Control Arm - Lower-Inner Front Bushing
ALIGNMENT SETTINGS ? WHAT
The simple answer is that there is no such thing!
I know we have probably given more information here than most
people wanted, but even this only scratches the surface of the
available information and variables that need to be considered when
contemplating optimum wheel alignment settings.
The most important thing and something we can not stress enough
is the fact that alignment settings are NOT an ?absolute truth? that can be held up as an
undisputed rule. It is a dynamic process with the ?correct value?
varying from driver to driver, car to car not to mention the
DYNAMIC & STATIC ? WHAT ARE YOU TALKING ABOUT
Typically used when discussing wheel alignment and geometry. By
this, Whiteline are referring to the difference in alignment angles
between a stationary and a moving vehicle. That is, the same
vehicle will typically have different caster, camber and toe
readings when it is moving compared to when the alignment was done
in static form in the workshop.
In an ideal world, all wheel alignments would be done on a
dynamic wheel aligner but these are expensive and quite rare. This
concept is very important, as the only suspension angles that
really matter are those present while the vehicle is moving
(dynamic). What is done to the vehicle?s alignment while the
vehicle is stationary, (static) is a process of trying to predict
the levels of change while the vehicle is moving and setting the
angles according to these predictions.
Whiteline puts a great deal of emphasis on the dynamic geometry
so rigorous road testing is essential to ensure that the
predictions are valid.
- ?Anti? Geometry
CAMBER ? WHAT IS IT
Camber is the inclination of the wheel from the vertical when
viewed from the front. When the top of the wheel leans out you have
positive camber, lean in equal?s negative camber.
Static negative camber is used to compensate for body roll, body
distortion and tyre roll under when cornering. Stiffer bodies and
tyre sidewalls are in and unnecessary suspension compliance is out.
Therefore the previous requirements for large amounts of static
negative camber are disappearing. Whiteline strut braces are good
for maintaining camber angles under cornering loads as they further
minimise body flex.
Its important to highlight the fact that camber settings are
ultimately a personal thing. That is, Whiteline can provide an
indicative range to start from but the final number will depend on
your driving style, average driving conditions, tyre size and many
other things. You need to start with a relevant number, then
monitor tyre wear and compensate if necessary.
Whiteline have a range of camber adjusting products available to
achieve the optimum settings.
CASTER ? WHAT IS IT
Caster is the backward or forward tilt of the steering axis.
Vehicle manufacturers are aware of the advantages of caster and as
each new model is released the amount of caster specified
Why, because the disadvantages of high levels of castor are
being overcome. Rack and pinion steering means less play, lower
Ackerman levels, smaller scrub radius (zero is now very common),
better and lower profile radial tyres means less sidewall
deflection and higher tolerance to greater slip angles. But the
greatest obstacle, that of heavy steering effort, has all but
disappeared with the universal acceptance of power steering.
High levels of positive caster equate to dynamic negative camber
on turn when you need it most. Whiteline continues to put heavy
emphasis on additional positive caster when designing new
If you were able to view the front tyres of a vehicle from above
the car, you would expect them to look exactly parallel to each
other. In fact, they rarely are. The difference in distance between
the front edge of the tyres and the rear edge is called toe. Toe
describes how close to parallel the two tyres are, and whether they
are toed-in (closer at the front of the tyre) or toed-out (closer
at the rear of the tyre). The goal of toe is to provide proper tyre
wear through various driving conditions. The amount of toe your
suspension is set to varies by the drive layout of your vehicle,
driving preference, and car?s handling characteristics.
On a rear-wheel-driven car, acceleration forces on the tyre tend
t o push the front tyres back slightly in the wheel well. Static
toe-in will result in a zero-toe situation at speed. For a
front-wheel-driven vehicle, the front wheels will pull themselves
forward in the wheel wells under acceleration. This happens because
as the (driven) front wheels claw for traction, they pull
themselves forward, dragging the rest of the car along. For this
situation, static toe-out will result in a zero-toe condition at
speed. Assuming that the rest of the suspension is correctly
aligned and maintained, and the tyres properly inflated, toe-in
will result in additional understeer for the car. In a corner the
inside front tyre will turn at less of an angle than the outside
tyre. Additionally, excessive toe-in will result in premature tyre
wear through feathering, and increased fuel consumption.
Conversely, toe-out will result in additional oversteer for the
vehicle. This occurs as the inside front tyre turns at a greater
angle than the outside tyre. Thus, in a corner, the inside tyre is
trying to turn even more than the heavily-loaded outside tyre.
Excessive toe-out will also result in premature tyre wear due to
feathering, and increased fuel consumption.
?Anti? features in suspension systems are a characteristic that can
be used to influence the stiffness of the front or rear suspension
under traction forces(under braking or accelerating). The
individual terms are relatively straightforward and
self-explanatory with the ?anti? reducing or totally restricting
the characteristic (lifting or diving). In the front suspension
there may be levels of anti-dive during braking and anti-lift
during accelerating (assuming traction to the front wheels is
present), similarly in the rear there could be anti lift during
braking and anti-squat during acceleration.
It should also be noted that these characteristic can also be
reversed into a ?pro? characteristic (as in pro-lift at the front
under braking). Anti features can only be implemented under the
influence of the braking or accelerating forces at the wheels, for
example a rear wheel drive vehicle cannot have an anti-lift
characteristic in the front (as there is no drive to the front
With the ALK fitted to the Subaru
WRX, a softer suspension will be present
during braking and accelerating. This will help traction, as the
wheel will be able to track the ground more precisely. Also in
terms of balance the front end will have a proportionally lower
roll resistance during traction or braking, aiding in reducing the
power understeer effect that is present in these cars.