Aresh

Thank you very much. Let's see what the dealer says.

ATL_MB

OP - You don't say where you are located. I think a better way of going about this is to ask if there is anyone on the board who can recommend someone in your area. Alignment really requires someone who knows what they are doing - the dealer I use in Atlanta is outstanding in just about every way, but I still go to Butler's Tire for alignments. It is a bit of a black art - how many F1 teams struggle with setting up their car? - and sometimes you need a magician, not a technician. (I'm not knocking roadtalontsi at all - I am no expert, but what he says makes sense to me; I am just not confident that telling a technician at the dealer what to do is going to help here.)

Aresh

thanks for your input. I am locating on long island, NY. I had the alignment done at the dealer a week ago, so going back they wont charge me. I had the car aligned at three different shops already with no success. So tomorrow morning im going to call the dealer up and tell them what roadtalontsi said. I spoke to the tech today and he recommended I get the kmac kit if it helps adjust the camber. But after reading what roadtalontsi said, im hoping they will follow his directions.

roadtalontsi

the kmac kit will help reduce the camber even more but you'll be pretty close to -2.00 camber which is fine. I'd consider anything more negative than -2.30 camber pointless if its not being tracked regularly, it wont do anything but kill tires faster. What tires do you have on the car? as long as they are something decent - not falken/yokohama/kumho they should wear just ever so slightly more on the inside - by the time the inside goes bald the rest of the tread will be at the wear bars. Our cars are very heavy and dont take kindly to crappy cheap tires.

Aresh

I hear you, right now all I care is for the car to go straight for once. I dropped the car off. Gave them your instructions. Literally printed them out haha. Hoping for the best.

Aresh

I just want to say, thank you, thank you so much. My car is finally aligned and straight. Finally!!!!

Mort

Glad to hear you finally got your alignment corrected and that the car is driving straight without pulling.

Do you have the final spec sheet and would you be willing to share it with us? TKS

Aresh

Here you go.

roadtalontsi

you are welcome sir, glad they listened and you had great results. I've been doing alignments almost exclusively on benz's for about 8yrs now and most people are clueless as to how to get them to drive good. enjoy.

abcut973

So did they use the camber bolts?

Mort

Thanks to Aresh for this thread and posting up his alignment sheets and following through after he got his alignment performed to his liking.

Also, many thanks to roadtalontsi for talking us through this issue (and lots of other ones),very much appreciated.

Aresh

No problem, hopefully this will help others with similar issues. I read many threads regarding this problem but no solid answers.

noodleman

did you get the front kit and/or the rear kmac kit to fix your issue?

Aresh

Just Camber bolts.

Ingenieur

both printouts look OK to me
the first had camber out of spec by ~0.1 deg
the second brought it within spec, changed about 0.3 deg but still over the mid point of 2 deg, but it pulled caster out of spec
I doubt I could feel these differences

what is interesting is the lowering amounts/ride heights
do you have a pre- lowering spring alignment sheet?

front spec is ~ -8 mm or so (mine avg -13.5 and within spec of ~-15 to 0)
rear ~ 0 mm (mine avg -3 and within spec of ~ +3 to -8)
(the mm is estimated since spec is given in degrees and it's not linear)
mine's a 2009 and the specs for your car are different, eg, my front camber ~1.5 and yours is 2, rear, mine 1.5 and yours 2.3

yours
F -26 mm avg
R -20 mm avg

using my stock for a baseline lowering =
F ~ -13 - (-26) ~ 13 mm of drop
R ~ -3 - (-20) ~ 17 mm of drop

it looks like the H&R may drop the front a bit more?
Eibachs did this intentionally on some applications to shift weight rearward

It would be interesting to have the numbers for the same car with the same fuel load

Aresh

I don't have pre lowering one. Some things to consider if you haven't already is I have 2012 coupe. Maybe the sedan is setup a bit different?

roadtalontsi

saying the change is .3 deg is really misleading. That rack reads in degrees and minutes. It changed almost 30 minutes. 60 minutes in a degree. so infact it was actually more like 1/2 of a degree. As for the caster change that is to give the car a pull to the left to counter act the road crown. although it is technically not "in specs" they have listed. caster is a non wearing tire angle. Having this pull present when on a road/city with crowned roads that it is needed to make the car drive straight will help wear the tires much better. Other wise you are always holding the steering wheel and having the wheels turned to counter act the pull. You may not think such a little change can be felt but it can. Depending on the car, each car is different usually a pull of .3 or more can be noticed.

Also the mm calculation is based on the angle of the front lower control arm and rear axle using a special tool - romess gauge. So if your using a tape measure or any other way your results will vary quite a bit. I'll be doing an alignment laster this week probably on my 10' sedan with kw's - not lowered very much and ill post up the spec sheets

Ingenieur

not accurate
change in the front:
L from 2 deg 30' to 2 deg 17' = 13' ~ 0.216 deg
R from 2 deg 33' to 2 deg 13' = 20' ~ 0.333 deg
I used the avg of ~ 0.3 deg or 18', very close
avg is 0.275 +/- so in fact not 0.5 deg or 30', it is actually LESS than my estimate of 0.3 deg, NOT 0.5 deg

loading (ie passengers) will change it more than that

the rear did not change (within the error of repeatability) and is within spec and on the 'flat' side

They did not adjust caster to counter road crown, it was a consequence of the camber adjustment. The cross caster is a deg off and both sides are out of spec where as they were in spec and essentially equal before. (does it even have caster adjustment? most BMW's don't)

I would not have done the bolts for such a minute (pun intended) change. I would have observed tire wear patterns and tried to equalize/mimimize it with toe compensation (perhaps a bit on the 'straight' side of spec). But either way those differences are moot and imho opinion would not be felt.

As far as the ride height spec, it is sensitive but should be repeatable (fuel load, etc.), My estimates were based of fitting his numbers and mine to a geometric arc equation. That is why I wish he had pre-spring numbers it would be interesting to see the relative drop.

I learned to do my own alignment, no pro by a long shot but understand the procedure and goal. My e46 required weighting: 68 kg each front seat, 68 kg center rear and 21 kg trunk with full tank of fuel. BMW does measure rife ht with a ruler, floor to lip. pg 31.
the following doc has some good info (although it states the M3 does not need weighted when you pull up the software it says it does?)
http://www.google.com/url?sa=t&rct=j...4dHPOZhxQePmnA

roadtalontsi

the reduction of caster on the left side is from pulling the camber bolt in which also made it go more positive camber. on the right side however pulling the right torque strut arm caused an increase in caster and more positive camber as well. thus giving it the approx 1 degree offset in caster. This was my plan as he said the road crowns are bad there. Unless you've lived where they are bad you dont know. In texas they vary from 5-10 degrees. Sure you could adjust the toe to change the steering wheel position to being straight as your driving straight but that doesnt account for the fact that both tires be turned slightly to "climb" up the crown. there are 4 adjustment points on the front end. left and right , torque strut arms and lower control arms. the torque strut arms change caster more than camber but change both, the control arms change camber more but also change caster. you have the stock bolt position, pulled in or pushed out with adjustment bolt kit (3) positions you can make at any/all of the 4 spots. The rear only has caster adjustment - on a regular c63 sedan/coupe. This is what makes benz alignments very complicated for most people to grasp. Sure he could've just pulled every arm in and lost say .30 minutes of camber left and right but it still wouldnt drive all that great from the road crown. Trust me if Aresh can feel the difference and he is no alignment pro, you can notice the pull.

as for the .3 degree etc... ya you got me there, I didnt feel like looking at the specs again all sideways like. non of the benz's require weight either when doing the alignments. Only the sls needs weight when tightening control arm bolts.

Ingenieur

e = superelevation or 'crown' is defined by AASHTO and is 0.06 m/m (ft/ft) max (6% slope), but usually less...

5 deg = 11.4% and 10 deg = 17% slop
6% slope = 3.4 deg
if a road 5 or 10 degrees there is a road design issue and this is dangerous
water will flow well on a rough surface at 3% or so (sewer lines range from 1 to 2% for reference)

say you have a 24' wide road (2 lanes same direction) at the max 6%
crown rise/ht = sin (arctan 0.06) x 24' x 12"/ft = 17"
from the edge to the center the road would rise 17", not too steep

if 10 deg = 24 x 12 x sin(10) = 50" of rise, no way... >4'?
50/(24 x 12) x 100 = 17% slope, way more than needed


not trying to argue, just to make the point his first alignment was good

Mort

Aresh's car is lowered and the original alignment was pulling to the right. He had an alignment performed to reduce the pull to the right but it did not correct for the pull to the right. He redid the alignment to remove the pull. Changing the caster to be more positive on the right side and increasing pull to the left negated the cars tendency to pull to the right and the driver of the car seems to be satisfied. So yes the alignment was necessary as was putting the cars cross caster slightly out of tolerance to achieve that goal.

Ingenieur

if you look at the second printout the caster was the same before and after...it was pushed out by the camber bolts, they did not adjust it

it appeared they did camber bolts to reduce it ~0.3 deg??

DuaneC63

The factory suspension has no front camber/caster adjustment and the rear has no camber adjustment. You need camber/caster bolts (AKA crash bolts in the front). For the rear you need upper rear adjustable control arms. Any good alignment shop will have the front crash bolts. Call ACG in San Diego for the rear control arms.

roadtalontsi

since this got bumped i just noticed this reply. When you pull the camber bolts in you lose caster. So if all they did was pull in left and right cambers you wouldn't be causing a caster pull, both casters would have dropped pretty much equally. Just pulling in the left camber alone would only give it around .20-.30 change in caster. Yes i realize the caster didnt change on the right side and sometimes you see weird stuff like this. In a perfect world where you and all your engineering numbers work all the time unicorns poop rainbows and global warming means it shouldnt be 15* in texas but it was last weekend (shut the whole state down - really sad). My thoughts are it's something to do with the weight of the vehicle shifting or the way the alignment machine gets it's readings does this sometimes. Im not disagreeing with the original alignment being good. sure it is very neutral, in a perfect world this is what you want. Im not trying to challenge you or your engineering degree. I have no doubt you are smarter and more knowledgeable than me. The difference is I personally do alignments almost daily. I wish for the life of me i knew why the 221 s-class's need over 2* of pull sometimes even more to get them to drive straight it makes no sense. The s-class is a mystical beast. You calibrate the ride height and it changes to whatever it feels like. say you pull the left camber in, let the suspension raise and lower (airmatic car) do the sweep. for some reason the left camber stays the same and now the right camber just went more negative? Theres alot i cant explain and im not going to sit here and lie to you about it, what i can tell you is i can make a car drive the way it's supposed to. Like i said im not trying to have a pissing match. I just wanted to help this guy out and try to explain why and how it was done.

Ingenieur

it's a good thing that people who build aircraft and nuke reactors don't rely on unicorns, rainbows and subjective 'feeling', but rather on engineering/math/physics, that kind of mumbo-jumbo...

again
why wouldn't they adjust castor to the middle of spec, then dial in a bit of offset on one side to compensate for road crown if that was the whole point of the excercise? but they left both sides out of spec...because these bolts are meant to adjust for a distorted geometry due to a collision...

taking into consideration that now he has a 'clunk' in the front end and the accuracy of his original alignment I would not have touched anything
hindsight is 20:20 but in this case rings true

for all we know the 'pull' could have been due to tire pressure delta or a fat chick