M/// understeer advice ( Sorted :)

[Yorkie Z]

Hello gents

I'm after some advice regarding getting a wheel alignment done. A few weeks ago I had quite a bit of open space to myself and decided to have some fun :evil: However I was quite surprised by the amount of understeer I was getting when my plan was oversteer. Even with the Scandinavian flick I was having problems. Now I realise the cars set up to be safe, but it's a bit too safe.

So I'm after some up to date info on more playful settings regarding alignment. From searching on here it seems the CSl settings are the way forward.

Would really appreciate your comments and experiences

Ideally I'm after the figures to take along to the garage and get them to set it up according.

My cars been lowered on eibach and running on 19's.

Thanks Chris

 

[MrPT]

As a free experiment you could try dropping the front tire pressures, relative to the rear. Also, with the stock suspension, you can probably accelerate into a corner then do a sudden "lift" to get the weight forward and just chuck the car into a turn. My friend can do something similar in his Elise using a sharp tap of the brakes, but I don't know whether that would work as well for us since there's already a lot of weight over the front wheels to make use of.

Neither are going to make a huge difference, but something to try anyway.

 

[Fishy Dave]

The key for a bit of hooning, drifting fun at relatively low speeds is weight transfer. Hard on the brakes in a straight line, then immediately turn and hard on the power and the rear will come round. As long as the car is still 'on its nose' then this should do it. As an example, the first couple of drifts in my video here https://www.youtube.com/watch?v=K6m0GyPtufM were initiated after a heavy brake, almost to standstill, this way I knew it would spin the rears rather than understeer. My Caterham only had 140 bhp and with a passenger it was very easy to just understeer in huge circles instead of drift!
For other occasions then a bit more negative front camber (parallel front toe) and a smidge of rear toe out should give you the liveliness you desire with fairly minimal extra tyre wear. For more front camber pull the pins at the top of the strut for an extra half degree (assuming you have standard front shocks) and add longer lower strut bolts with a washer to give a bit more, see page 2 of this thread: http://www.z4-forum.com/forum/viewtopic.php?f=9&t=88742&p=1312956&hilit=negative+camber#p1312956
I would aim for 1 to 2 mm of toe out at the rear and see how you find it. Running 3 to 4mm toe out made the rear of my car possibly a bit too lively, but fun :evil:

If you have a flat piece of driveway and a couple of hours then why not do the set up yourself using the 'string' method? It's what I use having previously paid for others to set the car up, then progressed onto lasers before realising the string works best for me. Enjoy!

 

[Argenta]

I second the max camber front.
Have the Eibach & 19" like you, but also pulled the pins and maxxed it. Turned out to be ca -1.75 deg front camber, with -2 deg rear std camber.
Pretty std toe-in too, 2mm rear & 1mm front.

Mines very direct and neutral, no understeer.
With the recent M-Track its a dream on track!

 

[breezer]

I've opted for 4 minutes of toe in at the front, and 6 at the rear - very nearly neutral. It's helped a bit, but remember any car will understeer under certain conditions.

 

[just-right]

Additional camber on the front should help alleviate some of the understeer. My E46 had the same tyre sizes all around but felt quite a bit more neutral. This makes me wonder if the mechanical balance is too far forward in the Z4M. I.e. the springs, anti roll bar and dampers are slightly too stiff/hard at the front relative to the rear. Does anyone have the stock specs on the sizes and rates?

 

[exdos]

This makes me wonder if the mechanical balance is too far forward in the Z4M. I.e. the springs, anti roll bar and dampers are slightly too stiff/hard at the front relative to the rear. Does anyone have the stock specs on the sizes and rates?

It's actually the opposite: the OEM front suspension is too soft and the rear is too stiff. Aftermarket suspensions corrects this imbalance. The OEM car pitches heavily on braking which promotes understeer and the static toe-in settings then increase considerably in the dynamic situation when the front end is pitched.

Understeer can be overcome with driving technique if you get the load-shifting set-up prior to turning.

 

[Yorkie Z]

Some interesting stuff here. So the CSL setting isnt so popular now.?

 

[RedUn]

I found the csl settings very good, car was very neutral

I've only gone away from them because I've gone for a more aggressive setup for track use.

 

[Fishy Dave]

Nothing wrong with the CSL settings, it will likely improve things, I was suggesting a way of encouraging a slightly more extreme set up for maximising the hooning fun.

 

[mattfwalters]

I went with 265-section rubber in the front and rear, along with an aggressive alignment. Understeer simply vanished for some reason! :evil:

 

[Yorkie Z]

Nothing wrong with the CSL settings, it will likely improve things, I was suggesting a way of encouraging a slightly more extreme set up for maximising the hooning fun.

Hooning fun sounds great Your video looked lots of fun.

Had a busy weekend so just looking through all the info now. Thanks for the advice

 

[Yorkie Z]

I seem to be find conflicting information regarding the CSL alignment figures vers ZMR. Can anyone shed any light please.?

 

[Yorkie Z]

The key for a bit of hooning, drifting fun at relatively low speeds is weight transfer. Hard on the brakes in a straight line, then immediately turn and hard on the power and the rear will come round. As long as the car is still 'on its nose' then this should do it. As an example, the first couple of drifts in my video here https://www.youtube.com/watch?v=K6m0GyPtufM were initiated after a heavy brake, almost to standstill, this way I knew it would spin the rears rather than understeer. My Caterham only had 140 bhp and with a passenger it was very easy to just understeer in huge circles instead of drift!
For other occasions then a bit more negative front camber (parallel front toe) and a smidge of rear toe out should give you the liveliness you desire with fairly minimal extra tyre wear. For more front camber pull the pins at the top of the strut for an extra half degree (assuming you have standard front shocks) and add longer lower strut bolts with a washer to give a bit more, see page 2 of this thread: http://www.z4-forum.com/forum/viewtopic.php?f=9&t=88742&p=1312956&hilit=negative+camber#p1312956
I would aim for 1 to 2 mm of toe out at the rear and see how you find it. Running 3 to 4mm toe out made the rear of my car possibly a bit too lively, but fun :evil:

If you have a flat piece of driveway and a couple of hours then why not do the set up yourself using the 'string' method? It's what I use having previously paid for others to set the car up, then progressed onto lasers before realising the string works best for me. Enjoy!

First time I've bothered with alignment settings so please forgive my stupidity

So from what you and Argenta are saying ideally I should go for.

Front Camber -1.75 deg
Front Toe 1.00mm
Rear Camber -2.0 deg
Rear Toe 2.00mm

im not confident enough to try the string method just yet. I'll let my local garage sort it, but wanted to be armed with the correct fugues.

 

[tjlazer]

I think you may struggle to hit that level of camber without plates. I would recommend more camber upfront and less at the back (1.5/1 in fact) but give it a whirl and let us know how you get on!

 

[Yorkie Z]

Well I've have the alignment done and the car feels so much better from a playful point of view. Camber pins out at the front and maxed out. I'm still considering some shims to take it to about -2.25. Will try it out for a while as it is thou.

Understeer seems to have gone and oversteer is easily accessible, which actually makes it feel safer. Why the car came with some much understeer is beyond me.

Big thanks to everyone who helped with info on here and a big thanks to Fishydave

 

[Steve84N]

What camber did you get on the front?

 

[Fishy Dave]

You're very welcome, that's three of us running a smidge of rear toe out now.