The RA304A-NS05B is a high-performance valve spring set designed by Real Speed Engineering (R.S.E.) to support high cam lift and racing applications, particularly for high-RPM engines. It is crafted with advanced materials and optimized to prevent valve float, bounce, fatigue, and surging during high-performance operations.

✅ Key Features and Highlights

1. Advanced Oil-Tempered Chrome-Silicone Alloy Core

• Enhanced silicon-chromium alloy, further improved through advanced manufacturing processes.

• Reduces valve jump and bounce during high-RPM operation, enabling a higher RPM range.

• Increases fatigue limit to ensure longevity under extreme conditions.

2. Variable Stage Unequal Pitch Springs

• Incorporates multi-stage spring rates within a single spring to increase the natural frequency.

• Effectively reduces resonance and minimizes the risk of surging.

• Unequal pitch design improves spring response and prevents harmful oscillations.

3. Nitriding Treatment for Durability

• Surface treated with nitrogen to improve strength and resistance to stress fatigue.

• Essential for coping with the high demands of high-lift camshafts.

• Ensures prolonged lifespan under rigorous conditions.

4. Shot Peening for Stress Relief

• Small steel balls are shot at high speed onto the spring surface to introduce residual compressive stress.

• This process increases the fatigue limit and enhances the overall durability of the valve springs.

5. Hot Setting for Shape Retention

• Springs are subjected to high-temperature stress beyond their operating load to prevent permanent deformation.

• Prevents "fading," ensuring the springs maintain their performance characteristics over time.

6. Oval Core Wire Technology (Specific to High Lift Cams)

• The oval-shaped wire cross-section allows for shorter coil lengths and accommodates high lift camshafts.

• Enhances spring flexibility and reduces coil binding during operation.

📦 Application and Compatibility

• Compatible Engines:

  • RB26DETT (Type B Configuration)

• Lift Compatibility:

  • Intake: Up to 12.30mm

  • Exhaust: Up to 11.33mm

  • Designed for camshafts with a base circle of Φ30mm, requiring the use of R.S.E. valve lifters.