The new Toyota Supra is somewhat controversial given its tuner legacy and direct relation to the BMW Z4. The general consensus seems to be that it’s good, but not great. One of the reasons why, as professional race drivers will tell you, is the rear suspension. It suffers from alignment issues that have finally been fixed thanks to a kit from German tuning company Verkline, but this kit is more than some new tie rods. It completely replaces the Supra’s rear suspension, save for a few parts, and the reason why is interesting. That is, if you find suspension kinematics interesting.
When compressed, the rear suspension’s toe—the neutral “steered” position of the wheel, typically a few degrees in or out—changes drastically, going from positive (the wheels facing out) to negative (the wheels facing in). Under braking, the rear suspension unloads, changing toe rapidly and crossing zero degrees toe in transition, a place you don’t want to be in while driving fast. As a result of this toe change, referred to as “bump steer” by some, the rear end has the tendency to squirm around, changing the direction of the car enough that it could possibly lead to a driver overcorrecting and getting into an accident, as explained in the clip below.