Performance Modification Hierarchy For Nissan 240sx

The Nissan 240SX, particularly the S13 and S14 chassis, enjoys an almost legendary status in the automotive world, particularly amongst enthusiasts of drifting, time attack, and overall performance modification. Its lightweight design, rear-wheel-drive configuration, and relatively affordable price point made it the perfect platform for aspiring and seasoned tuners alike. However, the sheer volume of aftermarket parts and potential upgrades can be overwhelming. To avoid wasting time and money, it's crucial to follow a well-defined performance modification hierarchy. This article outlines a logical progression of upgrades for your 240SX, maximizing bang for your buck and ensuring a well-rounded, reliable performance machine.

Phase 1: Reliability and Maintenance - The Foundation

Before even thinking about horsepower gains or improved handling, the first step is to ensure your 240SX is mechanically sound. These cars are getting older, and neglecting basic maintenance is a recipe for disaster, especially when adding performance parts. This phase focuses on addressing potential weak points and establishing a solid foundation for future modifications. This is where you should be pouring your initial investment, if the car is new to you.

Essential Maintenance Items:

Full Fluid Flush: Engine oil, coolant, brake fluid, power steering fluid, transmission fluid, and differential fluid. Use high-quality synthetic fluids where appropriate.
Timing Chain/Belt Replacement: If you don't have proof that it was recently done, replace it. A snapped timing chain/belt can cause catastrophic engine damage.
Spark Plugs and Wires (or Coil Packs): Ensure proper ignition for optimal performance and fuel economy.
Fuel Filter: Replace to ensure a clean fuel supply. A clogged filter can lead to poor performance and potential fuel pump damage.
Air Filter: A clean air filter allows for proper airflow into the engine.
Inspect and Replace Hoses and Belts: Check for cracks, wear, or leaks and replace as needed. Old, brittle hoses are prone to bursting.
Check and Replace Bushings: Worn bushings negatively affect handling and can cause clunking noises. Common culprits are control arm bushings, sway bar bushings, and differential bushings. Polyurethane bushings offer improved durability and handling but can increase NVH (noise, vibration, and harshness).
Brake System Inspection: Check brake pads, rotors, calipers, and brake lines. Replace worn components. Consider upgrading to stainless steel brake lines for improved brake feel.
Tire Condition: Ensure tires have adequate tread and are properly inflated. Properly inflated tires provide the best grip and handling.

Addressing Common 240SX Issues:

KA24DE Headgasket: The KA24DE engine (found in early 240SX models) is known for headgasket issues. Consider preventative replacement with a stronger aftermarket gasket, especially if planning for forced induction later.
Rust Repair: These cars are prone to rust, especially in areas like the frame rails, rocker panels, and floorboards. Address any rust issues promptly to prevent further damage.
Wiring Harness Inspection: Check for cracked or frayed wiring, especially around the engine bay and ECU. Replace or repair as needed.

Ignoring these initial steps is setting yourself up for expensive repairs down the line. A reliable car is a fast car.

Phase 2: Suspension and Handling - Cornering Confidence

Once the car is mechanically sound, focus on improving handling. The 240SX is a naturally well-balanced car, but the aging factory suspension components can significantly hinder its potential. Upgrading the suspension will provide more grip, reduce body roll, and improve overall handling characteristics. This phase will make the biggest seat-of-the-pants difference for the average driver.

Recommended Suspension Upgrades:

Coilovers: Coilovers offer adjustable ride height and dampening, allowing you to fine-tune the suspension for your specific needs. Choose a quality set from a reputable brand.
Sway Bars: Upgraded sway bars reduce body roll during cornering, improving stability and handling.
Adjustable Tension Rods: Allow for precise adjustment of caster, improving steering feel and stability.
Rear Upper Control Arms (RUCA): Correct camber after lowering the vehicle, ensuring proper tire wear and maximizing grip.
Rear Toe Arms: Allow for precise adjustment of toe, which affects stability and handling.
Subframe Collars: Stiffen the rear subframe, reducing unwanted movement and improving handling response.

Consider an alignment after each suspension change for optimum performance.

Remember, a well-sorted suspension will allow you to carry more speed through corners and maintain better control.

Phase 3: Brakes - Stopping Power and Control

Improving braking performance is crucial for both safety and performance. Upgrading the brakes will provide increased stopping power, reduced brake fade, and improved pedal feel. You don't want to outdrive your brakes!

Recommended Brake Upgrades:

Performance Brake Pads: High-performance brake pads offer increased friction and resistance to brake fade. Choose pads appropriate for your driving style and track conditions.
Slotted or Drilled Rotors: While debatable for street use, slotted or drilled rotors can help dissipate heat and improve braking performance, especially in track environments. However, avoid cheap drilled rotors, as they can be prone to cracking.
Stainless Steel Brake Lines: Stainless steel brake lines reduce brake line expansion under pressure, resulting in a firmer pedal feel and more consistent braking performance.
Brake Master Cylinder Brace: A brake master cylinder brace stiffens the firewall around the master cylinder, reducing flex and improving pedal feel.
Big Brake Kit (BBK): A big brake kit provides significantly increased braking performance with larger rotors and multi-piston calipers. This is a more expensive upgrade but offers a substantial improvement in stopping power.

Phase 4: Engine Modifications - Adding Horsepower

Now that the car handles and stops well, it's time to focus on increasing horsepower. However, it's important to approach engine modifications strategically to avoid reliability issues and ensure optimal performance.

Stage 1: Bolt-On Upgrades

These modifications are relatively simple to install and offer modest horsepower gains.

Cold Air Intake (CAI): A cold air intake replaces the restrictive factory airbox with a less restrictive system, allowing for increased airflow to the engine.
Performance Exhaust System: A performance exhaust system improves exhaust flow, reducing backpressure and increasing horsepower. Consider a cat-back exhaust system or a full turbo-back system (if applicable).
Headers (if applicable): Aftermarket headers offer improved exhaust flow compared to the factory manifolds.
ECU Tune: An ECU tune optimizes the engine's air-fuel ratio and timing for increased horsepower and torque. This is essential after installing bolt-on modifications to maximize their potential.

Stage 2: Internal Engine Modifications

These modifications require more extensive engine work and offer more significant horsepower gains.

Cams A camshaft is a rotating shaft containing pointed cams which operate the inlet and exhaust valves of an engine.
High Compression Pistons: Increase the compression ratio for more power.
Ported and Polished Cylinder Head: Improves airflow through the cylinder head.
Upgraded Fuel Injectors: Provide sufficient fuel for increased horsepower.
Fuel Pump: Ensure adequate fuel supply to the injectors.

Stage 3: Forced Induction (Turbocharging or Supercharging)

Forced induction is the most effective way to significantly increase horsepower. However, it also requires the most extensive modifications and can be the most expensive.

Turbocharger Kit: A turbocharger kit includes all the necessary components for turbocharging your 240SX, including the turbocharger, exhaust manifold, intercooler, piping, and boost controller.
Supercharger Kit: A supercharger kit offers an alternative to turbocharging, providing instant boost response.
Reinforced Engine Internals: Forced induction puts significant stress on the engine. It is highly recommended to upgrade the engine internals (pistons, connecting rods, crankshaft) to handle the increased power.
Standalone ECU: A standalone ECU offers the most precise control over the engine's parameters, allowing for optimal performance and reliability with forced induction.

Phase 5: Drivetrain - Putting the Power Down

As you increase horsepower, it's crucial to upgrade the drivetrain to handle the added power and prevent premature failure. The stock 240SX drivetrain is not designed for high horsepower levels.

Recommended Drivetrain Upgrades:

Performance Clutch: A performance clutch offers increased clamping force to prevent slippage with increased horsepower.
Lightweight Flywheel: A lightweight flywheel improves engine response and acceleration.
Upgraded Transmission: The stock transmission can be a weak point at higher horsepower levels. Consider upgrading to a stronger transmission, such as a CD009 from a Nissan 350Z.
Limited Slip Differential (LSD): An LSD improves traction by distributing power evenly to both rear wheels, preventing wheel spin.
Upgraded Axles: Upgraded axles are stronger than the stock axles and can handle the increased power without breaking.

Conclusion

Modifying a Nissan 240SX can be an incredibly rewarding experience. By following this performance modification hierarchy, you can ensure a well-rounded, reliable, and high-performing vehicle. Remember to prioritize reliability and handling before focusing solely on horsepower gains. A well-balanced car that handles and stops well will ultimately be more enjoyable to drive than a high-horsepower car with a weak chassis and braking system. Take your time, do your research, and enjoy the process of transforming your 240SX into your dream machine. Happy building!