A corner damper system with a decoupled heave element, allowing roll and heave to be tuned independently.
The architecture retains conventional corner dampers and adds a separate heave element, so heave stiffness can be set independently of the roll rate the corners provide. With an undertray on the car, heave control directly affects aerodynamic performance through ride height stability, while roll stiffness needs to remain free for tuning lateral load transfer. The concept builds on my previous LLTD work, in which roll stiffness distribution was shifted from 57% front to 46.1% front to move the car from understeer limited toward neutral.
I am also evaluating an active ride height capability, using a ride height sensor to electronically actuate the heave cylinder, extending or compressing it to hold a target ride height as aerodynamic load changes with speed.
The open decision is the heave element itself. Hydraulic, pneumatic, and air spring/damper implementations each trade differently across tunability, weight, and reliability, and on an FSAE car a system that performs well but fails during endurance provides no competitive benefit.
Commercial off the shelf decoupled systems exist for FSAE, but they are expensive and heavy, and packaging one costs CG height and mass. A custom solution is only worth pursuing if it beats the COTS option on those terms, which sets the constraint the design has to work inside.
The active ride height element must actuate fast enough to respond to load changes in real time and precise enough that the correction is worth making. Identifying an actuator that meets both requirements at acceptable weight is the current work.
In progress. Success criterion is that a roll stiffness change can be made without shifting the aerodynamic platform.