Yes, but with caveats.
Certainly, four post rig tests provide an insight into the way the suspension
interacts with other elements of a vehicle, and can reveal characteristics
that are difficult to identify otherwise. Equally, vehicle deficiencies
that have been hidden by a particular suspension set-up (and cannot be detected
by a rig test) may well be exposed if the set-up is changed radically. Occasional
spectacular successes and spectacular failures
can be attributed to these features of a four post rig test.
More usually, however, a test rig is simply one of the tools that are used
to achieve and maintain optimal suspension performance for a vehicle and,
for example, the rigs at Cranfield and Thetford have been used on a regular
basis by the last five winners of the BTCC championship.
It is important to realise that rig tests in isolation are unlikely to
yield an optimal suspension set-up.
The suspension of a vehicle performs several functions, some of them conflicting
(more). For example, a linear style of damping is
most effective at dissipating energy from a vehicle, but a linear style
of damping controlling the steered wheels provides little feedback to the
driver and implies a large steering time constant. It follows that moving
the style of damping towards linear might improve the vehicle, but is likely
to make it more difficult to drive; at best, a driver will have to adapt
his driving technique (which requires track time); at worst the driver/vehicle
combination will be slower.
The requirement to control the attitude and ride height of an "aerodynamic"
vehicle at high speeds further complicates matters (more),
and the task of blending low and high speed performance of a suspension
is an exacting one.