Official alignment values thread

Discussion in 'GT4 Tuning' started by Greyout, Feb 28, 2005.

  1. Greyout

    Greyout

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    I tried the above with an S2000, and my findings disagreed with what I posted about the GTO... a negative number in the rear increased rotation quite a bit.
     
  2. porschedrifter

    porschedrifter

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    THIS IS IMPOSSIBLE!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!


    Has anyone thought of emailing polyphony digital and asking them??????

    They might be able to help.
     
  3. eforer

    eforer

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    Just to clarify the whole reaction to toe-in/out in regards to vehicle dynamics. I am a casual GT player, but an avid real (no condesention implied) car and radio controlled car racer. When getting in to chassis setup stuff, I knew that toe in increased stability and toe out decreased stablility (increased reactivity and oversteer) through experience and everyone in the community telling me so. It didn't make sense to me though, I thought the oppisite would be true based on the reasoning cango_uk posted a page previous. What I didn't understand was the importantance of mechanical weight transfer resulting from a combination of steering angle of inclination, caster and scrub radius.

    Caster and SIA have the effect of raising the outside tire in a corner and lowering the inside tire when you turn the wheels, ie the ride hieght at the outside front of the car is lower and higher at the inside front. This effectively weight jacks the car the wrong way, loading the inside front tire for inital turn in until the vectored forces of direction change cause the weight to transfer to the outside tires on the corner.

    The long and short of this is that your initial turn in (before the car transfers weight due to direction change) is largely controlled by the inside tire, not the outside. Thus, toe-out actually sets the tire that does the most initial steering (the inside) with a more radical steering angle than toe in would. As the car transfers weight to the outside wheels, the effect is neutralized as the outside tires are actually less turned in (partially due to ackerman as well). Toe out makes vehicles more sensitive to inital steering, giving them more cut and making them more reactive to direction change. Toe in does the oppisite.

    In karting and 1/12th scale rc racing where there is little suspension travel this effect is used to a ridiculous extreme with incredible caster angles used to violently setup the inside tire (usually toe'd out a bit) to cut for a lot of inital steering.

    I still have no idea what + or - toe means in gt though!
     
  4. Duke

    Duke Staff Emeritus

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    Hey, welcome aboard GTPlanet, eforer. Always good to see new faces with real understanding of the physics and dynamics and engineering. Feel free to look at some of the other threads around!
     
  5. eforer

    eforer

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    thank you, its apreciated. I reccomend that all GT enthusiasts take a look at the RC hobby, it shares a lot of compelling connections with simulated racing.
     
  6. dellerbs

    dellerbs

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    Toe out, away from the vehicle, is positive.
    Toe in, toward the vehicle, is negative.

    Machines used at garages to align cars measure in this way, at least. I'm assuming it's the same in GT4.
     
  7. fraggy

    fraggy

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    Im an old skool gt player having played gt 1,2,3 as they were released and love this driving game more than any other,it eclipses them completly in playability, BUT!...... and it really does my ed in! ..........WHY ARE THE SET UP MENUS IN GT4 CRAP? They improve on graphics and the whole aspect of the car physics and then go and make it increasingly difficult to work out these over complicated set up screens (which helps us use these advanced car physics to their full) with very little visual representation of what your actually doing to your car when changing settings, for example - the confusion of which way the wheel moves when we apply a positive or negative value, for all the posts in this thread no one can come up with a 100% concete answer! and that shows how user unfreindly the menu system is ...I say let the designers listen to people who buy and play gt, people who use the settings (not people who just play arcade mode, which is a waste of disc space....in my opinion only of course!) :idea:

    p.s as far as I see....... toe in + positive = / \ (front)

    .............................toe out - negative = \ / (rear)

    this is looking down on car from above use these setting for oversteer and the opposite for under steer. imagine looking down at your feet.. if you wanted to to put your toes in you would do this..../ \ and toe out would be..... \ / :tup:
     
  8. Ske

    Ske Premium

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    You find me the email address then.

    I was back and forth with SCEA (the only related company I could find a contact form for), and in 18 replies they never even WROTE a reply. It was all pregenerated and not remotely related to my question.

    If you ask me, PD is a bunch of aliens locked up in a basement, and SCEx don't want you to find out ;)

    If you manage to contact them however, please let me know how......
     
  9. Kamukix

    Kamukix

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    1
    Instead of guessing I decided that since there are replays in the game (and the garage viewing of the cars)...just look at the way the wheels is positioned after each setting. That will show you which is which :).

    K-san

    P.S.
    At the moment I can't think off the top of my head which is which though...how's that for being useful.
     
  10. jamaican

    jamaican

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    332
    i found this site via google... while i was reading it, it reminded me of this thread

    http://www.tirerack.com/tires/tiretech/techpage.jsp?techid=4

    for anybody who's too lazy to click on it, here:
    camber
    [​IMG]
    caster
    [​IMG]
    toe
    [​IMG]
    "most front-wheel drive vehicles use some negative toe-out"
    so i guess negative toe = toe out
     
  11. sucahyo

    sucahyo

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    2,171
    Let's hope someone can test toe + is toe in or out in GT4, maybe with the help of game shark or something similar to get 6.35/-6.40 toe or something so we can see it clearly, in GT2 + is toe in
     
  12. Scaff

    Scaff Staff Emeritus

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    OK I have been playing around with GT4 and Toe setting and think I may have something of interest.

    I used a Nissan/Datsun 240z in Phototravel with a range of front toe settings and then had a look at the detail in photoshop.

    The detail is quite nasty on they as I had to use levels to get light into a normaly dark area but take a look.

    First just to ensure that settings do show in phototravel this is the car with a camber setting of 12 at the front.

    [​IMG]


    Now I reset the camber to zero and set front toe to zero and in phototravel ensured that the car was at a 90 degree angle to the camera by useing the guide line box you get when rotating the car.

    0 Front Toe

    [​IMG]

    The line is a reference tool to aid in comparison


    -4 Front Toe

    [​IMG]


    +4 Front Toe

    [​IMG]


    Result?

    Now the final shots take a bit of looking at, as the toe range in GT4 does appear to be very limited in its effect. However the -4 front toe value does appear to show more of the actual wheel cover, while the 0 value appears flat to the camera and the +4 value appears to show less of the wheel cover.

    Is this conclusive? Well I am quite happy with the angle I have used and that it has been reproduced with a good degree of consistency over the three shots. The results do seem to support the Official guide statement that a - (minus) value is Toe-in and a + (Positive) value is Toe-out.

    I would strong recomend downloading the three shots to your harddrive as it allows you view them side by side a lot easier and have a closer look.

    As always any comments, feedback, etc.

    Regards

    Scaff
     
  13. identti

    identti

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    667
    I knew the camber showed but hadn't considered the toe. You proved that GT4 does go into that much detail.
     
  14. sucahyo

    sucahyo

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    2,171
    Sorry, can you make another picture with cars that have extruded wheel? maybe catterham or Formula 1 car?

    [​IMG]
    If you look at the tire the image show that -4 is toe out, the front of the front tire is goes out farther than the +4 value.
    To make sure the picture is correct, I confirm that the -4 picture have more car body over the tire (fender?) showing.


    I think we better use more extreme toe value to be conclusive

    BTW, what is the normal maximum value for toe in GT4 ? normal GT2 is -0.20º / +0.20º, using hybrid the maximum is -6.40º / +6.35º.
     
  15. Scaff

    Scaff Staff Emeritus

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    I've tried it with the Caterham and to be honest thats even harder to get lined up straight for each shot, and again the limited range of the toe values make it hard to see.


    I'm quite happy to admit that the pics are not perfect, but I'm yet to see one that are closer for GT4. It is however why I said that it 'appears' to show. The difference between the -4 and 0 shots is small, and its from this that I have said it appears to show -4 being toe in.


    It would be nice to use higher values, 4 is the highest and lowest values in the range (four what I have no idea), as of yet I am not aware of any hybrid software for GT4 so thats all I have to work with for now.

    As with my last post I'm only happy to say that it seems to support the official guide. combined with my own testing.

    Also a lot of people appear to have missed this

    Now while this is from the Japanese version, it is another piece that matches the official guide, and may be supported by my pictures.

    Regards

    Scaff
     
  16. sucahyo

    sucahyo

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    2,171
    I still don't understand. I though that in the slightly bigger -4 toe picture you got the photo angle a little bit to the outside. So it make the wheel cover and the rear car body shows more. But even with the different shot angle, we can still measure the tire angle differences with the line, isn't it?
    What you say about the result is -4 value is toe in (turning inside more) makes me confuse. On that picture (the one you post) the -4 toe tire is closer to the line, isn't this suppose to means the wheel turning outside more?

    If 4 is max value, then anyone who has gameshark should be able to test the -127 toe. This is assuming that the toe still stored in 1 byte.

    0 toe in GT2 stored as 128, 0 in GT4
    -0.20 = 124 = -4
    +0.20 = 132 = +4
    -6.35 = 1 = -127
    +6.30 = 254 = +126
     
  17. Scaff

    Scaff Staff Emeritus

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    I think that the range of toe angles make the use of pictures very difficult, because unless the shots are all from exactly the same angle (and I took a lot of pictures to get to the point above) the variation is so small that its just not possiable to be 100% sure.

    Until (and to the best of my knowledge its not yet been done) a code allows us to put the extreme values in GT4, it will be very hard to visualy prove.

    However for GT4 (not GT2) all the evidence does point to Toe-in being negative values, from the Japanese versions tuning screen, the official manual and while not authorative my own testing.

    Toe out at the front should allow the car more grip on initial turn in (as the nearest front tyre to the corner does most of the work here) but less response as the weight transfers to the outside front tyre) during the actual turn.

    Toe out at the rear should make the back end more prone to lift-off oversteer and/or in RWD cars power oversteer. From my own tuning I am happy to say that in my experience setting Toe to positive values does just this.

    However with all things tuning it should always be carried out to match the drivers style.

    Regards

    Scaff


    Regards

    Scaff
     
  18. sucahyo

    sucahyo

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    2,171
    I see,
    About the rear toe, I experience what you describe as toe out rear using 0.00/-3.00 toe. Using 0.00/+3.00 make the car slide more but still controllable (and make me smile when the car can slide continuously on 180º corner).
     
  19. Scaff

    Scaff Staff Emeritus

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    Quite possiable if the car is already tuned or prone to oversteer then (and if for the moment we assume toe-out is + and toe-in is - and that this is a rear wheel drive car), setting toe-in at the rear will reduce the lift-off and power oversteer, but may not elliminate it. However setting toe-out at the rear will increase the lift-off and power oversteer.

    Toe setting are quite subtle (just look at the normal range you have in degrees, we are talking about very small changes to the wheel alignment) and as such will rarely eliminate handling characteristics completely.


    Front toe is also a strange one, for example setting toe-out will increase grip on turn in (as the front nearside tyre does most of this work and with toe-out is already pointing towards the corner) but reduce cornering grip once the weight transfers to the front offside tyre (as this is pointing slightly away from the corner compared to a zero toe setting).

    Toe-in at the front has the opposite effect, reducing initial turn-in grip but increaseing cornering grip.

    Personally I use front toe to match turn-in to my driving style as corner grip can be tuned through so many other factors (camber, spring rates, dampers, etc).

    Hope the above makes sense and helps.

    Regards

    Scaff
     
  20. sucahyo

    sucahyo

    Messages:
    2,171
    From GT2 experiment, both (+/-) 3.00 rear toe (should be equal to +/- 60 in GT4) make the car oversteer. It just behave in different way. + will make the rear slide, - will make the rear turn to the opposite direction of the steering (its like helping it turn). Using + toe should make the car drift happy (including FF). Using - should make the car turn happy. I feel both make the car feels more oversteer on atleast 5 car I tried (FF, 4WD, MR and FR) using non hybrid tuning.
    What is your experience in rear toe tuning?
     
  21. Scaff

    Scaff Staff Emeritus

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    I have been thinking about the use of these very extreme ssettings, and they may actual be causing part of the problem, for two possiable (or even both) reasons.

    The first is that with actual real world toe settings, the values are always very small, to small for most to even be seen by eye. For example almost every production car on the market is set-up with a small amount of front toe-in. As it aids the cars stability at speed and push the car into understeer if you exceed the grip on turn-in, both a 'safety' net for the average driver.

    However using a toe angle as high as the ones mention may well be so extreme that the rear has almost no grip to start with; assuming that front toe is normal, this would result in oversteer as the rear is always going to lose grip first.

    The second is that the values used are so high (and outside the range on the GT2 set-up screen) that they are simply not catered for by the GT2 physics engine. The programmers may have just not anticipated anyone would use them.

    Just a couple of thoughts.

    Regards

    Scaff
     
  22. sucahyo

    sucahyo

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    2,171
    I agree with the first one, in my side by side test, even when using normal maximum toe (+/- 4 in GT4, 0.20 in GT2) the tire that using toe will have less traction on acceleration but more traction in decceleration (tested using +0.20, I think I will test this again using different toe combination). So, using unneutral toe only on rear tire will make the car oversteer, because it will make the rear tire have less traction.
    About the second one, I never see any limit in my test. It seems the physics engine will process any value. Anything that make divide by zero error will result in game crash (this is the reason I use 1 as minimum, 254 as maximum when hybriding). Although using extreme value can give anomaly, but the effect it self seems proportional, extreme value has exagerated effect compare to normal value.
    [​IMG][​IMG][​IMG]

    The thing that I like when using + rear toe value on car that are very easy to spin is it will make the car more controllable (driftable turning).
    [​IMG][​IMG][​IMG]
    [​IMG][​IMG][​IMG]


    And, doing drift on long corner reminds me,
    I think the initial turn-in will happens only in a very short time, maybe in hundred miliseconds. So this will make the outer tire have the most effect if we do a long cornering, and the effect that we feel during cornering will be the outer tire allignment.
    So, if in GT4 using +4 front toe value will give you more understeer during long corner then + is toe out. And if using +4 front toe value will give you more oversteer during long corner then + is toe in.
    Which one do you feel?
     
  23. jamaican

    jamaican

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    332
    and i thought graphics were soo good back then :crazy:
     
  24. Scaff

    Scaff Staff Emeritus

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    I must admit the use of high vales causing the physics engine problems was not about it crashing, just not being able to 'realistically' account for the extreme values, but I have never tested values this high in GT2. From what you have said the engine does appear to handle it, because beyond a certain point toe in or out causes a loss of traction and oversteer.




    You are quite right that the initial turn in will only last a very short period of time, and that during sustained cornering the outer tyre alignment will be more significant.

    I still use front toe to tune for initial turn in, as it is one of the few things we can do to manage turn-in. Plenty of other set-up areas allow the tuning of understeer.

    In GT4 I am now 100% convinced that + values are toe-out and - values are toe-in. I played around with various setting on a mixture of corners when tuning the Caterham Fireblade for BESTuners. Positive values definatly improved initial turn-in and reduced the steering input once the weight had transfered. On the Fireblade this was easy to tune out through spring and camber settings.

    Regards

    Scaff
     
  25. sucahyo

    sucahyo

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    2,171
    Ok, + is toe out in GT4 then.
    About toe and tire traction, if we assume using toe will reduce traction then:
    • using rear toe out will make the car more turning oversteer
    • using rear toe in will make the car more rear sliding oversteer
    • using front toe out will make the car more sharp understeer
    • using front toe in will make the car more dull understeer

    Using extreme value, using front toe will create understeer and using rear toe will create oversteer. I don't know if +/- 4 in GT4 is big enough to create loss of tire traction.
     
  26. Boundary Layer

    Boundary Layer Premium

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    I confirmed these results for myself a few months back with my DFP.
    I got tired of trying to read through all the differnt ideas in this thread, and I generally dislike the notion of applying knowledge of the real world to GT4 as so many people posting here try to do. So I devised a simple test to allow the game to tell me which is which.

    Take a car - preferably a quick one - to any course with a long straight. Adjust your front toe one way or the other, then as you come up on the straight aim it down the center of the road and let your hands free of the DFP - permit the car to find it's own way down the straight.

    You will most certainly notice that as you set the front toe more positive you get a greater amount of wandering down the straight (just watch the movement of the DFP). This, for me, was all the proof I needed to conclude that positive toe is toe out.

    I've since used toe in a few drifting setups that I have created and I have not experienced anything to disprove this.
     
  27. sucahyo

    sucahyo

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    2,171
    It seems that even in real life there is book that use + as toe in:
    [​IMG][​IMG][​IMG]

    maybe PD use this book as reference when making GT2
     
  28. Scaff

    Scaff Staff Emeritus

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    This has been covered before, different manufacturers use different values to accomodate toe in or toe out. A large number of Asian manufacturers use + values as toe-in, most European and American manufacturers use - as toe-in.

    The vast majority of wheel alignment equipment manufacturers use neither, simply stating that a wheel is toe'd in or out by x degree's.

    Real world references to toe values are of not relivant, GT4 values are - = toe in and + = toe out.

    Regards

    Scaff
     
  29. sucahyo

    sucahyo

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    2,171
    ah, yes...
     
  30. sucahyo

    sucahyo

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    2,171
    So, I was right thinking that 0 toe will be stored as 128 too in GT4, it even have almost the same memory storage layout as GT2 for suspension (except 2 byte for ride height, etc).
    This is GT4 with in memory 0 toe, maybe equal to on display -127 toe, don't know, can't buy fully cust suspension to check it with only 10,000 credit at start.
    [​IMG][​IMG][​IMG]
    [​IMG][​IMG]