Wheel alignment / adjustment

[Zedebee]

I am going to get a 4-wheel alignment done soon, but I would like to know what the chap doing it will actually do. I know there are many parameters of wheel geometry (toe, caster, camber etc) but there seems to very little adjustment you can do on a Z4, apart from wind the track rods in/out. Can anyone enlighten me?

Also, the rears on my 3.0i seem to have significantly more camber (i.e. they splay out) than my son’s 2.5i. Both are on Msport suspension the only difference is I have 107s with a 15mm spacer, he has 108s without. Any ideas why this might be?

[enuff_zed]

A spacer will make the camber look worse as you are projecting the wheel outwards from the reference point.
Resetting the camber with the spacers fitted should address that.
The RTAB mounting points can be adjusted too, affecting toe. Three bolts. Worth popping them out one at a time beforehand so you know it can all be done.
Rear camber is adjusted using eccentric bolts on the outer end of the lower arm. Again, freeing them up first, or replacing them, is worthwhile.
Front end toe is adjusted on the tie rods.
Camber is by moving the top mounts. Take out the camber pins before you go. They are only there to give a basic set up at the factory.
All info from the ex-Lotus development engineer who does mine.
He puts a paint mark on the front top mount bolts once done as a reference point.

[Zedebee]

Wow, thanks Martin. Great insight.

[B21]

I am going to get a 4-wheel alignment done soon, but I would like to know what the chap doing it will actually do. I know there are many parameters of wheel geometry (toe, caster, camber etc) but there seems to very little adjustment you can do on a Z4, apart from wind the track rods in/out. Can anyone enlighten me?

Also, the rears on my 3.0i seem to have significantly more camber (i.e. they splay out) than my son’s 2.5i. Both are on Msport suspension the only difference is I have 107s with a 15mm spacer, he has 108s without. Any ideas why this might be?

You’re correct you can’t really change castor..minor change in front camber, rear camber and toe..reason why rear camber increases is all the rear bushes wear …as they wear camber increases..assuming it’s stock ..

[Mr Tidy]

I don't know if you have somewhere in mind to get an alignment done Ben but I took mine to TWG Automotive in Camberley and it totally transformed how the car drove. (Being an M I had it done to E46 M3 CSL settings).

Will who runs it is ex-Sytner and used to race in the BMW Compact Cup series, but now races Legends on circuits (rather than ovals). I think that's primarily why he invested in the laser kit!

It's worth checking the track rod ends are free before going - mine were seized solid so he had to fit new ones both sides.

Also worth checking there are no worn bushes and deciding whether you want to keep the spacers on or not because removing them afterwards would put it out of alignment.

[Zedebee]

I am going to get a 4-wheel alignment done soon, but I would like to know what the chap doing it will actually do. I know there are many parameters of wheel geometry (toe, caster, camber etc) but there seems to very little adjustment you can do on a Z4, apart from wind the track rods in/out. Can anyone enlighten me?

Also, the rears on my 3.0i seem to have significantly more camber (i.e. they splay out) than my son’s 2.5i. Both are on Msport suspension the only difference is I have 107s with a 15mm spacer, he has 108s without. Any ideas why this might be?

You’re correct you can’t really change castor..minor change in front camber, rear camber and toe..reason why rear camber increases is all the rear bushes wear …as they wear camber increases..assuming it’s stock ..

Yes, stock. I’d be surprised if it was the bushes. I’m comparing to son’s car. I think both are on original bushes, mine is on 80k, his on 110k, but his camber looks completely neutral. Does the rear spring height/length make any difference here?

[B21]

I am going to get a 4-wheel alignment done soon, but I would like to know what the chap doing it will actually do. I know there are many parameters of wheel geometry (toe, caster, camber etc) but there seems to very little adjustment you can do on a Z4, apart from wind the track rods in/out. Can anyone enlighten me?

Also, the rears on my 3.0i seem to have significantly more camber (i.e. they splay out) than my son’s 2.5i. Both are on Msport suspension the only difference is I have 107s with a 15mm spacer, he has 108s without. Any ideas why this might be?

You’re correct you can’t really change castor..minor change in front camber, rear camber and toe..reason why rear camber increases is all the rear bushes wear …as they wear camber increases..assuming it’s stock ..

Yes, stock. I’d be surprised if it was the bushes. I’m comparing to son’s car. I think both are on original bushes, mine is on 80k, his on 110k, but his camber looks completely neutral. Does the rear spring height/length make any difference here?

Yes shorter length suspension unit on rear increases rear camber..quite a large change due to altering that variable..obviously you can adjust it out providing you have reached the limit of the camber arm adjustment..usually the rear toe in can’t be corrected if there was too much initial camber without adjustable RTAB carrier plates..