-1' 20'' is the value I target for front camber......and both as close to each other as possible.....on most Omegas this is about as little camber as the adjustment will allow you to set.....
Can i offer this reading from the wim forum... It's just a simple explanation that there is no such thing as "Actual Geometry positions"
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The simple answer is that there is no such thing!
Seeking the perfect set-up is dependent on variables that exceed even the most experienced in the industry, F1 with millions invested each season still cannot deliver 'matter of fact' positions, so what do you do? how can anyone establish the perfect set-up.
First lets look at the manufacture
Geometry within new models tends to be an extension of previous established positions, minor tweaks to accommodate suspension travel, wider tyres and so on is often visible and do fall into the 'safe zone', but attempt to manufacture a completely new Geometry then things can go very wrong, as it did for the Nissan 350Z and the new Peugeot 1002.
So now your modified
Taken from the above the car had recognized Geometric positions and is now modified... suspension, tyres, turbo but now things just don't feel right, well maybe understanding the 'forces' involved within Geometry not just the name of the angles could help.
Toe: exerts no force unless violated to the maximum since the chosen position 'Dynamically' is 0
Camber: exerts a 'conical' force and will want to roll into the lowest point of the imaginary cone, the force adds security to straight line travel and compensates for body roll.... excessive camber will make the steering heavy and lazy (turn out) due to the 'compressive' force generated from the angular position of the imaginary cone.
Castor: exerts a non-reactive longitudinal force assuming the positions over the axle are within manufactured tolerances, on cornering the Castor contributes toward displacement of the steering axis and the position of the 'scrub radius' this force is very important.
KPI/SJI: exerts a very high force toward directional stability, this force is immediately detectable if any attempt is made to deviate from straight line travel... the force is generated by 'inclining' the pin during any steering action, this inclination lifts the vehicle and adds weight on the pin, in reply the equilibrium through the rack will return the steering so the KPI can relax.
How to develop your own positions
First consider your reasons, what do you expect from the car and to what end, is tyre wear an issue, are the modifications cosmetic or deliberate? The four examples shown reflect the most common consequences of modifying a car, in particular lowering, the forces displayed need to be examined in your own example and explored.
It could be easy to assume now that all things 'Geometrical have been covered?
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Following posts in this thread can i also explain these observations...
1: No domestic car is
designed to pull/ drift left. All cars sold in the UK have an expected range to resist "road crown deviation". Because the road crown deforms the nsf/ osf tyre circumference so depending on the tyres "aspect ratio" an eventual pneumatic steer is inevitable.
2: The Omega has a very poor "DI" dynamic index. This means the roll centre during weight transitions requires very high front coil rates. In reply this also means a long damper stroke. In summary the coil-over-oil dynamics is extremely fluid..... "do we all agree on that!"
3: The above suggests "static Geometry" as a modifier can be deemed as less than perfect! Well we all know that! That's why there are so many complaints here.... so what to do?
4: Historically the static front camber positions does not comply with the dynamics. Many past examples in measurement and final corrective positions can suggest a "global" set-up but this is not the law! so the actual complaint -ver- positions must be read on the fly so to speak..... But we have another problem?
5: Camber Change - If a wheel has positive Castor, then the top of the wheel leans into the corner whichever way it is steered. The change in Camber is approximately:
Camber Change = Castor x steer-angle / 60 (measured in degrees)
Example: Camber Change = 6 degrees
Steer-angle = 10 degrees
Then:- Camber Change = 6 x 10/ 60 = 1.0 degree
The change in camber that results from positive Castor is beneficial to the grip of both front wheels during cornering, providing it isn't excessive. A negative Castor (top of the steer-axis leaning forwards) changes the wheel Camber angles in the 'wrong' direction during cornering, this is not desirable.
Self-Centering phenomenon
Castor has a self-centring effect that is similar to that of SJI/KPI. As the wheel is steered away from straight-ahead its Camber angle changes and more weight is carried by one edge of the wheel. This shifts the wheelprint centre sideways and the offset force then acts to return the wheel to straight-ahead. As with the SAI/KPI self-centring this effect is proportional to the Castor and to the radius of curvature of the tyre.
Self-centring exists even if the tyre is narrow, although it is almost non-existent at small steer-angles. It is very evident on wide, flat cross-section tyres with stiff sidewalls.
Castor Trail
The common argument for the trail is wrong and it aggravates me since the example has become a seed for most attempting to explain the trail.
Geometry= X. Y. Z Three dimensions... There is no exact law or solution only understanding and recognition... And finally team work between the tech and the owner.
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Topic: Wheel alignment (Read 7466 times)