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[minifreek]

I have the poly mounts on the front wishbones and the poly front ARB too, I didnt know there was any for the rears...?

What experimental types are available and where from...?

[chrisgixer]

They could challenge the structural integrity of the arms, as they are a solid lump of poly.

[05omegav6]

They could challenge the structural integrity of the arms, as they are a solid lump of poly.

This depends entirely on  how the arms are made... some are suitable, some are not. It's all in the welding around the rear bush mounting

As to the original question, the feel of the steering is different with zero toe, but that could be down to the poly bushes certainly no evidence of tyre wear oddness on mine...

Cornering speeds might have summat to do with that though... there are some very fast corners between the M4 and yours, but the inner edges should be wearing at the same rate unless the extra wear on the outside edge is a combined effect of toe and lowering...

[chrisgixer]

Anyway this toe setting....


Was hoping Tony at Wim would pop in as well.

[05omegav6]

You've driven a car with zero toe...

[Kevin Wood]

What are you expecting to see?

My take is that, as soon as you start to turn the steering wheel, ackermann geometry will cause a huge departure from any toe setting you make while static, so the static toe setting at the straight ahead position is really there to stop the car transitioning between slight toe in and slight toe out as forces deflect the suspension bushes when driving straight IMHO.

In other words, it's for directional stability.

You can wind on a degree of toe-in and the car will feel no different in the corners at all. Ditto toe-out. Toe-out on such a relatively large scale will give you crisper turn-in at the expense of it becoming a bit choppy in the straight ahead position, but you'd only consider that for a car that spends most of its' time in corners due to the tyre wear penalty you'd otherwise encounter.

So, 10 or 20 minutes one way or the other is not worth losing sleep over. Set it to a smidge of toe-in and stop worrying about it. 

[chrisgixer]

Sorry Kev, it's my tyre wear, and the life of the tyre is shortened as a result.

More over, if members are looking at poly that requires a different set up, then the base setup should be adjusted to suit. While it may not equal zero toe, i suspect front poly may need somewhere between the oe setting and zero toe.

I don't think its unreasonable to ask!

[05omegav6]

What camber are you running? Is there any scope for bringing the top of the wheels in a mm, just to lift the outer edge of the tyre and even the wear out

Does WIMs setting allow for ride height?

[wheels-inmotion]

Polly's and rose joints historically run zero toe regardless of drive. Nevertheless the toe tendency needs to be witnessed during the camber curve and that tendency will differ between suspension modifications and general compliance. 

Ackermann has nothing to do with toe.... Ackermann is the geometric steering radii differential during yaw whereas toe is the longitudinal position measured static, calculated for a dynamic condition.

Ackermann/ toe has nothing to do with lock angles. The lock angle will support Ackermann disparity which is assumed globally at 1 degree 30' measured on a 20 degree lock. Agreed if the lock angle was increased the Ackermann would/ could hold the lock position but this event would be very unusual.

Point to note and this may come as a surprise all geometric settings suggested by the manufacture are nothing more than that "suggestions". There is no absolute law the suggestions will work for everyone? Chris has issues with tyre wear so the complaint and live geometric measurements need to be correlated in order to evolve totally new positions.   

[chrisgixer]

What camber are you running? Is there any scope for bringing the top of the wheels in a mm, just to lift the outer edge of the tyre and even the wear out

Does WIMs setting allow for ride height?

I know it's a longtime ago now ....but post 1 says -1.15. 0.05 MORE than the recommended 1.10. I don't think its a camber issue, and don't want to run more camber. Or that's my current thinking anyway.

1) I read somewhere that a wider FRONT tyre will inevitable round off more due to the dynamics of McPherson strut suspension. Omega naturally rounds the fronts anyway (and flattens the rears in the middle.) Make the fronts wider and that element will only get worse.

2) But add in camber I'd expect to see the inner shoulder wear more.

3) the wear is different on the outer edge than the inner which is flattened due to camber, outer being scrubbed(for want if a better description)

4) apologies I should of mentioned this earlier, but there is what I'd call excessive tyre squeal under hard cornering. Long before it looses grip, although under steer arrives before over steer due to the wider rears. Although I expect a lower profile tyre to sqeal more and earlier anyway.

5) it's just a tweak of a non standard set up, no biggy. Cirtainly not worth all those gay groomer posts from Esta

[Webby the Bear]

This is an interesting one i'm watching closely to see an outcome of.

My camber on the front is ''in the green'' but quite close to being out of tolerance. And because of this i should see tyre edge wear.... but i'm not seeing any at all.

The only thing i can attribute this too is that i dont drive that fast, only booting it occasionally. If you, or WIM are interested I can re-post my last alignment specs (done by a Northampton co.)

[chrisgixer]

Should add, I have recently replaced a worn steering idler. Which obviously won't help.

Tony, thanks for reply. I'll add a pic of tyre wear ASAP

[05omegav6]

For comparison purposes I'll take pics of my front treads when I get home...

I wonder then from what you describe if it's not simply a side effect of cornering speed

[chrisgixer]

This is an interesting one i'm watching closely to see an outcome of.

My camber on the front is ''in the green'' but quite close to being out of tolerance. And because of this i should see tyre edge wear.... but i'm not seeing any at all.

The only thing i can attribute this too is that i dont drive that fast, only booting it occasionally. If you, or WIM are interested I can re-post my last alignment specs (done by a Northampton co.)

Narrower tyres, sedate driving, not Elite suspension, all help to keep tyre edge wear at bay.

Cornering faster/harder compresses the outside suspension, the radius of the wishbone pivot points affects the camber angle if the shock and hence the wheel, so depending on ride height (and hence wish bone angle) you'll likely see increased camber in corners. Which is what you want.

However the inside suspension extends with harder cornering, and soft suspension which increases body roll, so the wishbone pivots down and pulls the shock inboard and I increases camber when you DONT want it.

Hence, sport suspension needs to be firmer. Keeps the body flatter, less roll, more accurate camber to the road so less tyre wear and better grip.

(Ignoring roll bars btw)

[Webby the Bear]

So basically because I take corners at ''christian motoring'' speeds and i've got soft suspension (non-Elite) thats why i'm not seeing the wear? (and just for info purposes i've done around 2k miles since the alignment check)