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Suspension settings and camber - Saving rubber

Discussion in 'Model S: Driving Dynamics' started by slipdrive, May 18, 2014.

  1. slipdrive

    slipdrive Member

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    A lot has been said, with good reason, about excessive rear inside tire wear. Boiling it down all together would help to to understand. I just lost probably 8K of use on the original Goodyears, when inside cord appeared with only 7K on the tires, (and only half of that on the rear). In hindsight, wear may have been accelerated by setting the "low" suspension to 60mph when 5.9 arrived, so I have reset to 75mph. I am wondering if it is known: How exactly does camber change with the suspension heights. ? And if it saves tires, why can't we adjust the suspension to stay in "high" around town under say 45mph if desired? Does it affect geometry and handling significantly? I have an appointment at the SC next week to take "some" the negative camber out. I've read the great advice by @lolachampcar and others about optimized alignment and camber, will request those optimized settings and hope this will help. Even at the lower cost of the Goodyears versus more premium tires, the cost of rubber approaches DOUBLE the cost of kwh/mi driven, if you lose half life on the tires...., Personally, I will gladly give up some aerodynamics, and take a bit more rolling resistance in the tires, to get to 15-20K per set. Thanks
     
  2. JohnQ

    JohnQ Active Member

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    Something more must be wrong with your alignment if you got only 7K out of the Goodyears. I have 10k on mine (and 8k on my winters) and the treads look great. Most of that was with auto-lowering enabled. Get the SC to do a full alignment.
     
  3. zwede

    zwede 2013 P85+

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    I measured a gain of 0.5-0.6 dgr between normal and low suspension settings. If you have -2.0 dgr camber on normal, you'll have -2.5 dgr on low. The MS rear camber is truly horrendous. I hope someone offers an aftermarket upper control arm with adjustable length soon. It would solve the issue.
     
  4. slipdrive

    slipdrive Member

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    Yeah, that's about what I would have thought. Supposedly the factory spec is -1.9, but it no doubt varies and may drift. Somebody posted a recent SC invoice stating a "bolt was added to reduce camber, addressing the tire wear complaint.." or something. Anyway, I am going to try to get it to -1.4-1.5 and only slightly toe-in on the align. Will be curious where it is today, for the record.
     
  5. 100thMonkey

    100thMonkey Member

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    I got ahead of this on our P85+. having put 12K miles on a P85 with 21's, I was not all that happy with the performance of them in this generally cold and wet climate, so I became less resistant to going with 19's (even though I prefer the look of the 21's). the P85+ was a loaner, had a few thousand miles on it and already some inside wear on the rears. I had the alignment done right away and switched to MXM4's. since putting 19's on the P85+ and putting about 6K miles on them, there is no measurable difference in inside rear wear. I have the lowering set to 45 MPH. really hoping that someone comes out with all seasons for the 21's but for now I'm sticking with the 19's. I'm not sure if it's the additional conformity of the 19's or the alignment I had done but I'm not messing with success, I'm just happy that the tires are holding up well so far and I'm happy with the performance of the 19's, they seem to be the best of both worlds for the climate we have here.

    considering that it takes a barrel of oil to make a tire, this issue is of importance to our family from an economic, convenience and environmental perspective.
     
  6. slipdrive

    slipdrive Member

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    From new in August, I put 2.5K on, rotated and another 3.5K then Blizzaks for the winter. All the tread looked fine. Then the Goodyears back on at 12K and by 14K the rears were thrashed. It's almost like something intervened with alignment. Will get it in to the SC this week.
     
  7. vgrinshpun

    vgrinshpun Active Member

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    #7 vgrinshpun, May 18, 2014
    Last edited: May 18, 2014
    I just have had car returned after SC visit due to similar issue - the rears were worn to the cords after I've put summer tires on in only 1,700 miles of driving. My setup is slightly different as I have "+", so rear tires are wider (265 mm) which probably exacerbates the inside of the tire wear issue. I was really caught by surprise with this, because my winter set (19" Blizzak LM60) did not wear that much, and did not exhibit the increased wear of the inside shoulder of the rear tires. I had previous alignment done last November, and all of the numbers were within specs. (incidentally, the specs could be found on-line in the manual, on page 121, and I suggest you print them out for your edification, and verification that everything is aligned properly after the SC visit).

    It turns out that my rear camber measured at -3 deg. left and -3.25 deg. right, while rear toe was also out of spec -0.78 deg. left and -.37 deg. right. After discussing this with the SC manager in detail, it turns out that my rear ride height sensors were somehow not programmed right and the rear was riding very low while in normal, and even lower when the car was lowering at highway speed. The SC manager was not sure how that have happened, because the sensors were obviously programmed correctly during the winter, when the car was wearing Blizzaks. His theory was that something happened during the installation of the 5.9 upgrade on my car due to one-off software glitch. He did confirm that lowering the ride increases camber that was set at "normal" height. My camber was probably slightly off to begin with, and that was further amplified by the rear sensors keeping the rear height very low.

    Interestingly enough I have noticed that I was flushed with high beams by the drivers moving in opposite direction at night lately, apparently because the rear was riding so low that my headlights were lighting the sky. I also noticed that my rear kind off looked low, but did not pay enough attention. You can check this while car is parked. When rear is in normal "normal" position the top of the tire should be below the lower edge of the fender. Before this was fixed, however, the top of my rear tires was actually higher than the lower edge of the fender, i.e. the top of the rear tire was hidden in the wheel well.

    I asked my SC manager to set rear camber to the lower part of the tolerance band, i.e. between -1.4 and -1.75 deg. After alignment my rear camber is -1.43 deg. left and -1.77 deg. right. I was told by SC manager that this was the lowest possible in my car. Since rears were worn prematurely due to the issue with the programming of rear sensors my rear tires were replaced with new ones without charge.
     
  8. slipdrive

    slipdrive Member

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    Thanks! That's very interesting indeed, and sort of fits with my feeling that 5.9 might have been involved. I'll keep that in mind when discussing with the SC. They have been fantastic about everything, but this one surprised me a bit.
     
  9. FlasherZ

    FlasherZ Sig Model S + Sig Model X + Model 3 Resv

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    lolachampcar said that using a longer UCA worked only to a smallish degree until toe links become an issue.
     
  10. zwede

    zwede 2013 P85+

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    Maybe he'll chime in, but I remember he said he made 0.25" longer arms and got his camber to under 1 dgr with the stock toe links.
     
  11. linkster

    linkster Member

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    Generally speaking, the UL 210's will remove almost 1 degree and the 250's will remove more than 1 degree. However, the 250's start to push the eccentric TL adjustment to its maximum range.

    Chris1Howell is currently working on supplying longer ULs.
     
  12. lolachampcar

    lolachampcar Active Member

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  13. LuckyLuke

    LuckyLuke Model S P85DL

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    Are those UL 210 or 250 actual Tesla part names or aftermarket/self named?
     
  14. linkster

    linkster Member

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    Lucky,

    Self named abbreviations.

    So very glad to see the suspensionMAVEN (post #12) is now on this thread!!
     
  15. rlcordeiro

    rlcordeiro Member

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    I read about the Camber bolts on another thread and had the SC put them on at my last service. Any idea how much they correct the negative camber.
     
  16. lolachampcar

    lolachampcar Active Member

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    It depends how the original bolts were biased (they had slop too; just less), it can be around 0.6 change.
     
  17. David Leidy

    David Leidy Member

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    New tires 3 months ago, now 6k miles later my left rear tire is to the cords. They replaced the camber bolts and aligned it at the last visit, but I think it's obvious that they did something wrong on the left. Compare the left and right wear, and it's obvious. IMG_4229.JPG IMG_4230.JPG
     
  18. Merrill

    Merrill Active Member

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    Did you get a before and after, my toe on the rear was very much to the positive on both, but have not worn to the steel belts. They need to redo the alignment and ask for a before and after reading.
     
  19. HyperMiler

    HyperMiler Member

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    Noticing that there is wear on both shoulders of each tyre, what is the pressure you are running the 21s at?
     
  20. zwede

    zwede 2013 P85+

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    I bet you have toe-out. That is not a camber issue.
     

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