Tuning to reduce lift-off oversteer

Discussion in 'Gran Turismo PSP' started by peterjford, Nov 1, 2009.

  1. peterjford

    peterjford Premium

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    I have never been very good at tuning, but I understand some of the basics. I have searched for a tune for the Audi R8 LMS and the Lotus Elise but haven't found anything for the PSP. I have read the guide here and it seems the only way to minimize lift-off oversteer is to increase rear toe-in. Is there any other things I can do with the minimum tuning available in GT PSP to help tame the rear end of cars like the Audi R8 LMS and the Lotus Elise?
     
  2. SiNiST3R

    SiNiST3R (Banned)

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    What your experiencing is the behavior of Mid engine cars.

    Its a tad tough to get used to on those cars, I would practice in a NSX for a bit.

    You will never tune that out of the car, its the behavior of the layout. Unstable is faster, kinda like the principle in fly-by-wire jet planes ;)

    Your best bet is to familiarize yourself with the layout, and tune afterward.
     
  3. LeChittie

    LeChittie

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    I know what you mean buddy, I have the same problem with all mid engine cars,
    Try being more gentle on the throttle next time =)
    That should help you out :D
     
  4. NLxAROSA

    NLxAROSA Premium

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    Like said above, MR cars behave like that. Rather adapt your driving style (e.g. don't lift off in the wrong places ;)). However, I find the R8 LMS quite manageable if you max out rear downforce.
     
  5. allent2

    allent2

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    I know you already heard about this but I've found that most cars have a rear toe setting of +0.20. Toe out like that is when the font of the tires are farther apart than the rear of the tires as veiwed from above, like this ' \--/ ' that will make the car more resposive but as youve found expesily in MR and RR cars will overster very easy. I would try to zero out the rear toe or even a tenths in the negitive direction. But yea downforce can play a huge part in keeping traction aswell!
     
  6. CaptCalvin

    CaptCalvin

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    This information is actually incorrect if the description of the rear toe in the game is to be trusted. Positive means toe-in ,while negative means toe-out.
     
  7. SiNiST3R

    SiNiST3R (Banned)

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    The definition described in the game is accurate, to be trusted, and why wouldn't it. There was allot of confusion over this in GT4, the terminology can EASILY be confusing, as people usually equate the positive and negative indicators to reflect the distance between the front of the tires. In GT4 it wasnt made clear in the scrolling text, but in GT PSP they fixed that by fully explaining it.

    Toe-In is added to make cars more stable. Stock cars are usually configured to have a touch of understeer as apposed to oversteer, for obvious reasons. Positive Toe stabilizes the rear end making for understeer vs oversteer (as much as the setting can impact) So you should find STOCK cars set up to run a touch of Positive rear toe.

    Adding "Toe" is like twisting your feet inwards, the more you twist, the closer your toes become. Reducing toe is like twisting your feet away from each other.
     
    Last edited: Nov 1, 2009
  8. canieaturchikn

    canieaturchikn

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    this is what bugs the hell outta me. the game sets the rear toe default to like +20 on all cars wtf right. start at zero and tune your toe that way. but what i would actually do first is set the rear toe to zero, then make the front springs and dampers stiffer than the rear. try like 8 front springs and 5 for the rears then like 9 for the front dampers and like 6 for the rears. yes i know the engines in the back. but this is exactly what Honda did to the NSX Type R to reduce oversteer when you are hitting the brakes hard or in transition between corners. just remember that each value in is in KG's. it would be great if GT5 will let us tune for more than 10kg.
     
  9. slowman

    slowman

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    As canieaturchikn mentioned, setting the front springs and dampers to be stiffer than the rear will help mitigate the lift-off oversteer a bit.

    When the throttle is lifted, some weight shifts from the rear to the front. When the front is stiffer this effect can be minimized greatly.

    I personally stay away from toe adjustments unless the car is totally a lost cause.

    Another suggestion I have is to tune using the crappiest tires possible. This will bring out the car's worst attributes and you can tune them away or eliminate them as much as possible. Then when you go back to S-tires the car will behave that much better. :)
     
  10. SiNiST3R

    SiNiST3R (Banned)

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    The game is trying to reflect reality, the reality of things is cars come set up to understeer. Its thought to be safer then oversteering. Hence the positive toe in the rear. GT uses general default settings to certain area's for MOST cars. There are a few that are different then most. Usually the default settings reflect the truest nature of the car/set up used on the actual car. keep in mind your adjusting Stock parts, not aftermarket so your range of adjusting wont be as vast as it would be, if it was the latter.
     
  11. canieaturchikn

    canieaturchikn

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    this is true as far as real life is concerned. but the game has +20 rear toe on all cars. this is not reality, it's a game and a good one but i think PD should've tuned to true stock and left the custom tuning to the player. because PD did this i am inclined to think that they are just using GT4 physics with +20 rear toe on all cars. please say its not so.
     
  12. CaptCalvin

    CaptCalvin

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    What SiNiST3R is saying is that most cars, in real life, COME STOCK WITH +20 rear toe. Also, NOT ALL cars come stock with +20 rear toe, as the F2007 comes stock with -50 front toe and +50 rear toe.
     
  13. canieaturchikn

    canieaturchikn

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    yes i understood what he said. but +20 on real life cars is not true. take for example the acura RSX. in real life it comes with a few degrees toe out in the rear. this is not reflected in the game so you see what i mean when i said,"i think PD should've tuned to true stock and left the custom tuning to the player". and i have no idea what the default toe setting is on the F2007 because i don't have one yet but thanks for the info it is duely noted.
     
  14. SiNiST3R

    SiNiST3R (Banned)

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    I think PD went ahead of themselves and adjusted cars that needed adjusting inorder to be drivable and to take into account the limitations of the control inputs/physics in the Game. That's why the figure is relatively static. Cars come Stock with positive toe most of the time, however the degree & weather its even positive (although it usually is not just for oversteer, but for suspension load as well) varies from car to car.

    For an example of this reverse the toe settings on the NSX and take her for a spin, literally ;)
     
    Last edited: Nov 2, 2009
  15. CaptCalvin

    CaptCalvin

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    Unfortunately, it works in the complete opposite way. The same amount of weight is shifted to the front no matter what your suspension settings are. So once you get that concept down, do this experiment: take a spring and drive it into the palm of you hand without piercing it. After you done that, take a solid stick with dimensions similar to the spring and drive that into your hand with the same amount of force. Which hurts more? Now apply this newly learned knowledge in car tuning :)
     
  16. SiNiST3R

    SiNiST3R (Banned)

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    Your right, and your example is excellent.

    You can reduce the weight transfer a bit by lowering the ride height, this will lower your center of gravity and reduce the amount of weight transferred. Not by much but it does reduce the W/T & adds to lateral grip.
     
    Last edited: Nov 2, 2009
  17. canieaturchikn

    canieaturchikn

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    correct, however and i think you will agree unless you are just on here to disagree. this is the point, having stiffer front springs will keep more contact pach on the rears while braking hard and in transition between corners. if you stood against a wall holding one pillow while a brick is thrown at you then after that hold ten pillows while that brick is throw at you again with the same force...does one pillow cushion more or not?
     
  18. SiNiST3R

    SiNiST3R (Banned)

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    No matter what your suspension settings are outside of ride height they don't reduce the amount of weight transferred, but rather change the speed that its transferred. If the settings are too stiff the transfer will be too quick and the tires will be overloaded quicker. Too soft and switching directions will be lethargic as you have to wait on the suspension to load (common characteristic of old school muscle cars) So as most things its about balance. ;)
     
  19. NLxAROSA

    NLxAROSA Premium

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    Yes it will. Unfortunately, the R8 LMS is already very low, and (depending on the track) it needs a bit of raising rather than lowering.

    What you are referring to are dampers, not springs. If you are searching to adjust the behavior of the car under heavy braking/transition in corners, that's where to look, rather than the springs. You cán iron out lift off oversteer by stiffening the front dampers in some cases. It will usually also leave you with an understeering pig the rest of the time. ;)

    BTW, I have a really nice tune for the R8 LMS for the Nurb. I will post it tonight if you like.
     
  20. canieaturchikn

    canieaturchikn

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    ^agreed
     
  21. Rotary Junkie

    Rotary Junkie Premium

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    Stiffen the rear.

    Yes I'm serious. It'll reduce the dive (by way of reducing expansion of the rear), reduce forward weight transfer, and generally let the rear end keep its grip better.

    Stiffer front and rear dampers will help as well.
     
  22. canieaturchikn

    canieaturchikn

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    you're not for real are you?
     
  23. SiNiST3R

    SiNiST3R (Banned)

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    Im not sure if he is but...

    Stiffening anything will not reduce the weight transferred, its physically impossible...

    In-fact Stiffening the spring will have the opposite effect, making the weight (same amount) transfer faster, overloading the front tires that are, slowing you down, keeping you straight, or guiding you through a corner. How much do you think those tires can handle?

    That will reduce squat under acceleration ;)
     
  24. Rotary Junkie

    Rotary Junkie Premium

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    What reason would I have not to be?

    It most definitely fixes lift-off oversteer. If you overdo it the car might get a bit skatey under throttle but as always it's all about balance.

    Edit:

    @Sinister: It won't reduce the weight transferred directly, but it will indirectly reduce forward weight transfer under lift-off and braking by way of reducing rear suspension expansion.
     
  25. canieaturchikn

    canieaturchikn

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    yes we have agreed on that already. i want rotary to expalin his statement more in-depth so i can better understand his logic.
     
  26. SiNiST3R

    SiNiST3R (Banned)

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    Sore my latter comment was to him.

    Rotary: No it wont, the same amount of weight will be transferred still.

    Your mixing up whats going on. What your doing is changing the rate the weight is transferred under lift off to suit your driving style, NOT the amount of weight transferred.

    Adjust the Dampers for this YES

    Stiffening the springs however will increase the rate of transfer therefore increasing the problematic characteristic.

    Sometimes (and I'm not saying this case) the effects you think your feeling from your tuning adjustments is all in your head, sometimes your logic overwhelms your feel, Or what you think should be the outcome sometimes becomes the outcome regardless of the outcome.
     
    Last edited: Nov 2, 2009
  27. Rotary Junkie

    Rotary Junkie Premium

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    Nope. Less will.

    Nope. Because of the nature of what is being done, I am lessening the forward weight transfer under braking by way of reducing CoG migration. Less rear expansion = less upward and forward CoG migration. Which means less forward weight transfer.


    No... Stiffening the REAR springs, as I've tried to point out, lessens the forward weight transfer in the situation causing the problem.

    Edit: Jeez, stop editing, lol

    Perhaps. But I think after 2 years at this I'd think I know what I'm doing ;)
     
    Last edited: Nov 2, 2009
  28. canieaturchikn

    canieaturchikn

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    so essentially you are saying that stiffening the rear will prevent the suspension from expanding therefore not let as mouch weight transfer to the front. right? i hope you realize that the damper, not the spring controls most of the dive, squat on a car not the springs. why do you think they call them springs?
     
  29. Rotary Junkie

    Rotary Junkie Premium

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    /sigh.

    The dampers will control the rate at which the expansion/contraction happens but the springs themselves will dictate how far they can expand and still apply force.

    There's a reason drag racers use very, very soft front springs. ;)
     
  30. SiNiST3R

    SiNiST3R (Banned)

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    The same weight will be transferred you really need to learn this its a matter of PHYSICS. It doesn't matter what you think is going on, what your saying is physically impossible, your argument is about after the fact, you think AFTER the weight is in motion that the stiff springs are going to slow it down, again impossible. The stiff springs will not stop the forward weight transfer (or reduce the amount in any way) Its as simple as that.