You bought coilovers. Or maybe you're shopping for your first set. Either way, the spring rate numbers — 12k/10k, 6k/4k, 14k/8k — can get confusing fast. What do they mean? And more importantly, how do you pick the right setup for your driving style?
In this guide, we’ll break down what coilover spring rates actually do, how they affect handling, and how to choose the ideal rate for drifting, grip, or street builds.
What Does Spring Rate Actually Mean?
Spring rate measures how much force it takes to compress a spring one unit of distance. In metric coilovers, that’s in kilograms per millimeter (kg/mm), often shown as “k”.
Example:
- A 6k spring requires 6kg of force to compress 1mm
- A 12k spring is twice as stiff as a 6k
High vs Low Spring Rates
- Higher rates: Stiffer ride, less body movement, more control at the cost of comfort
- Lower rates: Softer ride, more body roll, better compliance but more chassis movement
Spring rates need to match your shock valving. Don’t throw a 14k spring on a shock designed for 8k — you’ll ruin handling and ride quality.
Best Coilover Spring Rates for Drifting
Drifting is about balance, weight transfer, and response. Most drift setups run:
- Stiffer front: Improves initiation and steering feedback
- Softer rear: Allows better rotation and throttle control
SLR Drift-Spec Coilovers often run setups like 12k front / 5k rear for cars like the 350Z and E46 — tested by actual drift drivers across ProAm and grassroots levels.
Best Spring Rates for Grip/Track Use
Grip setups usually aim for a more balanced front and rear rate. Key factors:
- Track surface
- Tire size and compound
- Aero load and chassis stiffness
A balanced setup might be 8k/10k or 10k/12k depending on the car. It’s about minimizing chassis upset while keeping tires planted through corners.
Best Spring Rates for Street Driving
If your car is a daily driver or weekend canyon carver, comfort matters. Lower spring rates and progressive damping are ideal.
Typical street-friendly rates: 6k/6k, 7k/5k depending on weight and tire setup.
Coilovers Are More Than Just Springs
Spring rate is just one part of the suspension equation. Damping, preload, shock travel, and suspension geometry all affect performance.
If you're looking for a proven coilover setup with the right spring rate and drift-specific valving, check out our full breakdown: What Are Coilovers?
