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-   -   Max'd out on Alignment Settings! (http://forum.e46fanatics.com/showthread.php?t=948061)

jako1 10-01-2012 08:03 PM

Max'd out on Alignment Settings!
 
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What conditions occur to make it so you cannot make anymore adjustments to Alignment settings? My passenger side right rear is red at -1.1 and cannot be adjusted anymore. If the Left rear is green at -1.7 that would mean the RR is about .5 degree off. What suspension piece is responsible for Camber? Would that need to be replaced in order to get adjustment abilities back?

The front right seems to be having issues as well. Both Caster and Camber is yellow 2/10 a degree on both. What suspension pieces are responsible for Camber and Caster?

Newer FCAB and RTABS. New shocks, struts, tires, OEM rims refinished alignements and road force balance performed.

I am trying to eliminate the last bit of vibration. Help if you can, driving me nuts when I hit 65 miles per hour and starts to vib.

Phillip@BMPDesign 10-02-2012 08:42 AM

Alignment won't cause your vehicle to vibrate. If you are starting to get vibrations at high speeds I would suspect either a tire imbalance or a bent wheel is the culprit. I typically get my tires balanced every 3-5k miles depending on the severity of the vibrations and it will usually clear that right up. If you can feel the vibrations in your steering wheel that would be your front wheels, if they are coming from your seat its the rears.

Vibration issues could also be caused by worn control arm or stabilizer arm bushings and worn hub bearings. If it was bushings or bearing though, you would likely feel it at lower speeds as well.

As far as alignment, Toe and Camber are adjustable with tie rods and control arms respectively. Caster is typically not going to be adjustable.

Also, there is a lot of confusion about a "roadforce balance". There is a roadforce test, which can help with "match mounting" the imperfections of the tire with the imperfections of the wheel to reduce corrective weight and help eliminate balance issues inherently since it applies a force to the tire assembly and reads the amount of force pushed back against the rolling pressure. If there is a section of tire that is harder or denser and there for springier than the rest of the tire, that can be measured. If it is severe enough, then the tire can usually be replaced with the manufacturer as defective if it is new. That requires new tires (since worn tires cannot be accurately tested, they can be tested, just not accurately for roadforce) to be mounted, inflated properly, tested, deflated and rotated on the rim for matching, then retested. Balancing is the last step, and isn't actually part of the roadforce process, its a regular spin balance. Any good computer spin balance should get your wheel assembly rolling smooth, unless you have unevenly worn tires, bent wheels, or an inconsistent tread build which seems to happen primarily with less expensive tires, but could happen to any tire.

jako1 10-02-2012 09:22 AM

Thanks Phillip. The put new Michelin super on my refinished rims. At this point I can only suspect the refinishing wasn't done right. They sure do look good though. I guess the only thing left is to see if anyone can let me borrow their front wheels for me to test out.

Phillip@BMPDesign 10-02-2012 09:55 AM

There are a lot of bent bmw wheels out there, and depending on how it was refinished or where the damage may have been at could still cause some problems at high speeds. If you haven't had it rebalanced at a reputable shop (or just a different shop from where the tires were installed) you may want to have that looked at. There are also different types of balance. A lot of shops with newer equipment are using a "smart balance" that determines the minimum amount of weight to correct a balance issue, it's not perfectly balanced but usually good enough and it saves the shop on lead weight costs. Then there is a zero balance that will call for more weight, sometimes in a counterbalance configuration, but will give a better dynamic balance (correcting up and down imbalance as well as side to side).

Also, you may want to watch the wheels spin on the balancer, to see if they are out of balance and also to see if there is any movement on the inner edge of the wheel that would indicate an out of round wheel.

TrippinBimmer 10-02-2012 10:04 AM

If running stock suspension. I would say your top hat and rear lower control is tweaked...


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