geometry alignment settings Z4M -> advice / opinions?

[Franzino]

I have a Z4M roadster with Eibach springs + AP brake kit + Strut Brace + 19" CSL wheels + Michelin Supersports…. In the dry months, my Z4M comes on track once a month..the rest of the time it's a normal street car. A Bilstein PSS-10 suspension will be a future mod, but for now I'm staying with OEM dampers and Eibach springs.

Is there a big difference between the geometry from the Z4M coupe and roadster? I never knew there was a difference in geo between the two. I know there is a difference between the steering rack and the dampers and springs.

Something controversial to add, the roadster has a slightly more aggressive geo than the coupe
Less toe in up front and less toe in at the rear, total figures are 0 deg 04 and 0 deg 22. Camber unchanged.
Very strange!

Which is the correct CSL geo…this one ?



http://www.breezemotorsport.com/csl geometry.htm

or this?

Front
-1.45 camber
0.00 for toe

Rear:
-1.49 camber
-0.03 for toe

What are the up and downs of this CSL set-up? I don't' want something to aggressive that makes the handling on the limit less predictable… I also don't want to much uneven tyre wear.

My Z4M is a daily street car, that also gets driven around 10 times a year on track (90% Nurburgring). Would this CSL geometry be something for me and my car? The CSL will probably work great on the e46 M3, but the Z4M is a different car (with the same engine and brakes).

Why copy CSL settings?
CSLs suspension and dimensions are different and most CSL guys don't use those CSL settings anyway. Best to stop just coping a CSL and do something with some thought attached.

These are the geo settings currently on my car (oem dampers with Eibach springs)


Any opinions or advice on which geometry settings to go for? Without going to extreme or making the handling to unpredictable on the limit..

Why is there a big difference between the toe on the rear left and right side?

 

[Viren]

I noticed toe made the biggest difference, currently running

Front:
Toe = 0.01 (either side)
Camber = 0.5 (unfortunately can't get anymore but hoping to shim for another degree, ideally would like 1.2-1.5)

Rear:
Toe = 0.06 either side
Camber = 1.4

Set-up has made the car more predictable, better turn in and better "feel". Although I would like some more front camber!

Cheers

 

[StevenH72]

If you reduce your rear camber, you should get a greater degree of tyre contact, which would provide more rear end grip (i.e. more traction). Maybe reducing rear camber to -1.0 deg would help.

Sort out the rear toe 0.02 on each side. The rest of it looks pretty good. Not sure you'll feel much difference by reducing the front toe further, but you could completely neutralise them (0.00ea).

Tyre wear I'd imagine will still be pretty even (no scrubbing) and the steering should be more direct, but the slight toe on the rear should stop the back becoming too lively.

 

[Franzino]

I noticed toe made the biggest difference, currently running

Front:
Toe = 0.01 (either side)
Camber = 0.5 (unfortunately can't get anymore but hoping to shim for another degree, ideally would like 1.2-1.5)

Rear:
Toe = 0.06 either side
Camber = 1.4

Set-up has made the car more predictable, better turn in and better "feel". Although I would like some more front camber!

Cheers

So my car alignment has more negative camber than yours, so it should have more grip in the corners? Turn in is indeed something that can be changed with the toe.

 

[Fast3000]

Sorry for the slight post hijack, but made sense to restart the converstation..... :roll:

I am taking my Z4M back to the dealership to have the tracking looked at....if hopefully they do give the car a full track and they provide me with the print out.....I shall be comparing on here....

Any hints or tips if I get to speak to the technician carrying out the tracking?

 

[Fast3000]

By the way.... i shall be getting a standard vanilla flavour tracking done!