High quality designed springs is required to transfer the exact movement of the camshaft to the valves at high engine speeds on high performance engines. The 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. We spend time and money to help you save your valuable time and money.
|R33RB25DE(T)||A||～8.80||13203R855||432.68（TAX inc 466）|
|B||～10.25||163022||648.09（TAX inc 698.00）||・With Intake side retainers
・For solid conversions
FEATURE / SPEC
|DIA METER||FREE LENGTH(mm)||SET LENGTH(mm)||LIFT LENGTH(mm)||COMPRESSED LENGTH(mm)||SET LOAD(kgf)||LIFT LOAD(kgf)||MATERIAL||PROCESS||COLOR ID|
|A TYPE IN||Φ3.80||36.2||30.6||21.6||19.0||23.9||62.4±5%||SWOSC-V||Nitride||Green|
|A TYPE EX||Φ3.90||41.0||34.4||25.6||24.0||25.6±7%||72.1±7%||SWOSC-VX||Nitride||Blue|
|B TYPE (IN/EX)||Φ3.90||41.0||35.0||25.0||24.0||24.2±7%||80.6±7%||SWOSC-VX||Nitride||Blue|
■ 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.
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.
High lift camshaft could not be used for ECR33 RB25DET because NVCS oil pipe is running beneath the valve spring and it restricts the amount of the intake valve lift. Neither, could strengthen valve spring have been manufactured according to its construction.
Now, we developed RB25DET special intake valve retainer that enables corresponding to high lift camshaft by 10.25mm, by enlarging the amount of valve lift. Deceleration of the valve can be also secured by applying strengthen valve spring, which is required for the high lift camshaft and high rotation of the engine.
The Phenomenon which material of the valve spring resonance and causes the spring itself to vibrate violently.
The Phenomenon that the valve rallies to the cam surface instead of settled back. It happens when the valve cannot follow the camshaft rotation and lifted irregally.
The Phenomenon that the valve is bouncing repeatedly from valve seat other than sticking to it when it is closing.
Breakage that occurs during the repeat operation of the spring. (The larger lift, the more possibilities to get fatigued)
The Phenomenon in which the load (free play) of a spring decreases while inuse. It is related to the maximum stress under operation and use time.