Omega Owners Forum
Chat Area => General Car Chat => Topic started by: chrisgixer on 16 March 2014, 10:52:51
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We know the oe toe setting, of -0.10 combined(-0.05 each side), is designed to account for oe bushes to avoid excess toe out under braking. Possibly going passed zero toe on the brakes into a minus figure.
What effect do Polly bushes have on the toe figures. A lot of members have Polly fronts. There are also some experimental rearward bushes on some members cars.
Mine has front Poly fitted, and oe rubber gm rearward bushes, but still has a standard toe setting.
Reason for asking is, camber is set to -1.15. (0.05 more amber than the standard -1.10) yet I'm still getting more outside edge shoulder wear than on the inner edge.
Is the toe causing it/will a lesser toe setting help?....and if so how much toe to dial in given a full set of poly bushes gives a recommended toe setting of zero toe?
:)
Front tyres are 245 40 18.
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Don't know mate. ;D
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Don't know mate. ;D
Genious ::) ;D
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Don't know mate. ;D
Genious ::) ;D
At least I can spell the word. ;D
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Don't know mate. ;D
Genious ::) ;D
At least I can spell the word. ;D
Bovered?
Opps off back to gen chat.
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Don't know mate. ;D
Genious ::) ;D
At least I can spell the word. ;D
Bovered?
Opps off back to gen chat.
No. I'm stalking you.....again.
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NUUUURSE, HE'S OUT OF GEN CHAT AGAIN.
...or are they all out on strike? Take your meds Esta. Quick.
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Is the Polly front part of the Parrot system? If so I would give it my toe end.
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NUUUURSE, HE'S OUT OF GEN CHAT AGAIN.
...or are they all out on strike? Take your meds Esta. Quick.
I've had my Viagra this morning, thank you. :-*
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Is the Polly front part of the Parrot system? If so I would give it my toe end.
Don't you start. He'll cry and leave. ;D
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Is the Polly front part of the Parrot system? If so I would give it my toe end.
Don't you start. He'll cry and leave. ;D
Post count is getting a bit high...
....isn't it Esta. 593 ? ;D
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Is the Polly front part of the Parrot system? If so I would give it my toe end.
Don't you start. He'll cry and leave. ;D
Post count is getting a bit high...
....isn't it Esta. 593 ? ;D
So, what are you saying? One of us has a life? ;D
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Is the Polly front part of the Parrot system? If so I would give it my toe end.
Don't you start. He'll cry and leave. ;D
Post count is getting a bit high...
....isn't it Esta. 593 ? ;D
So, what are you saying? One of us has a life? ;D
Several lives in your case, remember the pictures. :o
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Is the Polly front part of the Parrot system? If so I would give it my toe end.
Don't you start. He'll cry and leave. ;D
Post count is getting a bit high...
....isn't it Esta. 593 ? ;D
So, what are you saying? One of us has a life? ;D
Several lives in your case, remember the pictures. :o
You've hijacked your own thread, stupid. ;D
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There was a time when admin would put you over their knee.
...ah, I see ! ;D
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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...?
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They could challenge the structural integrity of the arms, as they are a solid lump of poly.
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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...
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Anyway this toe setting.... ::) ;D
Was hoping Tony at Wim would pop in as well.
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You've driven a car with zero toe... ::)
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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. :y
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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!
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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?
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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.
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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 ;D ....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 ;D
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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.)
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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 :y
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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 :-\
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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)
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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)
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How many miles on the tyres?
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About 5k miles ago :)
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I wonder then from what you describe if it's not simply a side effect of cornering speed :-\
Having followed Chris to his house after the curry I can confirm that he does like to corner rather quickly indeed.. I only caught up as I was in the M3 - poor Kev in the MX5 disappeared into the distance behind us.. ;D
Hooligans, these Omega owners.
Out of interest, Chris, what pressure do you run the fronts at? Just wondering if the tyre is 'rolling over' under hard cornering - although you'd have to be driving like you were on Saturday an awful lot of the time for that to be the cause..
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You noticed that too ;D
Does rather like his tyres soft as well...
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poor Kev in the MX5 disappeared into the distance behind us.. ;D
<cough!> Ok, I was in the MX-5, I'll grant you that, but, after 4 Cobras... ::)
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poor Kev in the MX5 disappeared into the distance behind us.. ;D
<cough!> Ok, I was in the MX-5, I'll grant you that, but, after 4 Cobras... ::)
;D Apologies Kevin, I'll let you off for falling behind, then ;)
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poor Kev in the MX5 disappeared into the distance behind us.. ;D
<cough!> Ok, I was in the MX-5, I'll grant you that, but, after 4 Cobras... ::)
;D Apologies Kevin, I'll let you off for falling behind, then ;)
;D just you wait until Mrs Kw reads this...
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About 5k miles ago :)
Shouldn't show yet. If the settings are in range then the wear will be within the life of the tyre. If there was wear after 5k that would be bad.
But if your concerned get them to sort it. ;)
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I have run these at 28 psi. Same wear. Nice compliant ride.
Current set are at 34psi. Carrying some load and the roads are buggered.
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You noticed that too ;D
Does rather like his tyres soft as well...
32psi standard Al. Nobody runs max load pressures all the time. Ride is way too harsh.
....unless your a Taxi driver. ::) no wonder they pootle about everywhere
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;D not known for pootling anywhere, me ::)
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Zero interest. ;D
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poor Kev in the MX5 disappeared into the distance behind us.. ;D
<cough!> Ok, I was in the MX-5, I'll grant you that, but, after 4 Cobras... ::)
It's ok, we got out and pushed waited at the last too roundabouts so our Kev could catch up. Bless him. ;) ;D
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Zero interest. ;D
Opps off you ;D
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About 5k miles ago :)
Shouldn't show yet. If the settings are in range then the wear will be within the life of the tyre. If there was wear after 5k that would be bad.
But if your concerned get them to sort it. ;)
Thanks Chris.
on the contrary i'm not concerned at all. No wear equals no problem in my mind :)
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Or solid ditchfinders ;D
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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.
That about sums it up. Squeal is obviously excessive slip, which equals wear.
Given your wide rears, the car will understeer - all Omegas do, even with standard tyres sizes - which will aggrevate it further, particularly coming out of the corners.
Due to working in MK, I scrub out the outside shoulder of the NSF all the time, as most of the loading goes to that wheel around roundabouts.
If you drive that hard, you probably need more aggressive camber, possibly approaching the Irmscher recommendation (maybe not quite that much). But when I ran 1'30, I found straight line stability awful (although that particular car has never had good straight line stability).
Somewhere, I fear there has to be a compromise if you want soft tyres and drive them hard, yet still want durability.
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There's a video on you tube, by top gear Australia, showing the new vxr8 on 20" inch low profile wheels and tyres. It's an option available over the standard 19" wheels.
The tyre squeal is much more pronounced on the larger size. You said yourself they give a good audible warning before letting go.
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So the squeal could be understeer. It could be excess toe/helped by less toe. It could be wheel size/lower profile tyres.
But obviously squeal isn't good.
In a long sweeper, as described to TB, if it stats to squeal, boot it and the squeal goes, I guess as the front is unloaded...?
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It could be excess toe/helped by less toe.
I doubt any toe setting that's valid would affect the amount of squeal when cornering