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Fuel Injection / Collection Rail
- Porsche 911 1978-1983 3.0L / SC
- Porsche 911 1984-1986 3.2L
- Porsche 911 1987-1989 3.2L G50
- Porsche 911 1978-1989 3.3L Turbo (930)
- Porsche 964 (911) C2 1989-93
- Porsche 964 (911) C4 1989-93
- Porsche 964 (911) RS 3.6L 1991-93
- Porsche 964 (911) RS 3.8L 1991-93
- Porsche 964 (911) TURBO 3.3L 1991-93
- Porsche 964 (911) TURBO 3.6L 1991-93
- Porsche 993 (911) C2 1994-97
- Porsche 993 (911) C4 1994-97
- Porsche 993 (911) RS 1994-97
- Porsche 993 (911) C2S 1994-97
- Porsche 993 (911) C4S 1994-97
- Porsche 993 (911) TURBO 1994-96
- Porsche 993 (911) GT2 1994-97
- Porsche 993 (911) TURBO S 1994-97
- Porsche 924S 2.5L 1986-87
- Porsche 924S 2.5L 1988
- Porsche 944 2.5L 8V 1982-87
- Porsche 944 2.7L 8V 1988-89
- Porsche 944S 2.5L 16V 1987-88
- Porsche 944S2 3.0L 16V 1989-91
- Porsche 944 Turbo 2.5L 8V 1985-88
- Porsche 944 Turbo 2.5L 8V 1989-91
- Porsche 944 Turbo S 2.5L 8V 1988
- Porsche 968 3.0L 1992-94
- Porsche 968 Sport 3.0L 1994-95
- Porsche 968 CS 3.0L 1993-95
- Porsche 968 Turbo S 3.0L 1993-94
- Porsche 928 4.5L 1978-82
- Porsche 928S 4.7L 1981-83
- Porsche 928S2 4.7L 1984-86
- Porsche 928S4 5.0L 1987-92
- Porsche 928GT 5.0L 1989-91
- Porsche 928GTS 5.4L 1992-95
Domed Cap Nut – Fuel Pump & Fuel Rail Fixing M12 x 15,5
High-quality domed cap nut designed for securing components within the Porsche fuel system, including the fuel pump and fuel rail assemblies.
Used across a wide range of models including Porsche 924S,
944, 968, 928, and 964, this cap nut provides a secure fastening solution while
protecting exposed threads with its domed design. It plays an important role in
maintaining the integrity and safety of fuel system connections.
Fits:
- Porsche 911 1978-1983 3.0L / SC
- Porsche 911 1984-1986 3.2L
- Porsche 911 1987-1989 3.2L G50
- Porsche 911 1978-1989 3.3L Turbo (930)
- Porsche 964 (911) C2 1989-93
- Porsche 964 (911) C4 1989-93
- Porsche 964 (911) RS 3.6L 1991-93
- Porsche 964 (911) RS 3.8L 1991-93
- Porsche 964 (911) TURBO 3.3L 1991-93
- Porsche 964 (911) TURBO 3.6L 1991-93
- Porsche 993 (911) C2 1994-97
- Porsche 993 (911) C4 1994-97
- Porsche 993 (911) RS 1994-97
- Porsche 993 (911) C2S 1994-97
- Porsche 993 (911) C4S 1994-97
- Porsche 993 (911) TURBO 1994-96
- Porsche 993 (911) GT2 1994-97
- Porsche 993 (911) TURBO S 1994-97
- Porsche 924S 2.5L 1986-87
- Porsche 924S 2.5L 1988
- Porsche 944 2.5L 8V 1982-87
- Porsche 944 2.7L 8V 1988-89
- Porsche 944S 2.5L 16V 1987-88
- Porsche 944S2 3.0L 16V 1989-91
- Porsche 944 Turbo 2.5L 8V 1985-88
- Porsche 944 Turbo 2.5L 8V 1989-91
- Porsche 944 Turbo S 2.5L 8V 1988
- Porsche 968 3.0L 1992-94
- Porsche 968 Sport 3.0L 1994-95
- Porsche 968 CS 3.0L 1993-95
- Porsche 968 Turbo S 3.0L 1993-94
- Porsche 928 4.5L 1978-82
- Porsche 928S 4.7L 1981-83
- Porsche 928S2 4.7L 1984-86
- Porsche 928S4 5.0L 1987-92
- Porsche 928GT 5.0L 1989-91
- Porsche 928GTS 5.4L 1992-95
Diagram ref no 38
Manufactured to OEM specifications, this component ensures precise fitment, corrosion resistance, and long-term durability—making it ideal for maintenance, repair, or restoration work.
Reference Number: 92811047505
Key Features
• Domed cap nut for fuel system applications
• Used on fuel pump and fuel rail assemblies
• Suitable for multiple Porsche models
• Protects threads while securing components
• OEM-style fit and finish
• Durable, corrosion-resistant construction
Function and Purpose
This cap nut is a key fastening component within the fuel system.
It helps to:
• Secure fuel pump and fuel rail components
• Protect threaded studs from damage and corrosion
• Maintain safe and stable fuel system assembly
• Ensure proper sealing and fastening integrity
Why Replace Cap Nuts
Over time, hardware components can degrade or become damaged.
Common issues include:
• Corrosion or rust
• Rounded or damaged threads
• Loss of proper torque retention
• Compromised fastening security
Replacing worn hardware ensures reliable and safe system assembly.
Related reference numbers
Related, superseded, cross reference or alternative numbers for comparison.
92811047505
The product you are viewing cross references to these numbers
Fuel Injection Rails & Components – Precision Fuel Delivery for Peak Porsche Performance
The fuel injection rail (or fuel collection rail) and related components are essential to maintaining consistent fuel delivery and pressure in your Porsche’s high-performance engine. The fuel rail distributes fuel evenly to the injectors, ensuring precise combustion and smooth throttle response under all driving conditions.
At Design911, we stock a comprehensive range of precision-engineered fuel injection rails, fittings, and components built to manufacturer-quality standards for performance, reliability, and longevity. Each part is crafted from high-grade aluminium, stainless steel, or reinforced composites, designed to resist corrosion, heat, and vibration — delivering reliable performance whether you’re maintaining a classic Porsche or fine-tuning a modern GT model.
Our selection includes fuel rails, connectors, injectors, regulators, and sealing hardware — everything needed to keep your Porsche’s fuel injection system performing flawlessly.
What Do Fuel Injection Rails & Parts Do?
Fuel injection rails and components ensure your Porsche’s engine receives the right amount of fuel at the right time. Working together, they maintain stable pressure and evenly distribute fuel to each injector for efficient combustion and power output.
Core Functions:
- Fuel Rail: Channels fuel evenly to the injectors under constant pressure.
- Fittings and Connectors: Securely seal and link the rail, pump, and injectors.
- Regulators & Sensors: Maintain optimal fuel pressure and monitor delivery consistency.
- Seals & Gaskets: Prevent fuel leaks and pressure loss across components.
A balanced, clean, and well-functioning injection system ensures smooth acceleration, optimal efficiency, and reduced emissions — crucial for Porsche performance.
Why Do Fuel Injection Components Fail?
Fuel injection parts operate under high pressure and heat, meaning even small imperfections can affect performance. Over time, wear, contamination, and corrosion can lead to inconsistent fuel delivery or leaks.
Common Causes of Failure Include:
- Corrosion from moisture or fuel impurities.
- Clogged injectors or blocked fuel rails due to sediment buildup.
- Cracked fittings or deteriorated seals, leading to leaks.
- Worn pressure regulators, causing fuel pressure imbalance.
- Fuel contamination from dirty filters or ageing fuel tanks.
Symptoms of failure include rough idling, loss of power, poor fuel economy, or hard starting, often traced to worn or restricted fuel system components.
Why Replace with Precision-Engineered Fuel Injection Parts?
Upgrading or replacing worn fuel injection rails and components restores your Porsche’s performance, responsiveness, and reliability. Precision-fit, high-strength replacements ensure smooth pressure regulation, clean fuel delivery, and efficient combustion.
Key Benefits:
- Restores accurate and consistent fuel delivery.
- Improves throttle response and engine smoothness.
- Prevents leaks and pressure fluctuations.
- Reduces fuel consumption and emissions.
- Crafted from durable, corrosion-resistant materials.
- Direct-fit compatibility for Porsche classic and modern models.
Whether performing a rebuild or upgrading for track use, high-quality injection components are essential for maintaining Porsche precision and performance.
Highlights:
- Complete range of Porsche fuel rails, injectors, and fittings.
- Precision-machined for accurate fuel delivery and sealing.
- Engineered from lightweight, high-strength alloys.
- Compatible with classic and modern Porsche injection systems.
- Ensures reliable pressure regulation and clean fuel flow.
- Perfect for rebuilds, restorations, or performance upgrades.