If using on mobile, switch to desktop version. This is a vehicle dynamics ride frequency calculator. Click Calculate to produce suspension and sprung mass frequency and node derivations used for target setting vehicle performance and tuning. This tool can save a tuner time by reducing the amount of changes and evals needed to dial in the targeted performance of the vehicle. Whether its matching a setup that is known to perform well, or evaluating current status and what knobs can be turned with the vehicle component tunability options to achieve a goal as close to the target as computable. To compare 2 different settings, after you calculate your baseline, click Set Reference/Baseline to store those values. Any new calculations will populate on the page with the reference values maintained on the plot with shaded points and the front, rear, bounce, and pitch frequencies labeled on the points. Using stiffness value of the ride spring acting through the motion ratio to the tire patch, the net result of bushing torsional stiffness on the tire patch, the tire stiffness, vehicle geometries and masses, the natural frequencies of the vehicles suspension and the point nodes at which the sprung mass heaves and rotates about are directly calculatable. With a scale, a measuring tape, and some ingenuity, these inputs can all be measured in your own garage! Accuracy to be determined of course, however the more accurate the result needed, more effort in acquiring an accurate result tags along. An in-depth video accompanies this calculator walking through methods of collecting the input data reliably and accurately. The inertia is calculated from the NHTSA pitch inertia vs curb weight study correlating full vehicle weight to pitch inertia with confidence. Unsprung wheel/suspension inertia contributions are then reduced from that value via the difference in CG positions of the full vehicle CG, and the unsprung CG masses. The Dynamic Pitch Index is a modifier input to the NHTSA equation with low roofline and short wheelbase vehicles like Fiat 500 and Yugo's down around 0.8, and a Suburban or heavy duty truck closer to 1.3. Input guesses can be found online, directly measured, or outright guessed for the calculator to be useful. The tool is used for initial setup, making directionally correct changes to a currently known setup, or just learning "What happens when?". The user can mess around with spring rates or simulate swapping OEM rubber bushings for PTFE wrapped spherical joints. Maybe the car rode over bumps very flat when stock, but not so much after weight reduction and a drifted weight distribution. The user can recalculate a new front or rear spring to match the ride ratio and pitch nodes to get the ride behavior back to how it was before. Or a simple spring swap from a set of bouncy coilovers could yield dramatic improvements to comfort and balance while likely improving performance and lap times. When switching units, the values auto convert, so it also works as a unit converter. To see the standard units simply delete the value in the box and they will appear. The chart plots the wheelbase along with the front and rear weight distribution intersecting at the full vehicle CG at a height according the the user input. The sprung mass CG, bounce, and pitch nodes run along the same plane. The unsprung masses are at the tire SLR or calculated tire center by tire size in height, proportional to the wheelbase with the wheel end frequencies shown. The front of the vehicle is at zero. The values below the shown points are for the reference data and the values above the points are for the current data. Feel free to reach out for improvements or questions about the calculator. As time progresses I will add more functionality, but I would like to get all of my dynamics and powertrain development tools roughed into the toolbox first.