Spl Suspension Parts For 240sx: Product Review

The Nissan 240SX, particularly the S13 and S14 chassis, enjoys legendary status in the drifting and performance driving world. Its lightweight construction, rear-wheel-drive layout, and relatively simple mechanics make it an ideal platform for modification. Central to unlocking the 240SX's potential is a well-sorted suspension system, and SPL Parts has carved out a significant niche in this market with its high-quality aftermarket components. This in-depth review will delve into the engineering behind some of SPL's most popular 240SX offerings, exploring their design, materials, and how they contribute to improved handling and adjustability.

Understanding the Importance of Suspension Upgrades

Before examining specific SPL Parts, it's crucial to understand why upgrading the suspension is so vital for a 240SX. The factory suspension, while adequate for daily driving, lacks the robustness and adjustability required for competitive motorsports. The primary goals of suspension upgrades are to:

Reduce body roll: Minimize lean during cornering, improving stability and driver confidence.
Increase grip: Maximize tire contact with the road surface, resulting in better acceleration, braking, and cornering speeds.
Improve adjustability: Allow for fine-tuning of suspension parameters to suit different driving styles and track conditions.
Enhance durability: Replace worn or weak components with stronger, more reliable parts.

SPL Parts address these areas through meticulously designed components, often incorporating features not found in the OEM setup. Their focus on quality materials and precise manufacturing ensures long-lasting performance under demanding conditions.

SPL Parts Product Review: Arms and Links

SPL offers a comprehensive range of suspension arms and links for the 240SX, each designed to address specific shortcomings of the factory setup. Let's examine some key products:

Rear Upper Control Arms (RUCA)

The rear upper control arms (RUCAs) play a crucial role in adjusting rear camber. The factory RUCAs offer limited adjustability, making it difficult to dial in the desired camber settings, especially when lowering the car. SPL's RUCAs address this limitation with:

Extended Adjustment Range: Precision-machined adjusters allow for a wider range of camber adjustments, enabling optimized tire contact patch for improved grip.
High-Strength Construction: Typically constructed from lightweight but strong materials like 6061-T6 aluminum or chromoly steel, ensuring durability under high stress.
Spherical Bearings: Replacing the factory rubber bushings with spherical bearings (often referred to as "pillow ball" joints) eliminates bushing deflection under load. This significantly improves suspension response and reduces unwanted toe changes during cornering, known as bump steer. The downside is increased NVH (noise, vibration, and harshness).

The use of spherical bearings is a key differentiator for SPL Parts. While rubber bushings provide some damping and compliance, they also introduce unwanted flex. Spherical bearings offer virtually zero deflection, resulting in a more direct and precise feel.

Traction Rods

Traction rods (also called tension rods) control the fore-aft movement of the rear suspension. The factory traction rods are often weak and prone to deflection, especially under hard acceleration and braking. SPL's traction rods offer improvements in:

Strength and Rigidity: Constructed from high-strength materials like chromoly steel, providing significantly increased resistance to bending and deflection.
Adjustability: Allow for adjusting wheelbase and anti-squat characteristics, influencing traction and handling.
Spherical Bearings: Similar to RUCAs, spherical bearings eliminate bushing deflection, improving suspension response and reducing wheel hop.

By minimizing deflection in the traction rods, SPL Parts help maintain consistent rear suspension geometry, leading to improved traction and stability, particularly during acceleration and braking.

Toe Rods

Toe rods control the rear toe angle, a critical factor in handling and stability. Similar to the other arms, SPL's toe rods provide:

Increased Adjustability: Allow for precise toe adjustments, enabling optimized handling characteristics for different driving conditions.
Robust Construction: Built from high-strength materials to withstand the stresses of aggressive driving.
Spherical Bearings: Eliminating bushing deflection for improved responsiveness and reduced bump steer.

Proper toe alignment is crucial for both straight-line stability and cornering performance. SPL's toe rods provide the necessary adjustability and rigidity to maintain the desired toe settings under load.

Front Upper Control Arms (FUCA)

Front Upper Control Arms, or FUCA's, for the 240SX are a common modification, especially when lowering the vehicle. Dropping the ride height changes the suspension geometry, and the FUCA allows for adjustments to correct camber and caster. SPL offers FUCA's with similar features as their rear counterparts:

Camber and Caster Adjustment: The main benefit here is the ability to independently adjust camber and caster to fine tune handling characteristics.
Spherical Bearings: Once again, these replace the rubber bushings for more immediate response and feedback.
Strength: Constructed from strong materials like billet aluminum or steel, designed to withstand high forces from cornering and impacts.

It's important to note that some FUCA designs may require modifications to the strut tower for proper clearance, so research is important prior to installation.

Materials and Manufacturing

SPL Parts are renowned for their use of high-quality materials and meticulous manufacturing processes. Common materials include:

6061-T6 Aluminum: Lightweight and strong aluminum alloy, often used for arms and brackets.
Chromoly Steel (4130): High-strength steel alloy, used for components subjected to high stresses, such as traction rods and tie rods.
Spherical Bearings: Precision-engineered bearings with hardened steel races and PTFE liners for smooth, low-friction operation. Typically sourced from reputable manufacturers.

Manufacturing processes often involve CNC machining, TIG welding, and precise assembly. These processes ensure consistent quality and dimensional accuracy, which is crucial for proper fitment and performance. Attention to detail is evident in the design of adjustment mechanisms, which are typically robust and easy to use. Threads are clean and precise, and locking mechanisms are secure.

Installation Considerations

Installing SPL Parts typically requires a good understanding of suspension geometry and alignment procedures. While some components may be relatively straightforward to install, others may require specialized tools and techniques. It is highly recommended to consult with a qualified mechanic or suspension specialist for installation and alignment. Proper alignment is essential after installing any suspension components to ensure optimal handling and tire wear. This includes setting camber, caster, and toe angles to the desired specifications.

Potential Drawbacks

While SPL Parts offer significant performance benefits, there are potential drawbacks to consider:

Increased NVH: The use of spherical bearings can transmit more road noise and vibrations into the cabin. This is a trade-off for improved suspension response.
Cost: SPL Parts are generally more expensive than OEM or other aftermarket options. However, the higher price reflects the superior materials, design, and manufacturing quality.
Maintenance: Spherical bearings may require occasional lubrication or replacement, depending on usage and environmental conditions.

Conclusion

SPL Suspension Parts represent a significant upgrade for the Nissan 240SX, offering improved handling, adjustability, and durability. Their meticulous design, high-quality materials, and precise manufacturing processes set them apart from many other aftermarket options. While there are potential drawbacks to consider, the performance benefits often outweigh the disadvantages, particularly for those seeking to maximize the potential of their 240SX for motorsports or spirited driving. Ultimately, the decision to invest in SPL Parts depends on individual needs and budget. However, for those seeking a top-tier suspension solution, SPL Parts are a worthwhile consideration. Just remember to do your research, understand the implications of each modification, and ensure proper installation and alignment to reap the full benefits of these high-performance components.

Investing in quality suspension components like those offered by SPL Parts is an investment in the overall performance and enjoyment of your 240SX.