More front negative camber. Who's done it and how?

[Spaniarduk]

Instead or resurrecting the following thread,
https://z4-forum.com/forum/viewtopic.php?t=27925
I thought I'd start a new one by asking:
Who here have done it?
How? Other alternatives?
How much more neg. camber gained?

I have already removed the top strut alignment pins, with good results, but I still feel the car feels a little clumsy and understeers too much for my liking when pushing round tight corners. I am now considering adding 2 x 1.2mm washers at the 2 clamping points of the 3 bolts that attach the bottom of the strut to the hub in the front axel. A quick rough calculation says that doing that would give be about -0.7⁰ of camber either side.

Yes! I know - i would need to get my tracking done to account for this shenanigans lol

What's your experience?

Thanks in advanced

 

[TomK]

You've put this in the wrong section really as the front strut design is quite different between an M and the non M.
The only way to get more negative camber with a non M strut is to rotate it through 180deg, assuming you don't want to buy camber plates.
With the M's strut you can add the shims to get the camber you require as you suggest, or buy camber plates.

 

[Spaniarduk]

[ref]TomK[/ref], thanks for the comment. I assumed the front suspension was very much the same for M and non-M apart from the offset lollipops and the arb thickness! Are the struts and hubs fundamentally different between both, then??

 

[MrPT]

Can you get a cheeky free alignment somewhere to just see where you are now?

Will defer to others who have experimented a bit more, but in my opinion there is easily enough front neg available for road use, especially with the pins pulled. Sort the rear out first (CSL specs are good, maybe with a bit more toe) and then figure out what you want to do with the front.

If it feels “clumsy” now it will only get worse if you end up trying to force the car to rotate with an overly aggressive front axle (plus it will tramline, may wear your tyres unevenly etc). The rear is pretty pinned down unless you give it a boot full or “back it in”.

 

[Spaniarduk]

[ref]MrPT[/ref], as much as I like tinkering and trying new things in my car I'm gonna have to say that that's a sensible advice and you're right. Perhaps I should start by knowing exactly where I'm at and only then should i consider implementing changes. In my defense I have to say that it's just too easy to throw a couple of washers 'in there' to see what happens :evil: :rofl:
How should i start my search for a good, reputable garage in my area (Leicestershire) that can check, correct and advice on different chassis set ups? Would any BMW independent do?

 

[MrPT]

I’m sure you could get a good recommendation from the forum for somewhere near you. A specialist alignment place would be best, but you do hear of the odd hidden gem of “decent alignment machine + alignment guru” at independent or dealer garages.

You’ll probably hear a lot about “CSL geo” in researching the area. While this might not be the perfect set of alignment settings for you (it is relatively aggressive and intended for a model with a longer wheelbase) it is a known reference point that you can discuss with other people and tune to your liking.

Suspension and tyres are other options. You could go softer or wider at the front to try and reduce understeer, or stiffer and narrower at the back. Pretty stiff at the back already though, as I’m sure you’ve noticed!

 

[Spaniarduk]

Excellent pointers. Thanks again [ref]MrPT[/ref].

I will need front new tyres next year (I'll be SORN-ing my car in the next few weeks until the Spring), so worth taking what you say about tyres into account. I replaced my rear ones with Michelin ones in standard size last year. Since then ive spent some time playing with different tyre pressures. I eventually settled with 2.3 bar front and 1.9 bar rear (that's about 30psi, i think). I know the tyre pressure at the rear is much, much lower than the recommended, but i find that it gives the rear end a bit more 'movement' around corners, it makes the car a bit more communicative and definietly less crashy, and also more comfortable and with better traction over broken tarmac.

I'll start looking doing some research on different chassis set up (i have heard of the CSL, but never bothered trying to find what it actually brings with it).

Thanks again

 

[enuff_zed]

Others may correct me if I'm wrong with modern technology etc, but back in my youth, playing with Ford Capris, it was always assumed that lower pressure in the rear tyres caused more understeer and vice versa.

I am just wondering if your understeer issue is self induced?

What happens if you pump the rear tyres back up a bit? It's an easy check............... and free

 

[buzyg]

Agree with MrPT. The standard front camber on the ///M is generaly fine for road use. Changing the tyres and adjusting the pressures can also make a very noticeable difference to turn in and tramlining. If the Ballance is wrong then always consider the back first. That is where the control natrualy lies on these cars as you approach their limits. I am no expert in such matters, just my own experience from subtle tweaks over the years.

 

[Spaniarduk]

[ref]enuff_zed[/ref], I will try again with higher tyre pressures, but what I remember is that it made the rear end bouncy and less progressive. I did notice though that with really high pressure the rear end felt a bit 'floaty?’ on perfectly smooth tarmac, but also awful on anything other than that. I will try again this weekend...

 

[Spaniarduk]

[ref]buzyg[/ref], interesting. Thanks

 

[enuff_zed]

[ref]enuff_zed[/ref], I will try again with higher tyre pressures, but what I remember is that it made the rear end bouncy and less progressive. I did notice though that with really high pressure the rear end felt a bit 'floaty?’ on perfectly smooth tarmac, but also awful on anything other than that. I will try again this weekend...

So as it is the balance from front to rear, why not raise the rear pressures a bit and drop the front a bit?