Negative Camber in the Rear and Expensive Tires

[rammer91]

All great information here on the forum about tire wear and 19's vs 21's. This is honestly my last remaining hesitation about the Model S for me, since I do about 25,000 miles per year.

From everything I've gather from other threads and this one, this seems to be an issue that will simply be a part of Model S ownership that has to be factored into the decision making process. Has anybody heard of any plans from Tesla to address this issue long term? I'm guessing not . . they are focused on bigger things right now. Unfortunately for me, the value proposition of reduced maintenance costs dissipates when one has to replace tires so often.

That said, I still love the Model S and will hopefully have one soon! Just aching over whether to go with 19's or 21's, when I really want 21's!

 

[lolachampcar]

You can go with 21s. It is just a matter of getting comfortable with having the upper control arms in the rear changed and having toe set near zero. I'm at over 17K miles on PS2s and should make it to 20K. Replace the PS2s with Pilot Super Sports on the first cycle and you'll see even better wear/longevity.

Orrrrrrrrr
You could by my P85+ which already has all this done Gotta make room for the newly ordered P85D.

 

[rammer91]

Ha ha! That's awesome you've already ordered the P85D.

Nice . . . I'd love to know what's involved in changing the rear upper control arms . . . is it a kit? Based on some of your other posts something tells me you know a bit more than the average Joe when it comes to customizing your car. Something like that would be over my head, although I wouldn't be averse to paying someone to do it. That said, I'm sure it voids some sort of warranty. I'll search around the forum.

I'm curious . . . a layman like me would logically think that AWD would more evenly distribute the forces on all four tires rather than concentrating them on the rear two. Could this possibly help increase tire life (assuming everything is properly aligned)?

 

[lolachampcar]

I doubt usage is the primary driver of wear.

WRT the arms, I made some for my needs but declined to produce them for liability reasons. The people over at OpenEVSE picked up the ball and had some very nice links made. They are easily installed by any competent alignment shop (which is handy as you have to reset rear toe when you change to the longer upper links).

 

[linkster]

Gotta make room for the newly ordered P85D.

Thanks ALOT for "rubbing-it-in" about your incoming insanely quick P85D.

And i am down here having difficultly just paying for the electrons to power our dinosaur P85 after the drubbing I have been taking lately in the market including TSLA.

Enjoy your new toy !

Btw, currently at 36,000 miles on original 21 Conti's. The fronts will easily go 40 and the rears to 45 due to your guidance on this forum.


rammer,
FYI, I have purchased/swapped 6 used 21's over the past year and THREE were bent. Glad you took the time to read through this and possibly related threads. Good-luck with your decision.

 

[ra-san]

Lolachampccr, do you have any info about the P85D suspension changes from the P85+? My current plan is just to get an initial alignment check and make sure everything is in spec but at minimal toe and camber and see how it goes. Interested in your plans.

 

[rammer91]

Thanks ALOT for "rubbing-it-in" about your incoming insanely quick P85D.

And i am down here having difficultly just paying for the electrons to power our dinosaur P85 after the drubbing I have been taking lately in the market including TSLA.

Enjoy your new toy !

Btw, currently at 36,000 miles on original 21 Conti's. The fronts will easily go 40 and the rears to 45 due to your guidance on this forum.


rammer,
I have purchased/swapped 6 used 21's over the past year and THREE were bent. Glad you took the time to read through this and possibly related threads. Good-luck with your decision.

Linkster, thanks for the response. I'm curious . . did you do the upper control arm replacement that lolchampcar has detailed in these forums? If so, the tire life you are getting is an awesome result!

Also, when you mentioned you purchased/swapped used 21s and three were bent . . .are you saying these rims bend easily? I was just going to get the 21s from the factor so I assume they wouldn't be bent.

Sorry if my questions are a bit dense. A noob to these forums and generally not a car expert. Cheers and thanks for the info.

 

[linkster]

Yes, I am using a slightly modded version of lola's UL design. The high cambered S will eat 21's which are far less forgiving than 19's no matter what toe setting is deployed.

The 21 wheels aren't structurally weaker (generally speaking) than the 19's. It's just that a 245/35-21 with a 2.25" nominal compressed sidewall height is no where near enough to absorb sharp large bumps (let alone pot holes) and will only provide an acceptable service life when driven on nearly perfect roads with 2 5/8 ton auto.

 

[lolachampcar]

Lolachampccr, do you have any info about the P85D suspension changes from the P85+? My current plan is just to get an initial alignment check and make sure everything is in spec but at minimal toe and camber and see how it goes. Interested in your plans.

I checked with Tesla and they changed the shock damping values but not the spring rate of the air springs. My hopes are that the damping changes will be sufficient to compensate for the soft disconnected feeling (for my tastes) of the air springs. If not, I'll have to replace the air springs with coil springs.

WRT the rest of the suspension, I would guess they have changed nothing on the rear that would affect negative camber. Maybe they will surprise all of us and make rear camber adjustable but I suspect they will just leave it the way it is. I'll be doing upper links on the PD.

 

[tengk]

Does anyone know with the announcement of the AWD Model S "D", if the uneven tire wear from the cambering will now also cause the same issue on the front tires, or will the tires wear more evenly (i.e last longer) because the torque will be distributed more equally?

 

[lolachampcar]

The existing zero scrub radius front suspension geometry has more than enough room for the AWD drive shaft and different upright. The pick up points on the chassis will not change so I think it is reasonable to assume that there will be the existing/current MS capability to set front toe and camber. For this reason, I do not think you will see any significant difference in front tire wear attributable to the issues found on the rear.

I believe the high rear tire wear on the inside edge is alignment related and not weight/torque related so I do not anticipate that problem going away with the PD or AWD.

None of this speaks to the even tire wear that comes from aggressively using the huge acceleration available in either the P or PD.

 

[offset]

I've installed the OpenEV links that were designed by lolachampcar. However I'm having a hell of a time finding a good alignment shop. No one has the vehicle listed in their machines, and when they try to pair it up with something similar the car drives straight but the steering wheel is not centered. Is there a specific vehicle I need to match it up with? BMW 7 series? is there a specific machine that we need to request? Hunter Vs _______? Is there a magic alignment sheet that I can print out and take with me to another shop maybe and say I want this: ____________?

I gotta say I'm in love with this car, if I can fix this tire issue I would love it even more!

 

[zwede]

The alignment specs are in the owners manual. You can pull it up on the center screen for them.

As for the steering wheel not being straight: That has nothing to so with specs, that's just sloppy work by the shop.

 

[Luis Mengual]

Dear all,

What about this thread regarding New version "D". New 4 wheels-drive will take more care on the rear tires? they will have fixed this issue despite near 700hp?

 

[yobigd20]

Dear all,

What about this thread regarding New version "D". New 4 wheels-drive will take more care on the rear tires? they will have fixed this issue despite near 700hp?

While lolchamp holds the most expertise here and his opinion if I recall from above is that the problem won't change in AWD versions (unless suspension is changed to fix this of course), I would sort of agree and disagree (I'm a noob and hold no expertise in this field) as I would have thought that at a minimum the distributed torque across all wheels would have "prolonged" the problem. Certainly if negative camber exists and wheels are not aligned and there is toe out on the rear, I would think that maybe the problem just would've taken 30-40% longer to appear. The rear motor is way more powerful than the front still though so under heavy accel I still expect the rear to hold much more torque than the front so not 50/50 hence lolchamp is right the problem isn't going to go away if the alignment is still susceptible to being knocked out. That of course referring mostly to the P85D. The S85D uses equal size motors on front and rear so more 50/50 and much less torque on the rear.

So my opinion is that on the P85D the problem is still going to be pretty bad especially with 21s but that the S85D will fair much much better. Time will tell I guess....

 

[linkster]

offset,

Good move on installing OpenEV's .210" long, i-beam design ULs as they will greatly reduce pre-mature inside rear tire wear, increase your efficiency (with proper alignment as I am around 275ish wh/mi. at 65-70mph this past summer with the A/C) and will easily pay for the themselves. You can PM me if you would like additional non-spec strategies for extending your tire life.

btw, we love our P85 too, resolving this tire issue and obtaining long life from our tires has made ownership that much sweeter

 

[rammer91]

Offset, Linkster, or anyone,

I'll be placing my order for S85D soon and have decided that I will get the 21's and be prepared for this potential inside tire wear issue. That said, I am curious at the difficulty level you encountered in replacing the arms (assuming you did it yourself) because I would be willing to try this myself. I am not a car expert, however, I'm pretty handy at things in general and can perform straightforward repairs, etc and figure things out. As an example, I typically change my own brake pads on my vehicles which involves much more than the average person would take on.

Looking at videos online on how to change upper control arms on a BMW, the task doesn't look very difficult and it doesn't appear that you need to remove a lot of things from the vehicle. In fact, it seems very straightforward, assuming you have the right tools.

Am I being overly ambitious here? Wondering if I should find a shop to do it, or if I can tackle this on my own.

Thanks!!

Eric

 

[rammer91]

Linkster,

That is fantastic, thank you! Yes, very familiar with proper jack/stand procedures and am typically over cautious.

When one orders the part (and, I assume, the specialized tool since I don't have one) from Openevse, does it come with instructions that are more detailed than the general instructions they have on their website? Their general instructions seem to oversimplify and don't capture the nuances that are always involved in projects like these.

Also, forgive my ignorance, but just to make sure I understand some of the things you said: A) when you say "UL" bolt, does "UL" refer to "Upper Link", and B) when you mention to put the suspension under load prior to fully tightening the UL bolt, are you saying to somewhat tighten the UL bolt, then lower the vehicle back down so its full weight rests on the ground, then reach around the wheel to fully tighten the bolt?

Some of this will likely become obvious once I read the detailed directions (if the part comes with them) or as I get into the project.

Can't thank you enough. I'm excited about this project!

 

[linkster]

rammer,
Feel free to PM me, where I will be more comfortable answering your above specific questions. I am concerned that someone who doesn't have your experience level may attempt to follow along with this upgrade without fully understanding the beyond catastrophic results that could result from an improper install.

 

[KevinMS]

First of all, thanks to lolachampcar and Chris1Howell for putting out a solution to the excessive negative camber. I had the SC do a four wheel alignment in June where they said that my camber was out of spec (-2.2 on both sides at normal ride height), and that they would order camber bolts to correct it. I called the SC to schedule the second annual service this week and asked about the camber bolts. They said that the bolts wouldn't be installed at this time with no further explanation. Meanwhile, the rear tires have worn through the cords again.

I have one question about OpenEV's UCAs before I buy a set. The mount for the ride height sensor linkage appears to be centered on both the stock and the lengthened arm instead of offset towards the frame by 0.105 inch. If that is correct, doesn't that impact the calibration on the ride height?