CUSCO Street ZERO A Coilover Kit

1. Product Overview

The CUSCO Street ZERO A Coilover Kit is a high-performance suspension system designed to enhance the driving dynamics and aesthetics of your Suzuki Swift Sports (ZC32S). This kit features full-length adjustable ride height and 40-step damping force adjustment, allowing for precise tuning to achieve optimal ride comfort and handling stability across various driving conditions.

Key features include a vehicle-specific design to ensure adequate bump stroke even at lowered settings, nickel-chrome plated adjustment threads for corrosion resistance, and high-polymer thrust sheets to prevent lock nut loosening and reduce noise. The system also incorporates a CPRV (Pressure Proper Valve) to maintain consistent damping force at low speeds, contributing to superior ride quality and handling.

Figure 1: CUSCO Street ZERO A branding and a vehicle equipped with CUSCO suspension.

2. Key Features and Components

• Full-Length Ride Height Adjustment: Allows for precise vehicle height adjustments without compromising suspension stroke.
• 40-Step Damping Force Adjustment: Provides a wide range of damping settings, from soft to hard, to fine-tune ride comfort and handling characteristics. Adjustments can be made easily with a knurled dial, no tools required.
• CPRV (Pressure Proper Valve): Optimizes damping force at low piston speeds to prevent excessive drops, ensuring consistent ride quality and high handling stability across all speed ranges.
• Nickel-Chrome Plated Adjustment Threads: The threaded sections are treated with nickel-chrome plating to protect against rust, sand, and dust, ensuring smooth and reliable height adjustments over time.
• High-Polymer Thrust Sheets: Integrated to prevent lock nut loosening and reduce unwanted noise, contributing to overall product quality and quietness.
• Vehicle-Specific Design: Each kit is engineered specifically for the target vehicle model, ensuring optimal fitment and performance, including sufficient bump stroke even at lowered settings.
• Reinforced Rubber Upper Mounts: For sports and sedan models, reinforced rubber upper mounts are adopted to improve comfort and reduce noise. (Note: This specific model, 619-62N-CB, may utilize OEM upper mounts for the front and rear, as indicated by 'upper mountless' in some specifications, meaning new upper mounts are not included in the kit and existing ones are reused or purchased separately.)

Figure 2: Key features of the CUSCO Street ZERO A coilover, including damping adjustment and CPRV.

Figure 3: Further details on product design, e-con2 compatibility, and material quality.

3. Setup and Installation

Installation of the CUSCO Street ZERO A Coilover Kit should be performed by a qualified professional or an experienced mechanic. Incorrect installation can lead to vehicle damage, poor performance, or safety hazards.

3.1 Pre-Installation Checks

• Verify that the coilover kit model (619-62N-CB) is compatible with your Suzuki Swift Sports (ZC32S, 2011/12~).
• Inspect all components for any shipping damage or missing parts.
• Gather all necessary tools, including jacks, jack stands, wrenches, sockets, torque wrenches, and spring compressors (if required for upper mount transfer).

3.2 General Installation Steps (Summary)

1. Safely lift the vehicle and secure it on jack stands.
2. Remove the wheels.
3. Disconnect brake lines, ABS sensors, and sway bar links from the OEM suspension.
4. Remove the OEM shock absorbers and springs.
5. If applicable, transfer OEM upper mounts to the new CUSCO coilovers.
6. Install the CUSCO coilovers, ensuring all bolts are torqued to manufacturer specifications.
7. Reconnect all disconnected components.
8. Reinstall wheels and lower the vehicle.
9. Perform an initial ride height adjustment.
10. After installation, a professional wheel alignment is highly recommended.

4. Operating and Adjustment

The CUSCO Street ZERO A coilovers offer precise adjustments for ride height and damping force to tailor your vehicle's performance to your preferences.

4.1 Ride Height Adjustment

The front coilovers feature full-length adjustment, while the rear utilizes a threaded spacer adjustment. To adjust ride height:

• Loosen the lock nuts on the coilover body.
• Rotate the lower bracket (front) or threaded spacer (rear) to raise or lower the vehicle.
• Ensure equal adjustments on both sides of the vehicle to maintain balance.
• Tighten the lock nuts securely after adjustment.
• Recommended lowering amount for this model: Front -50~-25mm, Rear -45~-30mm.

4.2 Damping Force Adjustment

Both front and rear coilovers feature 40-step damping force adjustment. This allows you to fine-tune the stiffness of the suspension.

• Locate the damping adjustment dial at the top of the shock absorber shaft (or bottom, depending on design).
• Rotate the dial to select your desired damping setting. Typically, '1' is the softest and '40' is the hardest.
• No special tools are required for this adjustment, thanks to the knurled dial.
• Experiment with different settings to find the optimal balance between comfort and performance for your driving style and road conditions.

Figure 4: Damping force adjustment mechanism and graph illustrating the range of adjustment.

Figure 5: Detailed view of the CPRV system and the robust stainless steel lock nut.

5. Maintenance

Regular maintenance ensures the longevity and optimal performance of your CUSCO Street ZERO A Coilover Kit.

• Regular Cleaning: Periodically clean the coilover bodies, especially the threaded sections, to remove dirt, salt, and debris. This helps prevent corrosion and ensures smooth height adjustments.
• Inspection: Regularly inspect the coilovers for any signs of damage, leaks, or loose components. Check the condition of rubber boots and bushings.
• Torque Check: After initial installation and periodically thereafter (e.g., every 5,000 km or 3 months), re-check the torque of all mounting bolts and lock nuts to ensure they are securely fastened.
• Rust Prevention: While the adjustment threads are nickel-chrome plated for protection, applying a thin layer of anti-corrosion grease to exposed threads can provide additional protection, especially in harsh environments.

6. Troubleshooting

This section provides general guidance for common issues. For complex problems, consult a professional mechanic.

6.1 Abnormal Noises (Clunking, Squeaking)

• Loose Bolts: Check all mounting bolts and lock nuts for proper torque.
• Component Contact: Inspect for any parts of the suspension or vehicle body making contact during compression or rebound.
• Worn Bushings: Check the condition of all bushings.

6.2 Uneven Ride Height

• Incorrect Adjustment: Re-measure and adjust the ride height on all four corners, ensuring consistency.
• Spring Sag: While rare for new components, inspect springs for any signs of fatigue or damage.

6.3 Poor Ride Quality / Handling

• Damping Settings: Adjust damping force. If the ride is too harsh, try softer settings. If it feels too bouncy or uncontrolled, try harder settings.
• Tire Pressure: Ensure tire pressures are set correctly.
• Wheel Alignment: An incorrect wheel alignment can significantly impact handling. Have a professional alignment performed.

7. Specifications

8. Warranty

The CUSCO Street ZERO A Coilover Kit comes with a reliable warranty of 1 year or 10,000 km, whichever comes first. This warranty covers manufacturing defects and ensures peace of mind regarding the product's quality and durability. Please retain your proof of purchase for warranty claims. User registration may be required to activate the warranty.

9. Support and Contact

For technical assistance, installation inquiries, or warranty claims, please contact CUSCO customer support or visit the official CUSCO website. Always refer to your specific product model number (619-62N-CB) when seeking support.

Before purchasing, it is crucial to confirm vehicle compatibility on the manufacturer's homepage using your vehicle's model, engine type, drive system, year, and grade information from your vehicle inspection certificate or caution plate.

Official CUSCO Website: www.cusco.co.jp