Going in for camber adjustment tomorrow

S

stuartinzg

Active member
Going in for camber adjustment tomorrow, we will try a reduction in camber to the min possible on current suspension components, I think that's around -1.9c on the back and -0.1c on the front - will also check the tyre pressures and have a play over the weekend with the differences and will report back. :thumbsup:
 
Not noticed any neg camber induced issues on the front of my Z4, nice flat & even wear across the tyre. The thing I notice is inside edge wear on the rear tyres.
 
techathy said:
Not noticed any neg camber induced issues on the front of my Z4, nice flat & even wear across the tyre. The thing I notice is inside edge wear on the rear tyres.
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I do have the option for leaving the front, but I wasn't sure if it was a good idea to adjust one without the other. They have a lot more experience than me, so I'll ask for their feedback
 
Doing just the rear is the safe option as at worst you'll induce understeer with the levels of rear grip overpowering the front of the car.
 
techathy said:
Doing just the rear is the safe option as at worst you'll induce understeer with the levels of rear grip overpowering the front of the car.
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Extra understeer ... :tumbleweed:

But joking aside, better than snap-oversteer!

Will see what they recommend-shame I'm not currently close enough to a Z4 racing team in Germany who also offer suspension set ups (need to go through my bookmarks to find them again).
Considering a detour there on the way back from the UK in the summer after the LSD is fitted.

I think they are about the best place to go to get your Z4 handling sorted.
 
Yeah while understeer is boring it's safe. I'd prefer to dial out understeer than dial out oversteer on a 35iS.

I need to get my head around the Z4 suspension geometry some time but with my car less than 1 year old I'm gonna wait at least another year before starting with the mechanical side of things in a serious way. I'll tweak the aesthetics - splitter, skirts, getting rid of that nasty matte silver & possibly a moderate drop on Eibach springs.
 
Here is the results. He can't go lower at the rear without new camber arms. Front isn't adjustable at all. May consider adjustable all-round at some point. Considering it was only recently adjusted at BMW the before is pretty bad. No wonder it was wandering.

Left is guide, middle before, right after

IMG_20160205_101851.jpg
 
I was looking at the front of mine this morning. I think any inside edge wear on the front is down to caster angle induced camber at low speeds rather than static camber issues.

Given that sheet I've simply asked them to get the suspension dead centre on BMWs spec. That's where my car is & it feels great.
 
techathy said:
I was looking at the front of mine this morning. I think any inside edge wear on the front is down to caster angle induced camber at low speeds rather than static camber issues.

Given that sheet I've simply asked them to get the suspension dead centre on BMWs spec. That's where my car is & it feels great.
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I doubt the inner edge wear is due to camber, almost certainly due to out of spec toe.
 
The Z4 is heavy on the inside edges of its rear tyres, mine is also showing faster wear on the inside of it's front but not that much. My car was dead centre on BMWs specs & I can't see any reason this would change in the 5.5k miles its covered since then as the wear pattern I'm a seeing has stayed the same. But in stuartinzg's case yes, toe could well be causing a few issues hence why I've simply had that car zeroed to factory specs.
 
Curious. I'm on my second 35is on 19" rims. Never had any 'wandering' problems or had the suspension geometry checked/corrected on either and both have worn their tyres completely evenly front and back. As I've said in other threads/posts I was never impressed with the grip on the RE050 RFTs on the first car but grip has been a lot, lot better on the same RE050 RFTs on the second. Lack of grip down to tyre or camber? Certainly not due to incorrect toe and camber was never visibly 'out'.
 
Mine was a bit of a handful until I had it zeroed. In my case it wasn't outside tolerances but had a lob-sided setup so would want to turn ever so slightly, it meant I was fighting the car on the straighter high speed roads all the time. I never really had a grip problem with mine except for the whole RFT issue. Once I had the car corrected to factory centre it gained better motorway manners & developed this epic stability & traction driving out of corners. Stuartinzg's car is a far more extreme version of mine so can imagine he might have traction issues as it was well out of square.

There are two versions of the RE050; the originals and the RE050 A. The latter has revised carcass & tyre compound but completely interchangeable with the original so was a silent upgrade. Also remember that with stuartinzg running MPSS you've got an extra factor into the grip equation - dual compound tyres so get the best grip out of the tyres you need to ram the outside shoulder into the road. With the Z4 running rather high neg camber at the rear it may not engage the outside shoulder with the road until you get into big cornering forces so you're unable to transfer that grip into straight line traction.
 
techathy said:
With the Z4 running rather high neg camber at the rear it may not engage the outside shoulder with the road until you get into big cornering forces so you're unable to transfer that grip into straight line traction.
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This is a problem, I just can't get full throttle traction in 1st/2nd, even in dry and 14c. The thing is constantly wheel spinning.

Not sure if I should now get rear camber adjustment arms so I can go down to -1.5c/-1.2c/-1.0c, so I can test. The guys in the shop have invited me down to a track day soon, I won't be driving the car on the track (insurance), but there are roads up to the track which is almost like a mini track in itself. They have offered to test different cambers and then take temperatures on the inner/outer part of the tyre and see where I'm getting most grip.

I also need to try some different tyre pressures on this new camber set up, I think it's running too high. Will try at the RFT pressures, then keep reducing it until I see what works best. But for absolute certainty I need to use this heat tester on the tyre.
 
stuartinzg said:
techathy said:
With the Z4 running rather high neg camber at the rear it may not engage the outside shoulder with the road until you get into big cornering forces so you're unable to transfer that grip into straight line traction.
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This is a problem, I just can't get full throttle traction in 1st/2nd, even in dry and 14c. The thing is constantly wheel spinning..
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Sounds like my first 2011 35is whereas the current 2014 version is much, much better. Of course it can still leave a trail of rubber behind but once moving it is much better behaved and gets the power down quite nicely only lighting up the dash on undulations/bad surfaces under full bore acceleration. It also tolerates getting on the gas earlier exiting corners/roundabouts - the previous car would wag its tail far too easily and at temperatures below about 7C it required enormous 'respect'. I wonder if BMW made some suspension changes between the two?
 
Garvin said:
stuartinzg said:
techathy said:
With the Z4 running rather high neg camber at the rear it may not engage the outside shoulder with the road until you get into big cornering forces so you're unable to transfer that grip into straight line traction.
Click to expand...

This is a problem, I just can't get full throttle traction in 1st/2nd, even in dry and 14c. The thing is constantly wheel spinning..
Click to expand...

Sounds like my first 2011 35is whereas the current 2014 version is much, much better. Of course it can still leave a trail of rubber behind but once moving it is much better behaved and gets the power down quite nicely only lighting up the dash on undulations/bad surfaces under full bore acceleration. It also tolerates getting on the gas earlier exiting corners/roundabouts - the previous car would wag its tail far too easily and at temperatures below about 7C it required enormous 'respect'. I wonder if BMW made some suspension changes between the two?
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From what I can see, nothing on real OEM ... probably adjusted the suspension itself? I will keep digging.
 
With a fairly aggressive setup at the rear being off will have wide ranging impacts. Are you still having the same issues post-alignment?
 
techathy said:
With a fairly aggressive setup at the rear being off will have wide ranging impacts. Are you still having the same issues post-alignment?
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Check my other post just now (data log), that was a third gear pull. Even with my new camber set up it was moving around at the back and didn't feel very settled. No DSC flashes. I can't work out if it's because of the tyres (perhaps wrong for this suspension set up), or the roads here (which are very different to the UK, much less grip, designed for high temps 40c+).

I notice the tarmac in the UK is seriously grippy whenever I come back (and noisy).

Could also be that?

Did you check the RFT variation between your '11 and '14? They had 2 upgrades in that time, apparently made a huge difference. Could also be you have newer suspension rubbers and maybe mine are now needing to be replaced (I'm told around 6 years for the optimum life of the rubber). Although when I was under the car when it was on the lift, I was having a poke around and we didn't feel any obvious play in the suspension arms/track rods/etc.
 
hen maybe you do need to dial out a bit of neg camber, I was looking at BRZ with MPSS and they were running down at neg 1.5-2 deg for best track day & fast road grip.
 
techathy said:
hen maybe you do need to dial out a bit of neg camber, I was looking at BRZ with MPSS and they were running down at neg 1.5-2 deg for best track day & fast road grip.
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Yep I read the same thing online. They had better grip coming out of corners than in a straight line! (before the camber reduction)
 
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