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Is There a Definitive Answer? 20" Sport Wheel Includes Rear Upper Fore Links / Control Arms

Discussion in 'Model 3' started by tiltmode43, Sep 20, 2018.

  1. tiltmode43

    tiltmode43 Member

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    As you may already know, the 20" Sport wheel option seen here -> Model 3 20" Sport Wheel and Tire Package includes the following:
    • 4 x 20X8.5J Sport wheels
    • 4 x 235/35/20 – Michelin Pilot Sport 4S tires
    • 4 x tire pressure sensors
    • 4 x Tesla logo Sport wheel center caps
    • 2 x rear upper fore links
    I, and seemingly many others out there, would love to know why. There are LOADS of theories as to why the 20" Sport Wheel option includes different UCA's. Here are a handful of ideas:

    To slightly lower the car - I can't imagine this is the reasoning, I can't imagine they would advertise and sell a 20" wheel package that lowers just the rear of the vehicle intentionally, and makes no mention of it in the text.

    Higher load rating - I don't think this can be the reasoning. The loads achieved by super sticky 18/19" tires would likely outweigh any marginal increase in weight from the 20" wheel & tire package.

    To create proper clearance for the wheel/tire - The outer diameter of the 20" setup is virtually the same, and the width/offset are fairly conservative (20x8.5 +35 or +40 IIRC). So, I can't see it as related to wheel/tire-fender clearance. Furthermore, there are tons of TM3 owners with 20" aftermarket wheels.

    To add some negative camber, to increase handling performance - There is no OE camber adjustment, perhaps these slightly modified fore links add just a small amount of negative camber to optimize performance of the "Sport" wheel/tire combo? Perhaps the OE camber spec in the rear of the TM3 was not "ideal" for track times, but rather normal/efficient driving, so Tesla included this slight change to the "Sport Wheel" package, as well as the Performance Option on Performance AWD, as those who purchase either of these would be those looking to get maximum performance? Has anyone checked the camber before / after installing the 20" Sport upper fore links? I would be pleasantly surprised if this was the reasoning, I'm not sure any OEM would mandate an extra part purely for maximum performance in ideal environments, but who knows?

    I'm not sure the internet has the answer as I've spent quite a bit of time sifting the web for details, but came up short. I'm hoping I missed something and that someone here knows for sure the difference. If not, let's see if we can find an answer! Theories are welcome, but please don't post anything as the "definitive answer", unless you know it absolutely to be the case.

    Oh, and is anyone in the process of upgrading their non-20" wheels to the Sport wheels? Maybe we can see some pics of the new RUCAs before installation Vs old RUCAs after install? Wishful thinking :D
     
  2. yearofthedragon

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    Side impact test not passed when using original forearm links. Forearm links were likely bending with 20" wheels installed upon impact.

    Tesla has likely already replaced the rear forearm link in current production model 3's.
     
  3. eSpiritIV

    eSpiritIV Member

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    All you have to know is that the Model 3 has some of the best suspension in the industry.
    if you want adjustable, you can buy aftermarket ones from Mountainpassperformance
     
    • Disagree x 1
  4. kbecks13

    kbecks13 Active Member

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    Source?
     
  5. remlemasi

    remlemasi Member

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    Do we any more info on this? What exactly do the updated rear upper fore links do? Any geometry changes? What are the repercussions of installing Tesla 20" Sport wheels or aftermarket 20" wheels without installing the new links?

    @MountainPass do you know?
     
  6. MountainPass

    MountainPass Vendor

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    It is unclear to us which arms they are referring to, if anyone has a photo circling these specific links, we can give you an answer!
     
  7. Knightshade

    Knightshade Active Member

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    Description says "rear upper fore links"

    Which appears to be item 3 in this diagram from Tesla

    https://epc.teslamotors.com/#/systemGroups/47402
     
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    • Love x 1
  8. MountainPass

    MountainPass Vendor

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    Thanks Knightshade, after viewing this diagram, I personally agree with the crash-test hypothesis, if they wanted to make geometry/alignment changes they would have replaced the camber or toe links.
     
    • Helpful x 1
  9. Drax

    Drax Member

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  10. Knightshade

    Knightshade Active Member

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    I think maybe a week?

    I posted a thread about it showing no difference in the drive units for the P versus RWD/AWD, as well as some of the differences in shocks/springs/swaybars a few days ago.
     
    • Love x 2
  11. remlemasi

    remlemasi Member

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    Thanks for the input, although it's interesting that the diagram doesn't list both PNs (old and current). That supports the second part of the @yearofthedragon hypothesis, that these changes were made to all current production cars, with or without the 20" Sport wheels.

    Does anyone have anecdotal evidence that, when purchasing the 20" Sport wheels post-delivery, Tesla is only upgrading the control arms on older cars that didn't already have them? Do newer cars getting the upgrade not need the new control arms?
     
    • Like x 1
  12. sissupr

    sissupr Member

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    Curious. Bumping this thread. Is there a definitive answer here? I’m asking also because I’m selling my 20” performance wheels to a non-performance (LR, RWD) and the buyer is asking if he needs to upgrade his links since I’m not including mine in the sale.

    I’m sure others are also curious as more Model 3 Performance owners seem to post there wheels for sale often on this forum. It would be good to close this discussion out... Tx!
     
  13. rdlink

    rdlink Member

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    I thought the 20" performance wheels were incompatible with non-performance models, and vice-versa?
     
  14. sissupr

    sissupr Member

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    Sry, correction... the buyer has a Model 3 LR AWD.
     
  15. FlyNavy01

    FlyNavy01 Member

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    I sold my 20" wheels to a LR AWD owner and they worked fine. Not sure why Tesla's website says many of the wheel/tire packages won't fit certain models, because I've found it's often incorrect.
     
  16. SJC3

    SJC3 Member

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    Just because something bolts on doesn’t mean it’s ideal for performance or even crash worthiness which seems to be a reasonable hypothesis here.
     
    • Like x 1
  17. FlyNavy01

    FlyNavy01 Member

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    Literally the only difference is an extra 3lbs from the 19" version, I think they'll be okay.
     
  18. Knightshade

    Knightshade Active Member

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    If that's the only difference why does Tesla go through the trouble and expense of making different rear upper control arms and swapping them onto the non-P car when you buy the 20s for it?
     
  19. Drax

    Drax Member

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    @Knightshade IIRC, only early VIN’s actually need the suspension change. I don’t remember the specific range, but it should be in the parts catalog.
     
  20. Knightshade

    Knightshade Active Member

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    Again- there were two suspension changes on the RWD LR models.

    One is for cars built after Dec 17, 2017. Both front and rear spring/shock assemblies changed.

    The second is cars built after June 19, 2018. Only the fronts were changed.
     

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