Custom wheels give all 4 tyres the same width.... changes grip and balance

Discussion in 'Gran Turismo 6' started by Vagabond, Dec 18, 2013.

  1. Awong124

    Awong124

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    You can't as far as I know.
     
  2. stb155

    stb155

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    I'am certain now that the "custom wheel bug" and "pit stop bug" are the same thing basically.

    If i use custom wheels on the McLaren i have the same handling and tyre wear as after the pitstop with standard rims from the beginning and no change after the pit stop.

    With standard wheels i do 5/3 to avoid the issue of running out of tires, if i try that with custom wheels i run out of tires in 5th (not completley but it gets very sideways)

    I also verified it with the 2013 Viper, same thing but the difference is not as pronounced as with the MP4-12C as the Viper has slight oversteer from the start. But it gets more after pit stop and i can fell the loss of traction in 3rd gear.
     
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  3. DCP

    DCP

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    I was wondering about this, thanks for the thread OP.
    I also used an Aventador for one of the Single player events, and all I did was add Racing hard tyres, I think it was on Siverstone full in S events.

    The aventador was undrivable, oversteering even at low speed corners. How am I supposed to fix this issue.
    Do I buy custom rims and increase the size?
     
  4. Flaren89

    Flaren89

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    I think ppl have recently destroyed this thread... Start talking about the loss of grip after the pit stop which isn't the start thesis (there is another thread for this) and point that they changed stock tires (not rims, which is the object of this thread) if they can't drive some cars, when some pages ago we already told that only rims change tires width, not the tyre compound itself... Bah...
     
  5. stb155

    stb155

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    Could you at least try the races with the cars i said before you call me just to stupid to drive ?

    Or proof in photo mode that there are no changes in tire width after pit stop ?

    (And even if it not shows in photo mode it is possible that it is the same bug in the physic model)

    And i never said that the compound changes, it is just the same as with custom wheels.
    Handling changes on cars with wider rear tires.
    I also tried with Evo X and Toyota 86 and on those everything stays the same after pitstop.
     
  6. raven214

    raven214

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    Initially I thought the 2 issues were separate - and they may still be - but someone posted that they sounded like they could be connected, and that the pit stop bug affected offline, which was news to me, so I linked the thread I had been following about pit stops. My intent is to bring light to these issues so we can get to the bottom of them and help get PD's attention to fix them.

    I don't know if the two issues are related, but why not discuss to see if they are? Maybe pit stops are putting front wheel (width) tires on the rears. Maybe it's something else altogether. I hardly see how discussing the similarities of these bugs/conditions is ruining this thread. At least you can avoid the custom rims bug by going stock - pit stops cannot be avoided in any racing of significant length.
     
  7. stb155

    stb155

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    Thanks, i really don't want to "hijack" this thread.

    It honestly think those 2 issues might be linked in a different way than most of you think.

    You think there is a "custom tire bug" and a "pit stop bug"

    I think there is a "custom wheels give all 4 tires the same width optically" and a "every wheelchange no matter if in pit or tuning shop sets all 4 tires the same width in physics model" bug.

    Why i think that ?

    Because after pitstop on custom wheels nothing changes.
    Also after a pitstop with cars that have same front/rear tire width nothing changes.
    But if you have a pitstop in a car with wider rear tires on stock wheels you have 100% the same symptoms you get with custom wheels.

    But it seems there is no difference in tire width if you look at the car in photo mode.
    (PLEASE can someone confirm that ?)

    So i believe the tire width shown has no influence on the grip level.
    We only see the difference in photo mode from custom wheels because they get displayed/rendered separately from the standards.
    And if PD would only fix the "custom rims give all tires same width bug" we would still have the same issues with changed handling after custom rims install or pitstop.

    I tested this about 7h now in the "S" races and found nothing that indicates otherwise.
    I am pretty sure you don't just get a different compound at the pitstop, this feels completely different.
    (Tested it, SH/SM or SH/CS, feels and sound total different, gives different tire wear)
    But if i put custom rims on any car it always feels like the same car with stock rims after 1st pitstop.

    Edit:
    Tested it with Enzo, Viper, F1(road), MP4-12C, F40, V16T on Willow Springs 20min.
    And Evo X and Gt 86 to verify that there are no changes on cars with same tire width.
    (Both tuned a bit to get ~equal front/rear wear)

    On the MP4-12C i feel it the most because it is so clean/predictable to drive, it makes a clear change form understeer to oversteer in fast bends.
    I feel it in the others to but not so much because they all can oversteer from the start with lift off or weightshift. But on all i feel that they loose rear grip and also always do my best lap in 2nd and not 5th. Rear tire wear also increases on all, but again most on the MP4-12C
     
    Last edited: Jan 6, 2014
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  8. DCP

    DCP

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    Hmm, I tried the Aventador again, both with rim change and stock rims, using racing softs on S event, 10 laps Silverstone. both times car is undrivable. Please try and let me know. I would think it's a bug that needs fixing.
    Avantador is bone stock in all aspects.
     
  9. CSLACR

    CSLACR

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    How have you determined that?


    Car drives great imo, just a loose-on-entry car.
     
  10. GordonS

    GordonS

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    Sorry. Never mind.
     
  11. Z1-AV69

    Z1-AV69

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    I did the Willow Springs S-class race several times with a McLaren MP4-12C (tuned, with a custom setup and sports soft tyres on stock rims) I never noticed a difference on the second stint. I got like 15.000km already on that type, so I know it well. It took me like 2 corners to be sure about the aftermarket wheel bug, it was so obvious once I got the feel for GT6.
     
  12. Vagabond

    Vagabond Staff Emeritus

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    It must be noted that if a car doesn't seems too tail happy with stock rims, its driving style that needs adjusting; this is nothing to do with a tyre glitch.

    I'm doing some tests with pit-stops but no conclusion thus far.
     
  13. DCP

    DCP

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    Thanks for effort, but thats not the way it drove in GT5 surely. That loose entry was never a problem. Infact she still drives great with Sports hard and sports soft.
     
  14. eSZee

    eSZee

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    :rolleyes:
    Yes, tire width has effect on grip. This whole thread is about that.
    I suggest reading from the top.
     
  15. stb155

    stb155

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    One more thing i just noticed it that brake bias has some relation to that thing on the MP4-12C.
    If i use standard 5/5 i feel less difference before/after stop and have less problems with rear tires after the stop.
    (Edit: i use 5/8 usually)


    How do you know ?
    Just because of the "custom rim bug+photomode proof" or is there another source ?


    I'am not 100% sure about this, with street cars the effect is a lot less than with race cars in the Apricot&Silverstone races but on race cars i cant test with custom rims.
    (Or lets say the Willows race is tho short)
     
  16. eSZee

    eSZee

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    Because I can tell whether a car handles differently or not.

    If nothing changes on a car other than rims and the difference in behavior is almost night and day, I think it's safe to assume there is a grip issue, unless unknown to me, I was injected with a liter of alcohol in the 20 seconds it took me to change wheels. That could also be a reason.
     
  17. raven214

    raven214

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    He's talking about visually. I suggest reading his post again.
     
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  18. Z1-AV69

    Z1-AV69

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    Interesting. I use 4/5 (ABS 1) with this car. In GT5 I always thought brake balance with ABS changes more than it should. I came to avoid anything above 5 because I thought it would generally lose grip. But I never did real solid tests.

    I tested it with my tuned 12C at Mount Panorama at the light lefthanders on top of the mountain. With stock rims (and that setup) I run that part at almost constant speed and no need for corrections. Despite the steps down during the corners the car stayed it's course to make one big smooth turn. With stock rims the rear tyres stayed rather cold, no yellow at all. Same car with custom rims (same speed) is a totally different experience. The rear will break loose on "landing" after every step down (only very little throttle to stabilize, no accel) and the temperature of the outer rear tyre turns orange after the first step down and stays orange until the end of the straight all the way down the hill. From my experience the effect of the smaller rears is more noticeable if you test for lateral loads on the rears, which might be a little difficult. But on heavy accel with higher power it's probably noticeable by higher temperature too, like someone stated from Monza before.
     
    Last edited: Jan 6, 2014
  19. Matt368

    Matt368

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    Is the visual difference apparent right away from the preview shot of the car in GT Auto? If you were to select standard then custom one after the other can you see the width difference?

    I changed wheels on my S2000 last night after hearing about this bug but couldn't see a difference in GT auto.
     
  20. Youngun

    Youngun

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    Has anyone done a before and after pitstop photomode pic for both custom and stock rims yet? To see it after both pitstops the tires are fronts on rear?

    Think we can all agree of the lost width equals lost friction meaning lost traction equalling lost time. But if the pitstop is linked, wheel changes in general could be the cause, not just custom wheels
     
  21. Flaren89

    Flaren89

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    For the wheel change, do you remember my double picture post last page? In that one, there were both rims and tires compund differences and i posted because of the rims... Now i post the comparison for ONLY the wheel change (left Hard Racing, right Hard Sport):

    [​IMG]

    As you can see, other than Toe and Camber in the GT3-like tuned, there aren't any differences, so the "tires-compunds-change-tires-width" argument is invalid...

    Less one, let's destroy the other wrong thesis:

    For the width change on the pit-stop, i have some thoughts...
    First, ppl point out that after the pit stop, laptimes are worst by 2-3 seconds, and in fact that's true... But, i think not only for the tires... Instead, i don't think tires are the cause...
    I think instead that the game "tries" to simulate an "exhausting" on the engine, and at the same time a "little damage" on chassis and suspensions when you go on the pit or after x miles/kms... Even if this don't appear later in the GT Auto maintenance...
    Proves? The engine prove i have it's that at the Ascari endurance with my 643PP GT-R before the pit stop i have to put the 6th gear 50m before the final mini-turn in the long non-straight, meanwhile after the pit i change to the 6th only 10m before, so the engine push to the same speed 40m worst than before...
    And if this happens on the engine, it can be a "little failure / damage" on the chassis too, that leads to a less stability on the corners...
    Less powerfull engine + less stability for the chassis = higher laptimes...

    Both arguments have been killed, so the only bug it can appear it's the rims one that has been proven from the first page...

    For the pit-stop one I would like to also post it on the right thread, but if I already told here, there's no true need...
     
  22. HBR-Roadhog

    HBR-Roadhog

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    I was playing around with the RUF BTR which I would think would have wider tires on the back due to its tail happy nature. I changed the wheels and there was no noticeable visual difference in the tire width. I drove it in the 20 mile Willow event and then drove another one with the same setup but with stock wheels. Can't say I noticed a difference. I did do slightly better with the one with stock wheels but I think that was just due to having driven the first one 8 laps before getting in the second one. Both felt and looked about the same aside from one having better looking wheels on it.

    I also did not see slower lap times after pitting, all clean laps were about the same before and after pitting in both cars. I have not yet tried the test online to see if it is different there.
     
  23. Youngun

    Youngun

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    You would be screwed in an endurance event then as 30 pitstops later, you lap times could be down minutes.
     
  24. Gedi69

    Gedi69 Premium

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    ive found that a bmw m3 07 is faster with custom wheels on.
     
  25. Flaren89

    Flaren89

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    Well, tires and fuel have a increased consumption, so theorically you can have a increased consumption on engine and chassis, too... And remember that in old GTs you get a "oil exhaust" issue on long ones, so maybe they want to try simulate that also for short endurance we have atm...
     
  26. eSZee

    eSZee

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    what? Am I misunderstanding something? He's saying there is a visual difference but not a mechanical one, which is not the case.

     
  27. andryush

    andryush

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    I determined this after reading this thread and testing cars for myself.

    Handling actually changes when you change wheels ---> It's because when you change wheels, game reduces rear tyre width ---> this means that physics is now calculated basing on new, lesser tyre width <--- physics engine takes this factor into account.
     
  28. stb155

    stb155

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    Then maybe its that, i notice something is different after a stop even when i do it in the first lap.
    It feels similar to using using custom rims, but i can go faster on those as with standard after a pitstop it seems.

    I tried running a tank empty (6laps) on standard rims, restart and stop 1st lap and do 6 laps again, next put custom rims on and did 6 laps again without stop.
    1 felt normal and gives best tire wear, 2nd feels different and i am slower or use more tires (or both), 3rd feels similar to 2nd but is faster and also has increased tire wear to 1.

    If i do the same in Apricot Hill 20min. with Race F1 (Stealth) it is much more obvious, if i do 10 laps front right tire is lowest (~30%) rear is fine (little under 50%).
    If i turn around after start, go in pits for tires/fuel and do 10 laps car feels totally different.
    Rear tires wear same or even faster as front, hard to finish 10 laps without to slowdown a lot.
    Only thing i did not try on the race car is a rigidity restore (but why would that have effect only after pit stop)

    Bought a new MP4-12C for the tests today as my old one has 1300km, first i thought that makes a difference but it turned out it was brake bias who made a difference.

    But i'am no longer sure about anything :sick:
     
  29. Vagabond

    Vagabond Staff Emeritus

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    Is it just a simple case of adjusting to new cold tyres after changing from worn warm tyres? First lap on cold tyres is always tricky, and if you burn them up on that lap, you might not get them back. Just a thought....
     
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  30. stb155

    stb155

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    This would be only in 1st lap then, but the car always feels different after stop.
    And tire wear at rear is almost double as strong (depending on setup) while at front it stays the same.
    (With the race cars, not sure with the MP4, its tank is to small to test it to the end)

    Edit:
    And no, i never burn the tires on the racecar, on the streetcar maybe for a short time but onle when they get worn, not at the start.