Differnt offset wheels or spacers change alignment???

[wun911]

I got an alignment done today with the stock 16" rims

If and when I put a spacer on say 20 mm and change to the wider 17" (also wider rubber 215) does it change the alignment specs???

If it does change it in any way what changes does it induce more negative camber or toe in etc etc???

[bruce]

Yes.

[StanTheMan]

sh*t..... really?

I thought it only widens the track

[Charlie Brown]

Thinking about this logically, moving the offset of your wheels out can’t change your toe or castor. It possibly could change the camber but only ever so slightly due to the additional lever effect on the axle making the car sit "a fraction of a fly turd" lower.
It will change the scrub radius and that has its own inherent problems with bump steer.

Have a read here:
http://www.motor.org.uk/documentlibrary ... t%2009.pdf

Increasing the wheel diameter doesn’t have any effect on your alignment settings.

[wun911]

Oh coolz thanks for the quick reply!

[bruce]

I'm trying to think here (it hurts). Where is the alignment measured? On the face of the wheel? But if you change that... I think I'm applying too much thought here.

[StanTheMan]

so then the wheel surface sticks out a little further

which would validate CB's comment about the scrub radius

[hks_kansei]

wont change the alignment (except very minor camber as mentioned above)


just do it and go for a drive, if you want you can do like below and measure it all yourself both before and after.
http://forum.jdmstyletuning.com/showthr ... post602526

[rascal]

Thinking about this logically, moving the offset of your wheels out can’t change your toe or castor.

Actually changing the offset can change your toe setting, but only if the toe setting is not zero.

ie. You adjust the tie rod out to adjust the angle of the wheel to the desired toe amount (for this highly hypothetical example, assume it moves 1 degree which gives 1mm toe out)

If the wheel offset is increased (for obviously exaggerated reasons) say 3 meters then that same 1 degree would give something like 33mm of toe out. (using 'very' rough assumption that 90 degrees would be side on so 3000/90 ~ 33mm per degree of angle)

Also if you run lots of camber (either neg or pos ) then again massively offset rims would either lower(neg) or raise(pos) the car. (Actual degrees of neg camber wouldnt change but the ride height would)

[Steampunk]

spacers?
extra weight? *tsk* *tsk* Wun.

BTW, have you gotten my resin? Pam said she's expecting them today.

[wun911]

I ask because I wore out a set of rubber on my enkei wheels in like 15,000 km which is kinda quick even with one or two track days thrown in its still kinda quick.

My hypothsis was that my enkei wheels had changed the alignemnt specs etc, and that's why they wore out so quickly. (the scientist in me)

So I put the stock wheels back on and did an alignment, while I shop for semi slicks for my enkei wheels.

Please continue to discuss.

I dont understand the the effect on toe how would it change? Is my drawing too simplistic?

/------axale------\
/--------axale--------\

Polish I should go and pick up this weekend
Pams not leaving till end of month i think??
No friggin way would I use spacers

[Charlie Brown]

If the wheel offset is increased (for obviously exaggerated reasons) say 3 meters then that same 1 degree would give something like 33mm of toe out. (using 'very' rough assumption that 90 degrees would be side on so 3000/90 ~ 33mm per degree of angle

Toe on laser style alignment machines is measured in degrees (fractions there of) therefore as the toe is related to the variation, in or out, in degrees from the centreline of the car, moving the wheel or offset out 50mm, 5 metres or 5 kilometres further from the centreline of the car wont change the relationship of the toe angle with the centreline of the car.

I can understand where your coming from if you meant "increase in wheel diameter", for example, if you have a toe alignment done on 15” rims setting up a toe (in or out) of say 1mm and then change the rim diameter to an exaggerated size of 3 metres, then the toe would be 7.9 mm on the larger rim but the angle to the centreline of the car remains unchanged.

[rascal]

Toe on laser style alignment machines is measured in degrees (fractions there of) therefore as the toe is related to the variation, in or out, in degrees from the centreline of the car, moving the wheel or offset out 50mm, 5 metres or 5 kilometres further from the centreline of the car wont change the relationship of the toe angle with the centreline of the car.

Agreed that offset wouldnt change the angle in degrees, but then I've never had any of my cars toe figures measured or quoted in degrees. Always in mm. Whether string lined, or using laser machines.