when the front inside tire was passing bove it cutting the apex.
    I did a test a few minutes ago that shows this very well.
    It`s not only the red and white part but also the escape area out the dangerous turns like in suzuka 1st and second turn or in the spoon curve.
    Take a powerfull RR MR or FR and go on this escape area with a sport hard tires or less grippy one.
    Try to burn some ruber doing some standings starts full gas.
    Nothing happen ,even when you try to do some donuts. This is no problem because this area is very eficient and do his job very well when you go out of the road.
    The problem is that the red and white strips have exactly the same grip level and behaviors than this escape area.
    Try now to burn the rear tires puting one on the red white strips and the other on the track. You will see that the tire who stay on the track spin burning rubber. This is why when you pass over it cutting the apex at the grip limit of the other 3 tires, this sudden excess of grip can make you spin easy. The correct level of grip of the strips would be less than the track , the exact way the paint do in the real life.
    This is an important point that PD need to correct urgently.
     
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  9. donpost

    donpost

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    So wait - the paint has MORE grip than the track?! What track did you test on, or is it the same everywhere?
     
  10. jtqmopar

    jtqmopar

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    The off-track areas have a power limit, where you can easily spin out and lock up the brakes on them, but you can't burn out there. Try braking without ABS at the Indy strip, then spin out in the back section, and see what happens
     
  11. donpost

    donpost

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    156
    If that power limit is on the kerb too then you might be able to slingshot yourself around the corner at higher speeds by putting your inside wheels on the kerbing.
     
  12. praiano63

    praiano63 Premium

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    Indy strip first meters is like an ice ring, escape area are different and they are ok to contain the speed. All the red & white kerbs any track have a superior grip, at least the fact you can´t spin a tire on it show that there is more grip there. This is a real problem whith racing tires when the front inside tire pass on it. This excess of grip at this point make the other 3 with less grip pass over it and spin in certain situations like weight transfer due to driving input at this moment. You can check this easy with the BMW Z4 GT3 '11 or the AUDI R8 LMS ULTRA
     
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  13. jtqmopar

    jtqmopar

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    I was referring to the "feel" of sudden TCS in the off-track areas
     
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  14. Hasassin_X

    Hasassin_X

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    Hey guys,

    I'm new to the site but a veteran when it comes to GT, with that said one of my cardinal rules is to test drive the car bone stock after adding parts. This will give you a good feel for how the car feels and let you make tweeks based on your feel for how you drive the car. I've used tuning calculators and others tunes which work for the most part, but the key to remember is no tune can make a car drive. You are the driver and you control the car, no tune can drive the car for you. I'm going to try and post some tunes ASAP. I'm not a tuner but i do think i have a grasp on it for how i drive and have every gold medal so far in the races both mission, seasonal and in career. I play with all assist off except ABS at 1 working on taking it off but i play with the DS3 so its not that easy. Hope this advise helps you guys out and videos of my races and some tunes coming shortly stay tuned.
    :cheers:
     
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  15. MrGrado

    MrGrado

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    To go ABS:0 for the first time you will want to bring your braking points back a little and be light on the brakes. You need a little more margin for error but if you start to get the hang of it, you will more than likely enjoy it.
     
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  16. Hasassin_X

    Hasassin_X

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    Yeah I currently have it set on most cars to 2 or 3 in the front and 2 or 3 in the rear. This is because I brake late in corners for that extra edge, taking it to 0 means gonna have to break a bit earlier..lol thanks for the advise
     
  17. Zuel

    Zuel (Banned)

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    Running without ABS is a joke @Hasassin_X, applying the brake half way or not even half way is pointless and it doesn't even teach you proper breaking. Yes it can be challenging but it's pointless. I've ran many of cars without ABS and they've never locked up before getting to full break. The brakes without ABS are garbage in GT6 just ass they were in GT5. The braking physics need a lot of work in GT6. Running with no ABS is going to slow you down in some cases in breaking. I run ABS at one and I'm still getting brake lock up.
     
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  18. Ridox2JZGTE

    Ridox2JZGTE

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    Not really physics, but more to interface issue ( in game input parameter - sensitivity + force applied ), PD needs to tailor every wheel/pedal device to suit the game ( allow full pedal travel when brake assist disabled ). Even on stick controller, DS3 and DS2 are like night and day when using face buttons for brake and gas.
     
  19. Zuel

    Zuel (Banned)

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    I really doubt it's a interface issue @Ridox2JZGTE. There are other games and sims of lower quality that have done a better at simulating braking with no ABS on gaming console, Super V8 is just one of those games. It's a matter of correcting the software code to the correct effect. Coding has nothing to do with interface.
     
  20. Ridox2JZGTE

    Ridox2JZGTE

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    What I meant is PD programming the input data from external device to the in game physics system. The DS3 square button for example, has low range pressure and input, while the DS2 has 3 times more range and pressure, this alone allows racing brakes at 9/7 BB without ABS. This differences helps, but the best fix is allowing the red brake bar ( force ) to have more play ( rise higher ) before locking up - less sensitivity could help, say for example when racing brakes kit fitted and high brake balance - half pedal travel equals to 25-35% red brake bar on HUD, the deeper the pedal the more progressive it rises ( more than 40% usually locks ), so with lower BB, you could have more pedal play before lock up.

    With user adjustable pedal sensitivity - dead zone - and travel in game, that would be enough to make no ABS enjoyable.
     
  21. Zuel

    Zuel (Banned)

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    Brakes without ABS would not even lock up at 40% break power, the most I've seen on a real car or sims or game of lesser quality break lock up occurred at 65% front break or higher if you really put force on the brakes. You can even lock up the brakes on a bloody Kart and they have the best braking force in the world. In GT6 the breaks can even lock up on a Kart. So how can you truly believe interface has anything to do with it @Ridox2JZGTE when the only thing PD has come close to date in physics in GT6 are the tire and suspension on a few cars? They are a number of cars that are still off in so many ways but there are a large amount of cars that are true but no one would or will really know due to they're stuck in GT5.
     
  22. Ridox2JZGTE

    Ridox2JZGTE

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    IMO, the brake balance are numbers that represent value for brake force and how sensitive to input, if PD reduce overall brake force applied in any given input state, would that help to solve easily locking up racing brakes ? For me normal brakes are fine, I can apply full brake with almost no lock up using low BB value on some cars. Also, be sure to test brake balance + no ABS in arcade races, this is the only place you can be sure the brakes works, pick any car and tire, try 0/0 on normal brakes, then 10/10, then install racing brakes, 0/0 and 10/10.
     
  23. Zuel

    Zuel (Banned)

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    LOL, not to be rude but you explaining brake bias to me is like someone explaining physics to Einstein. There is no reason explaining something to me that I already know to well @Ridox2JZGTE. The brake physics in GT6 are awful, really awful. I've tested the 0/0 brake bias along with the 0/0 camber and both are a joke due to the coding was done incorrectly. 0/0 brake you should have nothing, peddle to the floor a dead peddle, "I really hope some of you know what that meant" also 0/0 camber you have nothing but for some reason both work for now. I really don't understand why the braking has to be along the lines of GT5.
     
  24. BlueShift

    BlueShift

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    It's not brake strength, it's brake bias.
    0/0 is the same strengh as 1/1, 2/2, 3/3 or 10/10. The only difference is the attack of the strengh, low is smoother somehow.
    0/1 mean 100% rear. 1/1 mean 50%/50%, as 10/10.
    4/6 mean 40%/60%, as 2/3 but will brake at max strengh faster than 2/3, that 2/3 will also brake at the same max strength too but a little slower than 4/6.
     
    Last edited: Jan 17, 2014
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  25. Ridox2JZGTE

    Ridox2JZGTE

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    Ok, you are smarter than me :) At least for now, I have no issue with no abs braking, running 9/5 BB on my race brake driving Diablo GT2 or 4/10 on the R8 LMS Ultra Phoenix. I have tried G27 on GT6, same setup and BB, I adapted quickly, but the pedal was modified. I am used to drive with limited feedback on a stick - braking with my thumb, so braking with pedal and muted sound is still doable for me - better than my worn out DS2 stick.

    You have to try all your cars in arcade races, the brake balance works 100% there, unlike in online or test drive ( buggy ). Some cars even with rear bias can still be driven well, my R8 is an example - 4/10 BB in arcade races :)
     
    Last edited: Jan 17, 2014
  26. BlueShift

    BlueShift

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    Rear bias is almost always a good thing...
     
  27. Zuel

    Zuel (Banned)

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    Have you dealt with a car with 0/0 bias @BlueShift, do you know what a dead peddle feels like? 0/0 bias is a dead peddle no pressure at all. Yes you may get some force along but not the correct force needed to stop the car. I was going to add something but it's pointless. I'm not sure if you've been a car where you're able to adjust the bias or not but from from MY pass expenses 0/0 bias is a dead peddle.
     
  28. iainoflo85

    iainoflo85

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    I used to think that, but I've recently been favouring a front bias on FR and MR cars. FF still needs to be rear heavy.

    GT6 is not Real Life. So no matter what your past experience with real cars it will not always translate to Gran Turismo (which is still a game).
     
  29. BlueShift

    BlueShift

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    Maybe irl but not in GT6... They considered same numbers / same number mean 50/50. x/0 mean 100% front, 0/x mean 100% rear and x/x mean 50/50.
    I'm not saying it's a good thing or not, it's how it's done in GT6.

    Why you'd ever want to run at 0/0 anyway ?
     
  30. Zuel

    Zuel (Banned)

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    I see Gran Turismo as a tool rather than a game @iainoflo85. It may be the mindset that I have compared to others. Mindset tells a lot about someone.


    I don't use 0/0 bias @BlueShift, and using it is pointless to me along with the other new methods.