Are you looking to fine-tune your vehicle’s suspension but not sure where to start? Fret not, this article is designed to guide you through this journey. The suspension system of a car is the cornerstone for a comfortable and controlled ride.

Baseline Suspension Calculator

Weight: Motion Ratio: Ride Frequency:

What is the Suspension Spring Rate?

The spring rate is a crucial component in your vehicle’s suspension system. It determines the responsiveness of your springs to the weight they carry. It’s calculated by finding how much force is needed to compress the spring by one inch (for coil springs), or in metric units, the force required to compress the spring by one millimeter (N/mm). The higher the spring rate, the stiffer the spring.

Breaking Down the Suspension Calculator

Our suspension calculator requires three key parameters to calculate the spring rate:

1. Weight – This is the total weight of your vehicle. Usually, this information can be found in your car’s manual or on a sticker located on the driver’s side door jamb. For a more precise calculation, you should consider the weight distribution of the vehicle – the weight over the front and rear axles.
2. Motion Ratio – The motion ratio of your suspension is the relationship between the wheel’s movement and the corresponding movement of the spring. It varies based on the design of your suspension system. Usually, you can find this information in your car’s manual, consult with the manufacturer or measure it physically with the suspension at its designed ride height.
3. Ride Frequency – This is a measure of how quickly the suspension system compresses and extends under different forces. A high ride frequency suggests a stiffer ride, while a lower ride frequency indicates a softer, more comfortable ride. It is usually chosen based on driver’s preference, riding conditions and vehicle usage. For a passenger car, a typical ride frequency might be around 1.0-1.6 Hz, while a racing car may have a higher ride frequency above 2.0 Hz.

How to Use the Calculator

The calculator comes in the form of a simple and user-friendly form. Here is how to use it:

1. Input the Weight of your vehicle in the respective field. Make sure to input the weight in the same unit you will be expecting the spring rate result in (e.g., pounds for lbs/in or kilograms for N/mm).
2. Input the Motion Ratio of your suspension system. This value is a ratio, so it is unitless.
3. Input the Ride Frequency you are aiming for in your setup.
4. Click the ‘Calculate’ button.

The calculator will perform the necessary calculations and display the required spring rate for your suspension system.

The Importance of Tuning your Suspension

The suspension system is not a one-size-fits-all solution. Each car and driver will have different requirements based on the car’s weight, its distribution, the car’s purpose (racing, off-roading, city-driving), and the driver’s preferences. By using our calculator, you can start to understand how changing one element can significantly impact the car’s performance.