Z4MC - Custom Geometry for Eibach Pro Kit

[StevenH72]

Afternoon,

I'm getting Eibachs fitted to my car on Saturday and am trying to figure out the best geometry settings for the ///M with the lower springs.

From what I've read the following seems to be the favoured set-up:

Front:
Maximum -ve camber (~2.0 deg?? via pulling camber pins)
0.00 Toe-in

Rear:
1.2 deg -ve camber
slight toe-in (0.02??)

As I understand, standard set-up is 1.5deg camber and 0.14 toe in on the front and 1.0deg camber and 0.05deg toe in at the rear (of course this is on standard suspension)

I want to eliminate some of the understeer tendencies, whilst maintaining as even tyre wear as possible. My car isn't a DD and as such doesn't see a huge amount of motorway driving, I spend most of my time cruising around A / B roads.

I've seen a few other "set-ups" that have been favoured and would like input from those running (or who have previously ran) Eibach springs as to what the 'best' geometry settings are.

Cheers.

 

[gwatson]

I have the same setup on Eibach's, but on a roadster (which has less toe as standard than the coupe).

My aim was to liven things up, a fast road setup if you like, so I looked at matching mine to the more aggressive CSL setup by neutralising the toe and increasing the camber at the rear. This resulted in a big improvement!! It turns in a lot better and the rear feels much more connected.

Front
-1.45 camber
0.00 for toe

Rear:
-1.49 camber
-0.03 for toe

 

[jamiez]

Some nice Eibachs you got there Steve - oh and the same geo setup as me - funny that

 

[StevenH72]

Some nice Eibachs you got there Steve - oh and the same geo setup as me - funny that

....great minds

Just a final check to see if anybody else has any words of wisdom.

The toe-in recommendations (none at front and slight rear) seem pretty conclusive, but there are varying reports of the ideal front and rear camber.

Although the general consensus is to increase both the front and rear camber.

It seems a big deal to pull the camber pins....want to make sure it's the right thing!

 

[RedUn]

I run CSL geo on mine, it's on the standard suspension but if I was to adjust the ride height I'd stick to similar settings as it is nice and neutral.

Sent from my HTC One using Tapatalk

 

[StevenH72]

I run CSL geo on mine, it's on the standard suspension but if I was to adjust the ride height I'd stick to similar settings as it is nice and neutral.

Sent from my HTC One using Tapatalk

Cheers RedUn.

Looks like there are two horses in this run.

CSL Set-Up
Front:
-1.45 Camber
0.00 Toe

Rear:
-1.49 Camber
-0.03 Toe

Camber Pin Pull
Front:
-2.00 Camber
0.00 Toe

Rear:
-1.2 Camber
0.02 Toe

Any suspension experts able to comment as to the consequences if either set-up?

I'm guessing that the front 1.45 camber will make for a more even wear than pulling the camber pins, but that by pulling the camber pins I'll gain more front end grip in the corners? What difference would I notice in the rear between 1.2 or 1.49 camber?

Cheers for the help guys.

 

[RedUn]

This might not answer your question its a collection of my thoughts...

In theory the camber pin geo will be prone to oversteer more than the CSL geo. It depends on your tyres and suspension setup to whether you could even make use of 2 degrees on camber on the front on the road, maybe on track. I doubt you would really notice too much difference on the rear with the camber differences, you'd probably notice the toe more. I like my cars to have as much grip as possible while staying neutral, artificially reducing grip on the rear vs the front doesn't make sense to me unless your going drifting. BMW probably knew what they were doing on the CSL so I'll be sticking with them settings unless I decide to track the car more.

Sent from my HTC One using Tapatalk

 

[Franzino]

Interesting stuff..!

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.

 

[jimmybell]

ignore - found the other thread

 

[Franzino]

ignore - found the other thread

Which one? Maybe I can find an answer on my questions there?

 

[jimmybell]

Hey Franzino - duplicate thread here: http://www.z4-forum.com/forum/viewtopic.php?f=9&t=62466

 

[StevenH72]

Hey Franzino - duplicate thread here: http://www.z4-forum.com/forum/viewtopic.php?f=9&t=62466

oi, nothing duplicated, merely a progressive thread a before and after if you will :wink:

 

[jimmybell]

Hey Franzino - duplicate thread here: http://www.z4-forum.com/forum/viewtopic.php?f=9&t=62466

oi, nothing duplicated, merely a progressive thread a before and after if you will :wink:

Hah. i think i'm going to do similar so it's good to have the documentation. How are you finding it? Much benefit beyond the aesthetics?

I think with the 19" CSL's especially the ride height looks a little too high - noticed mine a lot more at the Kent meet surrounded by others who'd been lowered.

 

[StevenH72]

yeh a big difference. No body pitch on braking/ acceleration. In the corners the turn in is much more direct and the back end feels a little bit more twitchy.

The ride seems better also, smoother.

Big improvement imo

 

[jimmybell]

Sounds good - bet you're chuffed.

My £300 allocated to this is now about to go to technosport for valve shims methinks

 

[StevenH72]

Sounds good - bet you're chuffed.

My £300 allocated to this is now about to go to technosport for valve shims methinks

Yeh I saw the valve shim thread. My engine is quite tappety (although I always thought this was pretty normal), I need to have a listen tonight and compare against yours. Let me know how it goes, I might need to get mine looked at also.