Tomei Racing Double Valve Spring Kit- Nissan SR20DET.

High quality designed springs are required to transfer the exact movement of the camshaft to the valves at high engine speeds on high performance engines. Tomei products are always engineered with precision in mind to suit the user’s needs. So with this in mind careful choices in material selection is made with surface coating and other technologies. Then the pre-production products are put through an extensive testing program for checking durability, quality and performance. Tomei have spent a lot of time and money to help you save your valuable time and money. Multi Coil Unequal Pitch Springs By combining several steps of spring rates into the one spring and vibration frequency becomes amazingly high. This greatly minimizes resonance and the chances of surging.  Advanced Oil Tempered Chromium-silicone Alloy Steel Core Oil tempered chromium-silicone alloy steel wire is used which is considered to be the best material for springs for performance applications and evolved it even further. Combined with a new optimized design, not only did we make it tougher, we also succeeded in suppressing valve jumps or bounce even when raising the engines speeds RPM limit. Shot Peening A process that strikes many small steel balls onto the surface of the spring at high speeds is made to enhance the surface of the spring to raise its fatigue limit. Although it has been carried out earlier during the manufacturing process. Warm Setting The process that is adding higher loads beyond the actual limits to the highly heated spring. This will modify its shape and keep it permanently fixed. We succeeded in securing the highest performance over a long period of time while preventing sagging. Nitriding The surface treatment method for making nitrogen permeates the spring and gives it large surface compression repulsion. This method was chosen to raise the fatigue limit to suit the demands or running high lift camshafts. The dangers of spring failure is greatly reduced with the 1.5 times increase in the springs fatigue limit with the combined use of Oil tempered chromium-silicone alloy steel wire and Nitriding. This is how our valve springs are suitable for use on extreme engine speed conditions of super-high revs exceeding 10,000 RPM which had not been previously possible with high lift camshafts.