Tomei Main Bolt Kit - Subaru EJ20 / EJ25SKU: 193113
Tomei main stud kits offer much higher stength over factory bolts allowing more boost and higher power levels.
The crank bearing cap is needed to secure strict metal clearance of the crankshaft by fixing bearing firmly at the time of high rotation and high load, enduring the force from bend or torsion vibration. However, in combination with a common bolt and nut, no matter what strength bolt is used, bolting power concentrates on from third mountains to the 1st mountain of the screw, and the total bolting power cannot be increased beyond a certain value. Moreover, excessive stress is concentrated and may damage the bolt. Stud bolt, on the other hand, is applied dynamic design to its threading so that the bolting force is dispersed to all the threads and higher bolting power is generated.