K&C
and 7-post: What's the difference?
The AB Dynamics K&C test machine at Morse Measurements is not a 7-post shaker
rig. We don’t “shake” cars or report results in the frequency domain. We don’t
use hydraulics, and the results are not difficult to understand.
7-post shaker rigs are used primarily for tuning
suspension dampers. The typical goals are to (1) Minimize contact patch load variation over known
road/track profiles, and (2) Improve vehicle pitch behavior for improved aerodynamics.
K&C rigs are used for tuning everything
else in the suspension, beyond the dampers. The typical goals are to (1) Optimize the loaded and unloaded suspension
geometry over known road/track profiles, and (2) Maximize the mechanical grip of each tire by optimizing longitudinal and
lateral weight transfer.
K&C
testing and 7-post testing actually compliment each other in many ways because, as shown in the table below, K&C
tests capture information that is just not available from shaker rig testing:
