Checked Alignment: The Good, The Bad, The Ugly

[lolachampcar]

DIL,
I'm narrowing in on my ideal and it looks something like a P85 with P+ lower a-arms on coil springs lowered 1" and 20" running PSS. I'm thinking I would like that better than my P+ but then you loose the ability to raise the car over obstacles. I can live with this here in South FL.

oh and 0.1 degree of toe in and 1.2 degrees of negative camber in the rear.

 

[100thMonkey]

thanks to the heads up from you all, lolachampcar's in particular, I had my alignment checked today at 3,500 miles. I was not given a read out, but was told that indeed it was toe'd out. happy I did it now before a bunch of miles and toasted tires!

BTW, I asked a local Les Schwab to check the alignment, made an appointment, when I got there they got nervous. the manager called the regional manager who said: "do not touch that car, it's too exotic and finicky." guess I won't be doing business with them, too bad, they are around the corner from my house.

 

[Gizmotoy]

BTW, I asked a local Les Schwab to check the alignment, made an appointment, when I got there they got nervous. the manager called the regional manager who said: "do not touch that car, it's too exotic and finicky." guess I won't be doing business with them, too bad, they are around the corner from my house.

I wonder if the word is out that the cars have alignment issues and they don't want to get involved, or if the regional manager was just clueless.

 

[jerry33]

I wonder if the word is out that the cars have alignment issues and they don't want to get involved, or if the regional manager was just clueless.

Generally those kind of alignment places don't have folks that know much about alignment. They just read the numbers and make the adjustments. This works reasonably well for $20K and under cars. It doesn't work so well for better cars. The best thing is to find a frame shop that deals in high end cars and have them do the alignment. Their equipment is likely to be better calibrated.

 

[lolachampcar]

One vote for clueless.... The car could not be more standard under the wheel wells. If you could not see the "Ts" on the castings you would think you were looking at a seven series

 

[jerry33]

One vote for clueless.... The car could not be more standard under the wheel wells. If you could not see the "Ts" on the castings you would think you were looking at a seven series

My guess is that they don't do seven series either

 

[Gizmotoy]

Generally those kind of alignment places don't have folks that know much about alignment. They just read the numbers and make the adjustments. This works reasonably well for $20K and under cars. It doesn't work so well for better cars. The best thing is to find a frame shop that deals in high end cars and have them do the alignment. Their equipment is likely to be better calibrated.

Pretty much true. I had a fantastic guy back in Ohio that works on race teams that owned a performance alignment shop. I'd always take my cars there. It was more expensive, but worth it. I'll need to find a new place now that I've moved to the Bay Area.

 

[hoopty_yo]

Generally those kind of alignment places don't have folks that know much about alignment. They just read the numbers and make the adjustments. This works reasonably well for $20K and under cars. It doesn't work so well for better cars. The best thing is to find a frame shop that deals in high end cars and have them do the alignment. Their equipment is likely to be better calibrated.

Well that's a generalized statement if I've ever seen one. I, for one, was never afraid to align anything and enjoyed a challenge as long as I was given the proper amount of time to do it. And they sure don't spend 8 hours a day for a week in class going over alignment theory and customer concerns vs. the reality of what's possible for a particular vehicle modification or wheel/tire package. Not to say that every tech is certified by Les Schwab, but many of them are. You will find lazy people in any field.

As for the last two alignment sheets posted: The second to last had the rear camber out of spec. I though I asked if there was an adjustment in another thread, but I can't remember.

I did notice on the last one posted that the toe was adjusted in on the high side. That's the same thing I would do to compensate for the negative camber if a customer was still experiencing inner edge wear. On the down side, this will cause more rolling resistance with the two combined. Ideally if there was an adjustment for rear camber, I would push it up as high as recommended (-1.3 I think I saw) and adjust the toe to dead-center of spec. The trade-off on that, is it may induce oversteer during a threshold lateral traction maneuver. There is a happy place somewhere between handling, tire wear and range, but you can't have it all.

 

[ACDriveMotor]

I kind of figured it wasn't. It's just that the wear on the 21"s makes it so much more obvious there is a problem. I hate to think that the first thing I need to do after I take delivery is get the thing up on a rack for an alignment, but it's looking like that'll be required.

I asked for an alignment check as part of delivery prep. Given this thread this doesn't seem like an unreasonable request.

 

[bareyb]

Pretty much true. I had a fantastic guy back in Ohio that works on race teams that owned a performance alignment shop. I'd always take my cars there. It was more expensive, but worth it. I'll need to find a new place now that I've moved to the Bay Area.

Custom Alignment in Mountain View used to be the go to place for alignments when I had my Corvette. It's been a few years but they might be worth looking into.

ETA: They seem to still be getting good reviews on YELP: Custom Alignment-Balance Brakes - Mountain View, CA

 

[dsm363]

Is it worth having a Model S checked again for alignment after it travels in an enclosed car transport for a long distance (2,000+ miles)?

 

[DIL]

Custom Alignment in Mountain View used to be the go to place for alignments when I had my Corvette. It's been a few years but they might be worth looking into.

ETA: They seem to still be getting good reviews on YELP: Custom Alignment-Balance Brakes - Mountain View, CA

Thanks for the tip!

 

[bareyb]

Is it worth having a Model S checked again for alignment after it travels in an enclosed car transport for a long distance (2,000+ miles)?

I called and made an appointment at the nearest Tesla service center and they said they'd check it for free. I'm not absolutely sure there's anything wrong with mine, but it is acting kind of funny when I floor it (back end feels kind of squirrely). I've read that in such cases excessive Toe could be the culprit. On the other hand it may just be some form of Torque steer I'm feeling. I don't notice anything when I'm just driving it normally, but I thought it was worth a look.

 

[FlasherZ]

[moved here from a different thread, this is a better place...]

I took the car to a local shop to simply measure the alignment this morning.

Rear camber is -2.0 (L), -2.6 (R) in standard suspension height. As we run > 70% of our miles in low suspension mode, that negative camber effect is going to be higher.

Rear toe is -0.13 (OUT, L) and +0.12 (IN, R), for a total toe of -0.01 (minimal). A slight bit of crabwalking, perhaps, but no significant toe-out.

Front camber was -0.7 (L), -0.9 (R), well within specs; front toe was +0.79 (IN, L) and -0.81 (OUT, R), for a total toe of -0.02... wheel may have been slightly turned.

Everyone who looks at the rear of the car comments about the negative camber, it's extremely obvious.

I'll let lolachampcar provide his assessment, but it seems like toe isn't my issue and it appears it's likely the extreme camber.

Tomorrow, we're putting the 19" tires on for winter, the bigger sidewalls should help a bit but it's clear Tesla will need to address the camber to keep me from shredding these tires every 4,000 miles or so.

 

[Dreamin]

Wow, your car must look like it's driving down the road diagonally.

You should get your alignment fixed. It may 'feel' fine as the total toe it fine, but the individual toe is way of our spec.
Your front tires are going to shred themselves with that much toe (in or out). And toe out in the rear is a safety concern.

 

[FlasherZ]

Wow, your car must look like it's driving down the road diagonally.

You should get your alignment fixed. It may 'feel' fine as the total toe it fine, but the individual toe is way of our spec.
Your front tires are going to shred themselves with that much toe (in or out). And toe out in the rear is a safety concern.

The car does not look like it's driving diagonally. The thrust angle is 0.12, well within Tesla's 0.00 +/- 0.30 spec.

As for front toe, that's why I said "wheel may have been slightly turned", and I suspect it was. This was not a precise alignment adjustment and was a quick, 20 minute check. I was more interested in the rear specs than the front. As a result, we weren't terribly precise on the front, the +0.79 and -0.81 offset each other, and are likely the result of the steering wheel being slightly turned.

Both front toe measurements offset each other, and both rear toe measurements offset each other to +0.02 and -0.01, respectively. As a result, they won't be shredding tires. This rear toe means a slight bit of crab walking (although thrust angle is within specs); these front toe measurements would pull the car to the right (but that doesn't happen, hence my belief it was steering wheel turned slightly for such a high front toe measurement).

The service center will be looking at it once again when they collect the car tomorrow. I'll look for their report too.

I'll share lolachampcar's response (with his permission, of course):

Lots of thoughts and here they are in no particular order.

Front camber is nice being around -1 degree (actually, a little less). The right has 20% more.

Rear camber is normal for air with the right having 30% more. I've yet to hear any reasonable expiation for so much "cross camber" or difference between right and left for MS. The service tech at Dania had no idea and confirmed my thoughts when he said he never saw that much on MBs (his previous 10 years in the business).

I've found that running two degrees of camber in the rear will tear up tires even with modest toe in. I knew the second I looked at the back of my car that I was going to have to fix it. I knew the second I looked at the suspension that I was going to have to make my own arms to fix it.

The thrust angle and front toe values combine together to make sense. The front toes say that the steering wheel was just slightly turned or the machine is just slightly out of calibration on the front sensors. Add the two front toe values together and you come up with 0.02 degrees of toe which, again, is basically zero as it is within the measurement accuracy of the machine. If the wheel is not offset while driving down the road, you are perfectly fine. Zero toe on the front is perfectly fine as well and very good for range.

The thrust angle means the car was crabbing slightly. Total toe in was reasonably good at near zero. Given that the machine "saw" the car centerline as off the centerline of both the front and rear wheels, I wonder if the machine was having a hard time picking up the car's centerline. It will be interesting to see if the Service Center sees the exact same thing.

Near zero toe in in the rear says camber is driving all your issues. As for how bad it can drive wear, start by thinking about the tire as a ridged rectangle in cross section. Tilting that cross section in by 2.5 degrees puts all the load on a corner (inside shoulder). Tires are not 100% ridged so they will spread the load. The thinner/stiffer the tire side wall, the less it spreads the load.

In summary, you have confirmed that you have big rear camber and you do not have toe out in the rear. You're eating tires without toe out so dumping camber is your only hope that I can see. Who knows; maybe the geniuses at Tesla will come up with some other explanation and fix for this problem. If they do, hats off to them as I'm not aware of one and they will have pulled yet another one over on the likes of BMW, MB, Acura and Audi.

Thanks to lolachampcar for all his input and help here! I'm confident we will have a fix at some point, whether it's Tesla generating a special suspension kit to reduce camber, or me purchasing some links from lolachampcar to pull that camber out.

 

[Dreamin]

The car does not look like it's driving diagonally.

No offense was meant to you or your car by this comment. :smile:

As for front toe, that's why I said "wheel may have been slightly turned"

Read that, but it didn't make sense. The alignment computer tells the operator to turn the wheel lock to lock and then to center and takes the reading - to prevent exactly this. You pulled onto the alignment rack, the guy attached the harness and just took the measurement? And as far as the alignment machine being out of calibration, that's a lot out of calibration.

The thrust angle is 0.12, well within Tesla's 0.00 +/- 0.30 spec.

Thrust angle was not provided above. But accounting for thrust angle, yes your rear toe is fine.

We're all pretty sensitive to toe out issues now... just trying to be helpful...

 

[lolachampcar]

hoopty,

That is some interesting insight. The idea of running more toe in for the rear to effectively "pull in" the outside of the rear tires into the contact patch and reduce shoulder wear is interesting. That is the first time I have heard this and it may help explain some discrepancy we have in our tire wear survey. I did have a situation on my P+ after replacing the upper links where we could not get enough toe out on one side of the car. As a result, I ran something like 0.45 degrees of total toe in for a few days. The result was a small loss in range coupled with a more stable car on the highway (less tendency to follow grooves). We ended up loosening the sub-frame and allowing it to snap back straight with the car at which point equal toe adjustment range was restored and toe was set to 0.1 in. Range returned as did the tendency to follow highway imperfections.

I have noticed that BMWs do carry a lot of toe in on the rear which would bolster the toe in helps offset camber information.

Lastly, the coil spring MS sits a tad bit higher than the air car and is allowed somewhere around minus one degree of camber. If it is within spec. you can bet Tesla certified MS at the lowest end of this spec (least amount of negative camber) when did their FMVSS 126 compliance testing. Thus my thoughts are that -1.0 in the back is perfectly safe.

I did notice on the last one posted that the toe was adjusted in on the high side. That's the same thing I would do to compensate for the negative camber if a customer was still experiencing inner edge wear. On the down side, this will cause more rolling resistance with the two combined. Ideally if there was an adjustment for rear camber, I would push it up as high as recommended (-1.3 I think I saw) and adjust the toe to dead-center of spec. The trade-off on that, is it may induce oversteer during a threshold lateral traction maneuver. There is a happy place somewhere between handling, tire wear and range, but you can't have it all.

BTW, I really do not have much use for the snippy side of forums but information like this and the ability to work with many people of vastly varied backgrounds to figure out a difficult problem is FANTASTIC.

 

[Gizmotoy]

I asked for an alignment check as part of delivery prep. Given this thread this doesn't seem like an unreasonable request.

I see your delivery date was yesterday. Did you get the impression they actually checked it? I might do the same.

Custom Alignment in Mountain View used to be the go to place for alignments when I had my Corvette. It's been a few years but they might be worth looking into.
ETA: They seem to still be getting good reviews on YELP: Custom Alignment-Balance Brakes - Mountain View, CA

Thanks for the suggestion. From the reviews, it sounds like it's run by a stubborn older gentleman who is not afraid to tell you you're wrong, just like the place I used to go in Ohio :biggrin:. I'll certainly check it out, it's just down the road from me.

 

[hoopty_yo]

I have noticed that BMWs do carry a lot of toe in on the rear which would bolster the toe in helps offset camber information.

BMWs were actually the vehicles that I noticed the correlation between large negative camber numbers and higher toe-in specs, generally .40-.45 degrees if I remember. Most road-going grocery getters tend to be .15-ish total toe and -.8 to -1.4 rear camber, which leads me to believe that some negative camber is necessary for stability. My hypermiler backs this up as it is set close to zeros across the board and can be a little twitchy. Though with skinny balloon tires, it isn't a slot car either.