Alignment done w/ Spacers on=Out of alignment w/ Spacers off?

[Exclusivs]

Most recent alignment was done with spacers on the car. Now spacers are off, do I need a new alignment? I can post last alignment specs if needed

[jadnashuanh]

Spacers make the lever arms of the independent axle longer, which will (probably) change the alignment. I do not know if it will be enough to make a noticeable difference, but it will be different.

[LarThaL]

Spacers will not change the alignment specs as all the suspension components will still retain their basic geometric relationships with each other.

[W Cole]

Originally Posted by jadnashuanh

Spacers make the lever arms of the independent axle longer, which will (probably) change the alignment. I do not know if it will be enough to make a noticeable difference, but it will be different.

Never thought about this. If I am thinking about it correctly the spacers will effectively lengthen the lower control arms which will mean more leverage against the springs and effectively lower the spring rate so the car will sit slightly lower.

I think you would have to have some very precise equipment to measure this affect though. I wouldn't worry about it.

[jadnashuanh]

Well, it may not make any difference at all. Spacers are used so that aftermarket wheels can be mounted that might not normally sit properly on the hub. So, it might not actually make the lever longer, but it could! Or, shorter.

[Exclusivs]

Spacers were installed on the car, and alignment done right after - not because of spacers but I had also adjusted height of the KWV3 suspension.

If the car was to go back on the alignment rack now w/o the spacers - would it read same alignment specs that were done w/ the spacers?

The reason I bring this up, is to see if it is possible to dial out some of the negative camber that was done to fit aggressively spaced wheels.

[kenwelch]

Originally Posted by Exclusivs

Spacers were installed on the car, and alignment done right after - not because of spacers but I had also adjusted height of the KWV3 suspension.

If the car was to go back on the alignment rack now w/o the spacers - would it read same alignment specs that were done w/ the spacers?

The reason I bring this up, is to see if it is possible to dial out some of the negative camber that was done to fit aggressively spaced wheels.

When you “dial out” the negative camber, that adjustment will also change the toe setting because you are moving the top of the strut outward. The car will need to go back on the alignment equipment for correction back to specification.

Removing the spacers will not change the adjustable angles measured with modern four-wheel alignment equipment. Removing the spacers will return the alignment geometry back to the correct “scrub radius”. The BMW engineers designed the suspension and wheel offset for the best scrub radius resulting in better steering feel and to minimize tire wear. The alignment equipment does not measure scrub radius and there is not a published specification or setting.
See scrub radius:
http://en.wikipedia.org/wiki/Scrub_radius

http://www.hrsprings.com/technical/scrub_radius

Video:
http://www.dailymotion.com/video/xyr...ub-radius_auto

[Exclusivs]

Originally Posted by kenwelch

When you “dial out” the negative camber, that adjustment will also change the toe setting because you are moving the top of the strut outward. The car will need to go back on the alignment equipment for correction back to specification.

Removing the spacers will not change the adjustable angles measured with modern four-wheel alignment equipment. Removing the spacers will return the alignment geometry back to the correct “scrub radius”. The BMW engineers designed the suspension and wheel offset for the best scrub radius resulting in better steering feel and to minimize tire wear. The alignment equipment does not measure scrub radius and there is not a published specification or setting.
See scrub radius:
http://en.wikipedia.org/wiki/Scrub_radius

http://www.hrsprings.com/technical/scrub_radius

Video:
http://www.dailymotion.com/video/xyr...ub-radius_auto

By "Dial out" I meant yes, on the alignment machine. I am not running camber plates so only way to adjust camber is on the rack. Doesn't seem possible that not even camber is effected

[TXmtrhed]

[QUOTE=Exclusivs;15460444]

If the car was to go back on the alignment rack now w/o the spacers - would it read same alignment specs that were done w/ the spacers?

QUOTE]

Slightly OT but IME if you took the car back to the alignment shop with no changes you could get slightly different readings. Readings are highly dependant on the user setup and machines vary from one to another. So even though there might actually be a change in ride height (and camber and toe) you might be hard pressed to define it.

But if you're going to try and dial out the negative camber you had with the spaced wheels you will of course have to do it on the rack (to get it close).

[kenwelch]

Originally Posted by Exclusivs

Doesn't seem possible that not even camber is effected

The wheel spacers do not change the camber angle. The spacers just move the wheel further out on the angle the spindle (axle) is pointed. If the spindle angle stays the same then the camber angle stays the same.

Will the alignment be different after removing the spacers?
Not if comparing the before measurements (with the spacers) then comparing the readings without the spacers on the same equipment, same day, same ride height, with the same technician. Change any of these and you might get a difference.

[Exclusivs]

Originally Posted by kenwelch

The wheel spacers do not change the camber angle. The spacers just move the wheel further out on the angle the spindle (axle) is pointed. If the spindle angle stays the same then the camber angle stays the same.

Will the alignment be different after removing the spacers?
Not if comparing the before measurements (with the spacers) then comparing the readings without the spacers on the same equipment, same day, same ride height, with the same technician. Change any of these and you might get a difference.

Got it. Thanks for confirming that

Is it safe to conclude that spacers have no impact on the adjustable areas of alignment?

[rocket_science]

I've never had it impact the alignment. Pivot points are still the same. It just emphasizes anything not aligned properly.