Effect of Cornering Loads on Steer

Cornering loads will also have a pronounced effect upon suspension geometry and vehicle trim. The figure below shows the steer angles at each corner of the vehicle, again with (red) and without (green) the introduction of tire cornering forces. Once again, the green measurements do not reflect what happens in real life. The red traces, measured on the Morse Measurements K&C rig and including proper tire cornering forces, provide a more accurate representation of vehicle steer trim while cornering:

As shown above, a roll oversteer set-up in the front suspension has degraded into severe roll understeer when tire cornering loads are taken into account. This clearly demonstrates the importance of the “C” (for Compliance) in K&C testing. It also raises questions about what else is happening to the suspension under load. Again, only a properly set up K&C test will get after this kind of information.