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. HBR-Roadhog

    HBR-Roadhog

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    So what are a few of the cars where the problem is the most noticable? I would like to do some testing myself but so far have not ran across a car where the wheels seemed to be an issue. Most of the cars I have changed wheels on would have had the same size tire all around anyway but at least a few of them I think would have had wider on the rear but so far I have not saw a difference in looks or performance that I could notice
     
  2. Vagabond

    Vagabond Staff Emeritus

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    You've answered your own question. If a car has wider rears than fronts, there's the clue.
     
  3. 194GVan

    194GVan Premium

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    the problem is more noticable with mid or rear engined cars, as they sort of depend on the wider tires to keep the rear end from getting realllly loose when braking/turning/both. reduce that contact patch and the extra weight at the back of the car will really make itself known.
     
  4. CSLACR

    CSLACR

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    Actually, no. Just having wider tires on the rear doesn't tell this tale. I tried the ACR and couldn't notice it, at least not enough without a proper ghost.

    So someone looking for a good tester car can't just grab any car with bigger tires on the back.


    I would imagine an Elise would work perfectly though, yes?
     
  5. 194GVan

    194GVan Premium

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    I have a couple tuned S2000's, the rear tires are 30mm wider than the fronts on stock wheels. They are already touchy at their limit on Comfort Softs for this week's Seasonal event, The springrates I am running are computed based on the weight, distribution, and tire widths. Ill throw custom wheels on them and see if I notice a difference. If there is a difference in handling it will be immediately noticeable.

    with the elise I think its at least visually noticable with custom rims from the screenshots I have seen. suddenly, a bicycle tire! I havent got around to doing anything with a lotus myself yet.
     
  6. Vagabond

    Vagabond Staff Emeritus

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    Yes it does but obviously the effect is proportional to the car's inherent stability. Instead of imagining, why don't you just pick a high powered MR car and try that... I don't understand why you're being obtuse. We've tested this to death and the effect is now well documented, so what exactly are trying to prove? Or is there a sub-plot I'm missing?
     
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  7. HBR-Roadhog

    HBR-Roadhog

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    No I did not answer my own question, I asked for a couple of examples were the problem is most noticeable. You offered nothing in your post to that end. Why bother to post if you are not adding anything?

    So again, what are some of the cars where it is most noticeable. I would like to do some testing but do not want to have to buy 30 or 40 cars just to find one that has an issue when others apparently already found some where it is an issue
     
  8. Vagabond

    Vagabond Staff Emeritus

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    Well not to put too fine a point on it, its my thread, I'll bitch if I want to. :tup: If you've read any of, incidentally, many cars are cited with quite a severe reaction to fitting custom rims. I even mentioned one myself in post #3.
     
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  9. CSLACR

    CSLACR

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    Did I say somewhere it wasn't true?
    Or did I inform someone asking that, in fact, it is not best to just "grab any car with bigger tires on the back"?

    I'm fully aware the bug is real, I heard it first from Vagabond and Stotty, and then I tried it, and of course they were right.
    **However** - The first time I tried it, I wondered if you guys were crazy, because I "grabbed any car with wider tires on the rear", and that didn't turn out 100% accurate. (It is accurate, but it's simply too hard to tell on some cars)

    And below is why I said it. To help this guy. :)
     
  10. Vagabond

    Vagabond Staff Emeritus

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    Come on Dom, I know for a fact you're smart enough to work out that an inherently stable car is going to suffer less. So should most people be... This is just fluff. I'm not getting why.
     
  11. HBR-Roadhog

    HBR-Roadhog

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    Ok, I see you mention the F40 in post number 3 I had not saw that before. I had noticed the RGT in the OP and thought that the BTR would likely show it even more since it is a tail happy beast anyway but did not see an issue with it that stood out. I may look into the F40 and see
     
  12. jtqmopar

    jtqmopar

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    'The wheels are also uniquely styled silver five spoke 18-inch (460 mm) x 9.5-inch (240 mm) alloys wrapped in aggressive BF Goodrich G-Force KD tires.'

    It had the same tires all the way around, as with most if not all Stangs on that chassis. Foxbodys on up to '04 ran the same chassis.

    Now, the aftermarket wheels are probably programmed in at 18 x 8 or 18 x 9
     
  13. Azabear6

    Azabear6 Premium

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    I agree the more stable the car the less pronounced the effect. Same with low PP compared to higher. In all testing i've done lap times are slower and handling is more difficult. This issue imo is the single most frustrating issue with GT6. When racing your slower and whether in the garage, replay or photo mode you have a constant visual reminder. Lets hope they fix this soon.
     
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  14. jtqmopar

    jtqmopar

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    Also, going on my personal theory of the wheels being programmed in at an average width to height wheel, older muscle cars with 15" wheels factory should get an improvement. Most 15" factory wheels would be around 6.5" wide, while aftermarket steelies like Cragar and AM will be around 15 x 8"
     
  15. 2cam16

    2cam16

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    Like I said in one of my previous posts, the ELISE is affected. Trust me, I tried both stock and aftermarket wheels on it.
     
  16. raven214

    raven214

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    I read this as saying the visual difference is an indication that something is wrong, but it's also part of a larger problem (tire changes in any form - rims in GT Auto or fresh tires at the track) and that the change is happening in the data/physics regardless of the graphics. Specifically, that it may not be showing up visually after pit stops (still unconfirmed either way AFAIK) because the tires are rendered based on the car as it enters the event.

    I never meant to get in an argument over reading what another person said. @stb155 can tell you exactly what they meant. I eagerly await further testing to confirm whatever it is that's going on here.
     
  17. CSLACR

    CSLACR

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    Yes and no, apparently. :lol:
    You're viewing the ACR as stable, while I was viewing it as a 637hp rwd car on SH that "should" suffer a serious grip loss taking all that tire off the rear. (at least imo)
     
  18. cbb

    cbb

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    do you have to change the tires then view them in photo mode to notice the difference? i tried fitting custom tires to my viper gts 13 and viewed the tires from the back and didnt notice a difference
     
  19. eSZee

    eSZee

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    Tires don't change anything, wheels do.
    If you change the wheels and exit the wheel screen then come back to it, you'll see the rear tires are as skinny as the front.
     
  20. Vagabond

    Vagabond Staff Emeritus

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    In theory, maybe. Depends on the size differential between stock fronts and rears but also, tyres' load sensitivity seems abnormally high in GT6, so cars that have a higher load on the rears (like MRs with high rear biased weight distribution), hence unload more under braking or throttle lift-off, are proportionally more affected by skinnier rears.
     
  21. HBR-Roadhog

    HBR-Roadhog

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    Well since I had 2 of the BTRs I decided to do some more testing with those. I took them both out in photo mode, placed them side by side like in the OP and the one with stock wheels clearly has wider tires on the rear than the one with custom wheels.

    I tuned the one with stock wheels to the point that it was fairly stable as it is a tail happy beast to start with. I then applied the exact same settings and parts to the second car so the only difference between them is the wheels and the color.

    I ran both cars 1 time in the 20 mile Willow springs race

    Stock Rims: Best Lap= 1:25.5 Total Race=12:25 -> I did get sideways a good bit in the last corner of the 6th or 7th lap thanks to a Ford GT nudging me but held it and only lost a little time there.

    Custom Rims: Best Lap= 1:25.2 Total Race =12:24 -> a little better over all but did go off track a little on one lap.

    In both cases the car felt pretty much the same, in both cases the best lap was pretty close and in both cases I ran more than one lap in the 1:25 range, I did have one more 1:25 with the custom wheels but I think i would have in the first car also had I not been pushed sideways by the GT.

    I really could not tell much if any difference in the way the cars drove, if anything the one with custom wheels may have felt a tiny bit better but nothing definitive either way aside from the look of the tires in photo mode.

    I will try some other cars when I have time, perhaps an Elise and/or some of my super cars
     
  22. Vagabond

    Vagabond Staff Emeritus

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    What was the point of this? We already know what the effect is.
     
  23. HBR-Roadhog

    HBR-Roadhog

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    Isn't it obvious, I was posting my results. In the post #3 I think I saw you say there was a 3 second difference in lap times in your test but I am seeing less than 1 second in total race time with the custom wheels actually being the faster of the two by a small amount though possibly a meaningless small amount.

    So when you say "we already know the effect" do you mean that you already know that a RR car that is extremely tail happy is just as fast with the custom wheels as with the wider stock ones or do you mean something different?
     
  24. XPLOSV

    XPLOSV

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    Brilliant write up!!! Exactly what I was after reading after 12 pages of hysteria and pointless discussion. Please do another write up when you get the chance mate. I might try a few cars in the same method and post results.
     
  25. Vagabond

    Vagabond Staff Emeritus

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    So you didn't read the first post then? I stated the findings quite without drama and they are simple facts. The subsequent debates are beyond me... as are the ongoing attempts to prove or disprove this. We found the problem, it exists, every car with wider stock rears is affected to one degree or another. Is that not clear and simple enough?
    I still don't get what you are attempting to prove. Are you a better driver than me or @Stotty? Are you more experienced perhaps? Since your ongoing tests are inconclusive, I surmise neither. We've already proved this as fact, so what are you adding to it? :rolleyes: The effect is that fitting custom rims to a car that usually has wider rears changes all the tyres to the same width as the front tyres with a corresponding lack of grip. I'm pretty sure I put that in the OP. :indiff: Simple enough, or do you need to perform a test of your own with every car in the game, which you will drive too slowly to notice any difference?

    I started this thread to inform people of the glitch. Helpful I thought... Since then the issue seems to have been confused by numerous people who seem to think their own tests will find something different. If you're getting no result, you're doing something wrong.
     
  26. Tazz69

    Tazz69

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    Has this been fixed since the 1.03 update?????
     
  27. crowhop

    crowhop

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    I've wondered the same.
     
  28. eminem09494

    eminem09494

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    Last edited: Dec 2, 2018
  29. eSZee

    eSZee

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  30. Vagabond

    Vagabond Staff Emeritus

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    Who dug this up again...? :odd:

    But yes, definitely fixed now. Fitting custom wheels now has the effect you would expect, particularly if fitting bigger diameter rims ie lower profile tyres. Remember tyres are just an un-damped spring and part of the suspension - fitting lower profiles is like stiffening the springs and increasing the anti-roll, so there is a noticeable effect on the car's behaviour at speed.