Adjusting the height of your BC Racing coilovers is a great way to dial in your car’s stance and handling. This guide will show you How To Adjust Bc Coilovers Height the right way, ensuring you get the perfect setup without compromising safety or performance. It’s a straightforward process once you understand the key steps and precautions.
Getting it wrong can lead to poor handling, premature wear, or even damage. But with the right tools and a methodical approach, you can achieve that perfect look and feel. Let’s get your car sitting exactly how you want it.
How To Adjust Bc Coilovers Height
Before you start turning any wrenches, it’s crucial to gather everything you need and understand what you’re adjusting. BC Racing coilovers use a threaded spring perch system for height adjustment, which is separate from the damper’s preload setting. This gives you precise control.
You’ll be working on the main locking collars that hold the spring perch in place. Always adjust from the bottom of the coilover, not the top. This maintains your shock travel and keeps the suspension working as designed.
Essential Tools and Safety Gear
You don’t need a full mechanic’s shop, but having the right tools makes the job safer and easier. Trying to improvise can strip the collars or lead to injury.
Here’s what you should have ready:
* Jack and Jack Stands: Never rely on a jack alone. Use sturdy jack stands on level, solid ground.
* Coilover Wrenches (Spanner Wrenches): BC coilovers come with these. You typically need two to loosen the locking collars.
* Penetrating Oil (like WD-40): Helpful if the collars are seized or dirty from road use.
* Socket Set and Wrenches: For removing the wheel.
* Torque Wrench: For properly tightening the lug nuts and, if needed, the coilover collars.
* Measuring Tape or Caliper: For precise, consistent measurements.
* Safety Glasses and Gloves: Protect your eyes from debris and your hands from sharp edges.
Pre-Adjustment Preparation
A little prep work prevents mistakes and ensures consistent results across all four corners of your car. Rushing this stage is the most common error.
First, park on a perfectly flat surface. An uneven garage floor or driveway will give you false measurements. Then, you need to take your car’s current ride height measurements.
You should measure from a fixed point on the wheel hub center straight up to the fender lip. Do this for all four wheels and write the numbers down. This is your baseline. Using the fender itself as the only reference point is unreliable, as tire pressure and wear can affect it.
Step-by-Step Height Adjustment Process
Now, let’s walk through the adjustment itself. We’ll do this one corner at a time for control and accuracy.
Step 1: Loosen the Wheel and Secure the Vehicle
Start by loosening the lug nuts on the wheel you’re adjusting. Then, jack up the car and place it securely on a jack stand. You can now fully remove the wheel for maximum access and visibility. Always double-check the car is stable.
Step 2: Locate and Clean the Adjustment Collars
With the wheel off, you’ll clearly see the coilover assembly. Identify the two locking collars on the threaded shock body. They sit below the spring perch. Spray a little penetrating oil on the threads and collars if they look corroded. Wipe away any major grime with a rag.
Step 3: Unlock the Collars
This is the key step. Take your two spanner wrenches. Place one on the top locking collar (the one that locks against the spring perch) and the other on the bottom locking collar (the one that locks against the first). Apply force in opposite directions to break the lock. You usually turn the top collar counter-clockwise and the bottom collar clockwise.
Once they are loose from each other, you can spin them together up or down the threads to make the adjustment. Remember, spinning the collars up the shock body (raising the spring perch) will lower the car. Spinning them down (lowering the spring perch) will raise the car.
Step 4: Make the Adjustment
Decide how much you want to change the height. For a small, precise change, you can measure the thread exposure. For larger changes, spin the collars several full turns. It’s better to make a conservative adjustment first, remeasure, and then fine-tune.
A good tip is to count the number of full turns you make on each corner for consistency. If you want to lower the car by 10mm, and one full turn gives you 3mm, you’d do about three full turns on each corner.
Step 5: Re-lock the Collars and Reinstall
Once the spring perch is at your desired height, you must re-lock the collars. Hold the bottom collar steady with one spanner wrench. Use the other to tighten the top collar firmly down against it. They must be locked tightly together to prevent the height from shifting during driving, which is very dangerous.
You can now reinstall the wheel. Hand-tighten the lug nuts, lower the car to the ground, and then use your torque wrench to tighten the lug nuts to your vehicle’s specified torque in a star pattern.
Post-Adjustment Steps and Fine-Tuning
You’re not quite done after adjusting all four corners. The suspension needs to settle, and you need to verify your work.
Drive the car slowly around the block, then park it back on the same flat surface. Let it sit for a few minutes so the suspension settles into its new position. Now, retake your measurements from the hub center to the fender on all four wheels.
Compare these to your target heights. If one corner is off, you may need to make a minor tweak. Remember that adjusting one side can slightly affect the other due to the anti-roll bar, so final checks are essential.
Critical Alignment Check
This is non-negotiable. Changing your ride height alters your car’s alignment geometry, specifically camber and toe. Driving with misaligned wheels will cause uneven tire wear and poor handling.
After you are completely satisfied with your new height, you must take your car for a professional alignment. Tell the alignment shop you’ve adjusted your coilovers so they can set it to your desired specifications. This final step protects your investment in both tires and suspension.
Troubleshooting Common Issues
Sometimes, things don’t go perfectly smoothly. Here are solutions to common problems.
* Seized or Stuck Collars: Don’t force them. Apply more penetrating oil and let it soak. You can gently tap the spanner wrench with a rubber mallet to shock it loose. Using heat is risky as it can damage the shock seals.
* Uneven Height After Adjustment: Re-measure from the hub. If it’s still off, ensure the collars are locked at exactly the same thread position. Also, check that the suspension was settled when you measured.
* Rattling or Clunking Noise After Adjustment: This often means the collars are not locked tightly together and have come loose. It could also mean the top mount nut needs checking. Investigate immediately—do not ignore suspension noises.
* Car Handles Poorly: This is almost certainly an alignment issue. Get the alignment done before judging the handling. Also, ensure you haven’t lowered the car so much that the tires rub on the fenders.
Maintaining Your BC Coilovers
Regular maintenance keeps them adjusting smoothly and performing well. Every few months, or after driving in bad weather, visually inspect the collars and threads for excessive dirt or corrosion. A light spray of silicone lubricant on the threads can prevent seizing.
Avoid using high-pressure water directly on the coilover body when washing your car. Check the locking collars for tightness periodically, especially after the first 100 miles after an adjustment.
Frequently Asked Questions (FAQ)
Q: Do I need to adjust the preload when changing height?
A: No. On BC Racing coilovers, height is adjusted via the spring perch, not preload. You should not adjust the top spring collar for routine height changes. Preload is set from the factory for your spring rate.
Q: How low can I go with BC coilovers?
A: They offer a wide range, but extremely low settings can lead to bottoming out the shock, tire rub, and compromised handling. Always maintain some shock travel for safety and ride quality.
Q: Can I adjust the height with the weight of the car on the suspension?
A: It is not recommended. The weight of the car puts immense pressure on the collars and threads, making them very difficult to turn and increasing the risk of damage or injury. Always jack up the car and support it with stands.
Q: How often should I check the coilover collar tightness?
A: It’s a good habit to check them every time you rotate your tires or every 5,000 miles. A quick visual and a tap with the spanner wrench to ensure they’re snug is sufficient.
Q: My car is lower in the front after adjusting all corners the same. Why?
A: Vehicles often have different front and rear weight distributions. Equal thread adjustment doesn’t always mean equal height change. Always go by your hub-to-fender measurements, not the number of turns.
Adjusting your BC Racing coilovers is a satisfying task that puts you in direct control of your car’s character. By following this guide, using the right tools, and prioritizing safety with jack stands and a post-adjustment alignment, you can achieve the perfect stance and improved handling. Take your time, measure twice, and enjoy the results of your work.