High-performance RB-series engines demand more oil volume and pressure stability than the factory oil pump was designed to deliver. The Tomei High Volume Oil Pump (part number TB203A-NS05A) is an oversized unit engineered for the Nissan RB26DETT, RB25DET, and RB20DET platforms, providing a significant increase in flow capacity for street, circuit, and high-boost applications.
Compared with the stock pump, the Tomei unit features a larger 97.5 mm outer gear diameter and a three-piece gear set manufactured from high-strength SCM435 material rather than sintered alloy. This combination produces approximately 56 liters per minute at 6,000 rpm—noticeably higher than the factory flow rate—while improving durability under elevated RPM and load. The gear cover is also thicker and secured with additional bolts, enhancing rigidity and sealing to reduce the risk of leaks or distortion at higher pressures. Pressure can be fine-tuned using the included spring and shim options to suit specific engine builds.
For engines running higher boost, aggressive camshafts, or extended high-RPM operation, adequate oil supply is critical to bearing and valvetrain longevity. The Tomei High Volume Oil Pump addresses this requirement with a robust, purpose-built design. At Terra Firma Automotive, we supply this genuine Tomei oversized oil pump as a key supporting upgrade for serious RB builds. Whether you are assembling a refreshed engine or preparing a high-output turbo setup, this pump delivers the increased flow and strength expected from Tomei’s Japanese engineering. Choose Terra Firma Automotive for authentic components that support reliable lubrication under demanding conditions.
- Genuine Tomei High Volume / Oversized Oil Pump
- Part Number: TB203A-NS05A
- Application: Nissan RB26DETT / RB25DET / RB20DET
- Flow rate: approximately 56.0 L/min at 6,000 rpm
- Gear material: high-strength SCM435
- Three-piece gear design (vs stock two-piece)
- Outer gear diameter: 97.5 mm (larger than stock)
- Thicker gear cover with additional fasteners
- Improved sealing and structural rigidity
- Adjustable oil pressure via springs and shims
- Supports higher RPM and elevated engine loads
- Helps maintain oil pressure under demanding conditions
- Direct upgrade for RB-series engines
- Trusted Japanese performance component
- Available from Terra Firma Automotive
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