Coilovers offer a fantastic way to fine-tune your car's handling and ride quality, but setting the preload correctly is crucial for optimal performance and longevity. Incorrect preload can lead to poor handling, premature wear, and even damage to your suspension components. This guide will walk you through the process, answering common questions along the way.
What is Preload on Coilovers?
Preload refers to the initial compression applied to the coilover spring before any weight is applied from the vehicle. Think of it as the spring's "resting" position. Proper preload ensures the spring is always working within its optimal range, providing consistent damping and support. Too little preload, and the spring might bottom out easily. Too much preload, and the ride will be harsh and the spring may bind or break.
How to Determine the Correct Preload?
There isn't a single "correct" preload for all coilovers; it depends on factors like your vehicle's weight, driving style, and the specific coilovers you've installed. However, here's a general guideline and how to proceed:
1. Consult Your Coilovers' Instructions: The manufacturer's instructions should provide a recommended starting point for preload. This is your best starting point. Always prioritize the manufacturer's recommendations.
2. Visual Inspection: Once installed, visually inspect the coilover. The spring should have a reasonable amount of space between the top and bottom perches before any weight is applied to the suspension. There should be a visible amount of thread showing on the body of the coilover itself above the spring perch. This varies between models, but you are generally looking to avoid the spring being fully compressed or having excessive space.
3. Measuring Ride Height: Many people use ride height as an indicator. However, this isn't a reliable measure of preload. Ride height is affected by many factors. You're better off focusing on the preload itself.
4. Weighing Your Vehicle: Knowing the weight distribution of your vehicle (front and rear) can help you dial in the preload more precisely. This is advanced and rarely necessary for a typical street car.
5. Fine-Tuning through Testing: After setting an initial preload, test drive the vehicle. Pay close attention to the ride quality and handling. Adjust the preload in small increments and retest until you achieve the desired balance between comfort and performance.
What Tools Do I Need to Adjust Preload?
The tools needed will vary depending on the design of your coilovers, but generally, you'll need:
- A wrench or socket: This will depend on the size of the adjusting nut on your coilovers.
- Jack and jack stands: Essential for safely lifting and supporting your vehicle.
- Wheel chocks: To prevent accidental rolling.
- Measuring tape: Optional, for monitoring changes in ride height.
How to Actually Adjust the Preload
This process involves turning the adjusting nut on the coilover body, usually located at the bottom of the unit. Turning the nut clockwise increases the preload and turning it counter-clockwise decreases it. Always make adjustments in small increments (1/4 to 1/2 a turn at a time), testing after each adjustment. Never adjust the preload while the vehicle is on the ground. Always follow the specific instructions included with your coilover kit.
How Much Preload is Too Much?
Excessive preload is easily recognized. The spring will be very tight, almost fully compressed, and you'll notice a very harsh ride. The car will feel bouncy or stiff.
How Do I Know If My Preload is Too Low?
If your preload is too low, the car will feel soft and wallowy, and the spring could potentially bottom out, especially under cornering or braking.
What Happens If I Get the Preload Wrong?
Incorrect preload can lead to poor handling, uneven tire wear, premature component wear, and potentially damage your suspension.
Can I Adjust Preload Myself?
Yes, but only if you have the necessary mechanical skills and tools, and are comfortable working on your vehicle's suspension. If you are uncertain, it's always best to consult a qualified mechanic.
Remember: Safety is paramount. Always work on your car in a safe, well-lit area. If you're unsure about any part of the process, seek professional help. Correct preload is crucial for optimal performance, but it's only one component of a well-tuned suspension system.
