Print

Please login or register.
1 Hour 1 Day 1 Week 1 Month Forever
Login with username, password and session length

[chrisgixer]

Yeah see, those settings are terrible. Based on the vx tollerances that are so wide as to be utterly useless.

Do yourself a favour Terry. Get it set up correctly. (Or at least get one set up correctly and measure that car and transfer those settings to the others)

And have a search, this subject has been done to death over the years. All the info is on here somewhere.

[aaronjb]

Terry, negative camber means the wheel leans in at the top.

The last cars with positive camber probably had wooden cart wheels..

[05omegav6]

Once the hub to strut bolts are tightened, the camber is set. It doesn't vary whether the suspension is loaded or not. What changes is the datum from which you measure everything...

I could build a jig to allow me to set the camber upside down on a table, as the camber angle is simply the differential between the hub face and the line from the ball joint through the centre of the shock. Haynes dimensions are wrong as they are based on Vauxhalls settings for a brand new car and allow nothing for wear and tear to any components or the overall structure of the car and also the ever variable dimensions of any replacement components.

If you set the camber as it suggests you will encounter some interesting inner edge tyre wear

Ideal is 1°10, with castor of around 5° and toe in of 0°05 at the front. (Castor might vary from side to side slightly, and only shifting the subframe can sort it, all the other dimensions must be symetrical though)

Rears will fall where you can get them, but target for 1°30 camber and toe as close to 0°05 as you can get it. Whatever the rear ends up at, the thrust angle MUST be 0°.

[05omegav6]

Incidentally, the final set up of the factory cars was done by the dealer as part of the PDI

[Nick W]

Negative camber means that the top of the wheel leans in.
The stated figure is quite a large amount for camber.
The tolerance of plus/minus 45minutes is enormous, and should be regarded with scepticism.

[tidla]

And havin a laff negative camber

[chrisgixer]

Once the hub to strut bolts are tightened, the camber is set. It doesn't vary whether the suspension is loaded or not. What changes is the datum from which you measure everything...

I could build a jig to allow me to set the camber upside down on a table, as the camber angle is simply the differential between the hub face and the line from the ball joint through the centre of the shock. Haynes dimensions are wrong as they are based on Vauxhalls settings for a brand new car and allow nothing for wear and tear to any components or the overall structure of the car and also the ever variable dimensions of any replacement components.

If you set the camber as it suggests you will encounter some interesting inner edge tyre wear

Ideal is 1°10, with castor of around 5° and toe in of 0°05 at the front. (Castor might vary from side to side slightly, and only shifting the subframe can sort it, all the other dimensions must be symetrical though)

Rears will fall where you can get them, but target for 1°30 camber and toe as close to 0°05 as you can get it. Whatever the rear ends up at, the thrust angle MUST be 0°.

Camber is indeed fixed in relation to the shock, and this is set and immoveable, ignoring flex and tyre deflection. However that measurememt alone is not important. The important bit is the camber setting in relation to the road.

When camber is said to vary, this is in relation to suspension travel. The wishbone works on a radius, and as such must pull the stub axle assembly inboard and outboard as the suspension ruses and falls.

Therfor camber, in relation to the road, does vary. This is why sport suspension is preferred over Elite suspension for enthusiastic drivers. As the tyres stay in contact with the road better, and wear  more evenly.

Prety sure that's what Terry meant by camber variation. Or camber deflection, as I call it, rightly or wrongly. The limits of McPherson strut suspension are revealed. Sadly. It needs at least another pivot somewhere, to keep the contact patch flatter, and run less camber generally.

[05omegav6]

Once the hub to strut bolts are tightened, the camber is set. It doesn't vary whether the suspension is loaded or not. What changes is the datum from which you measure everything...

I could build a jig to allow me to set the camber upside down on a table, as the camber angle is simply the differential between the hub face and the line from the ball joint through the centre of the shock. Haynes dimensions are wrong as they are based on Vauxhalls settings for a brand new car and allow nothing for wear and tear to any components or the overall structure of the car and also the ever variable dimensions of any replacement components.

If you set the camber as it suggests you will encounter some interesting inner edge tyre wear

Ideal is 1°10, with castor of around 5° and toe in of 0°05 at the front. (Castor might vary from side to side slightly, and only shifting the subframe can sort it, all the other dimensions must be symetrical though)

Rears will fall where you can get them, but target for 1°30 camber and toe as close to 0°05 as you can get it. Whatever the rear ends up at, the thrust angle MUST be 0°.

Camber is indeed fixed in relation to the shock, and this is set and immoveable, ignoring flex and tyre deflection. However that measurememt alone is not important. The important bit is the camber setting in relation to the road.

When camber is said to vary, this is in relation to suspension travel. The wishbone works on a radius, and as such must pull the stub axle assembly inboard and outboard as the suspension ruses and falls.

Therfor camber, in relation to the road, does vary. This is why sport suspension is preferred over Elite suspension for enthusiastic drivers. As the tyres stay in contact with the road better, and wear  more evenly.

Prety sure that's what Terry meant by camber variation. Or camber deflection, as I call it, rightly or wrongly. The limits of McPherson strut suspension are revealed. Sadly. It needs at least another pivot somewhere, to keep the contact patch flatter, and run less camber generally.

This should be a single, repeatable measurement for any given spring length from the factory, hence the VX settings. But factor in ten+ years of wear and abuse and horrendous variation in aftermarket parts tolerances and we arrive at WIMs settings as detailed above

[chrisgixer]

Once the hub to strut bolts are tightened, the camber is set. It doesn't vary whether the suspension is loaded or not. What changes is the datum from which you measure everything...

I could build a jig to allow me to set the camber upside down on a table, as the camber angle is simply the differential between the hub face and the line from the ball joint through the centre of the shock. Haynes dimensions are wrong as they are based on Vauxhalls settings for a brand new car and allow nothing for wear and tear to any components or the overall structure of the car and also the ever variable dimensions of any replacement components.

If you set the camber as it suggests you will encounter some interesting inner edge tyre wear

Ideal is 1°10, with castor of around 5° and toe in of 0°05 at the front. (Castor might vary from side to side slightly, and only shifting the subframe can sort it, all the other dimensions must be symetrical though)

Rears will fall where you can get them, but target for 1°30 camber and toe as close to 0°05 as you can get it. Whatever the rear ends up at, the thrust angle MUST be 0°.

Camber is indeed fixed in relation to the shock, and this is set and immoveable, ignoring flex and tyre deflection. However that measurememt alone is not important. The important bit is the camber setting in relation to the road.

When camber is said to vary, this is in relation to suspension travel. The wishbone works on a radius, and as such must pull the stub axle assembly inboard and outboard as the suspension ruses and falls.

Therfor camber, in relation to the road, does vary. This is why sport suspension is preferred over Elite suspension for enthusiastic drivers. As the tyres stay in contact with the road better, and wear  more evenly.

Prety sure that's what Terry meant by camber variation. Or camber deflection, as I call it, rightly or wrongly. The limits of McPherson strut suspension are revealed. Sadly. It needs at least another pivot somewhere, to keep the contact patch flatter, and run less camber generally.

This should be a single, repeatable measurement for any given spring length from the factory, hence the VX settings. But factor in ten+ years of wear and abuse and horrendous variation in aftermarket parts tolerances and we arrive at WIMs settings as detailed above

Mv6 or sports suspension wim, for example, recommend -1.15.

Having presented a car with brand new everything in the suspension, I fail to see how -1.45 would be acceptable at any stage.

New, old, shagged, lowered, raised, rough road package or lowered sports chassis, at no point is 1.45 of use to anyone. Never mind the +/- 45 tollerances on top of that.

-2.30 and still in the green? I don't OPPSING think so.

That tells me there IS no "method" that opel use to set up an omega. They just give themselves tolerances to allow them to throw the car together any old how, and be done with it.

Having said that, both wim and Micheldever quite often have new vehicles in for set up, prior to delivery to the customer, so opel are not alone.

[terry paget]

Thank you all for your input. I am a wiser man.
Al, I am afraid you are wrong, as Chris observes, about camber being constant with a McPherson strut/lower wishbone front suspension. It must vary by several degrees between central position and upper and lower extremes of movement. I imagine with full tank and two 70 kilo wives in the front seats the suspension is near the middle of its travel, and set at -1 degree 40 minutes. It will vary to +1 or 2 degrees at top or bottom of travel. To avoid this variation it would need double wishbone front suspension, which would require much more maintenance and not handle much better. Many, probably most, modern cars use McPherson strut front supension. Tyres will wear on the shoulders.

[05omegav6]

The position of the hub and therefore wheel in relation the the line of the shock absorber is fixed and therefore constant when the bolts are tightened. Not debatable.

The relative camber does indeed alter with suspension travel (as does all the suspension geometry ), hence the setting be done in such a way that the camber is optimised with the car at rest on a level surface.

[tidla]

Vag group use a Four link suspension set up, (think double wishbone) but because of two ball joints top and bottom it doesn't turn like you would expect when turning the wheel at the road wheel. Yes more maintenance, but yet to see one with mad tyre wear when all is correct.

[Nick W]

Vag group use a Four link suspension set up, (think double wishbone) but because of two ball joints top and bottom it doesn't turn like you would expect when turning the wheel at the road wheel. Yes more maintenance, but yet to see one with mad tyre wear when all is correct.

But it's even less maintenance friendly than the Omega, and also has a tendency to snap the links. Which is never good!

[chrisgixer]

McPherson strut is popular with manufacturers as its cheap and relatively maintanance free. But lacks wheel control and camber deflection is excessive. Ride can be choppy and inaccurate.

Double wishbone is more accurate, more compact, but more linkages means wear and loss of set up. Ride can be a bit hard with potentially less travel.

Most of which means suitability depends on how good the roads are. obviously a better surface allows less suspension travel and a firmer set up, if required.