This tool performs an optimization of a vehicle's setup across an entire circuit using steady-state simulations. Both the optimizer and vehicle model are implemented in C++ and operate directly on physical setup parameters such as suspension stiffness, aerodynamic balance, and wheel alignment.

For each candidate setup, the vehicle model is evaluated at corner entry and apex to compute four core handling metrics: Grip, Balance, Control, and Stability. These per-corner evaluations are aggregated into a lap-level objective defined by the engineer, allowing the optimizer to select a single vehicle setup that best satisfies the target handling profile across the full track.

The analysis focuses on four handling metrics that describe the vehicle's cornering behavior:

• Grip: The maximum lateral acceleration (peak steady-state Ay) the car can generate. On a yaw moment diagram, this corresponds to the leftmost and rightmost points of the curve. Maximizing grip is a primary objective for any race car, however, grip alone is insufficient. A setup that achieves high lateral acceleration but lacks proper balance is ultimately unusable in practice.
• Balance: Balance describes the vehicle's understeer or oversteer tendency at peak lateral acceleration. A yaw moment acting in the direction of the turn indicates oversteer, while a yaw moment opposing the turn indicates understeer. Ideally, balance is near zero at peak grip, producing a neutral and driveable limit behavior.
• Control: How accurately the car follows the driver's intended path for a given steering input. Control is defined as the yaw moment generated per degree of steering angle (∂Mz/∂δ) for a given chassis sideslip. Steering that produces yaw in the direction of the turn indicates predictable, positive control, while a weak or opposing response indicates reduced or unstable control.
• Stability: How well the car maintains its intended trajectory when disturbed by a bump, crosswind, or contact with another car. Stability is quantified by the change in yaw moment with respect to body slip angle β (∂Mz/∂β) for a given steering angle. A restoring yaw moment opposes the slip and allows the car to naturally re-align, while a reinforcing yaw moment amplifies the rotation, causing the car to continue stepping out unless corrected. The goal is to create a stabilizing tendency/restoring yaw moment so small disturbances decay rather than grow.

The table below summarizes each corner of the Indianapolis Motor Speedway Road Course. For every turn, entry and apex conditions are characterized by average speed, chassis sideslip, and steering angle for a GT3-class vehicle. These operating states, together with the vehicle setup, serve as inputs to model simulations used to evaluate four handling metrics.

The table also incorporates driver feedback. Driver ratings for grip, balance, control, and stability are mapped to their corresponding objective metrics, allowing the engineer to identify the operating conditions under which the driver perceived the vehicle as ideal. Grip, control, and stability are rated on a 0-10 scale, while balance is rated on a -5 to +5 scale (understeer to oversteer).

This combined view allows race engineers to identify where setup compromises are most critical and which corners most strongly influence the optimal whole-lap configuration.

To generate results, millions of setup combinations are evaluated using handling metrics computed from model simulations. Aerodynamic balance, front and rear spring stiffness, anti-roll bar rates, weight distribution, ride heights, and alignment parameters (toe and camber) are varied within defined limits. For each corner of the circuit, the optimizer selects the setup that best meets the target Grip, Balance, Control, and Stability values specified by the engineer.

In the example below, minimum and maximum bounds are defined for each vehicle parameter, constraining the search space to physically realistic values. Within these bounds, the solver evaluates candidate values within this interval and selects the rate that best satisfies the combined Grip, Balance, Control, and Stability objectives for each corner. In this example, the front spring rate is limited to a range of 128-158 N/mm. This approach ensures the final setup represents an optimal trade-off within feasible design limits rather than an unconstrained numerical optimum.

Baseline values represent the handling metrics produced by the car's original setup prior to any optimization. This setup reflects the engineer's starting configuration and serves as the reference point for comparison. Optimized values correspond to the handling metrics achieved using the setup selected by the optimizer.

The yaw moment diagram provides a compact representation of a vehicle's steady-state handling behavior at a given speed and setup. Each curve corresponds to either a constant steering angle (red) or a constant sideslip angle (blue), capturing how the setup influences all four handling metrics simultaneously. The lateral extrema of the curves define available grip, their vertical offset at these points indicates balance, the slope of the steering-angle curves relates to control, and the slope of the sideslip-angle curves reflects stability.

At the intersection with the zero yaw-moment line, the vehicle is in a neutral steer condition. The lateral extrema correspond to the maximum achievable lateral acceleration in left- and right-hand turns. For a given turn, a yaw moment opposing the direction of the turn indicates an understeering, front-limited condition (“plow” at the limit), while a yaw moment in the same direction as the turn indicates an oversteering, rear-limited condition with a tendency to rotate. The overall shape of the curves and their slopes therefore quantify the available yaw-moment reserve for control and the inherent stability of the vehicle near the limit, provided the sign convention and turn direction are accounted for explicitly.