Powertrain Systems

Delphi Multi-Port Fuel Injection (MPFI) Fuel Rails are integrated, pre-assembled conduits that transfer fuel from a vehicle's chassis fuel line and distribute it to each fuel injector location at the engine. Delphi offers a variety of MPFI Fuel Rails in both stainless steel and composite material designs to provide manufacturers with a choice of efficient packaging, superior performance and durability, low cost, and aesthetics. Pressure damping options include:

• Undamped ("Tech 0") Fuel Rails in both stainless steel and composite material designs that provide a low cost option for applications without fuel distribution issues.
• Internally Damped ("Tech 1") Fuel Rails, also available in both stainless steel and composite material designs, feature a stainless steel damper positioned inside the fuel rail conduit directly over the injectors. The damper is robust to thermal and flexible fuel environments. Pulsations are dampened at the injector source.
• Integrally Damped ("Tech 2") Fuel Rails are made of stainless steel. The conduit walls act as the damping surface to eliminate the internal damper.

Delphi MPFI Fuel Rails are supplied preassembled with Delphi Multec^® Fuel Injectors and a pressure regulator (if applicable). They are leak tested for elimination of engine-level leak testing. They provide low gain and filtered pressure regulation with a provision for reference manifold pressure to help provide consistent operation over the life of the vehicle. A range of pressure regulation is available.

Delphi Stainless Steel MPFI Fuel Rails provide high resistance to impacts and prevent corrosion with all market fuels. The stainless steel construction and use of a single O-ring at the injector interface contribute to reduced evaporative emissions. Delphi has manufactured stainless steel MPFI fuel rails for more than 25 years.

Delphi Composite Material MPFI Fuel Rails offer enhanced packaging flexibility because of advanced composite molding technology. Their composite material construction also provides reduced heat transfer. Composite fuel rails typically offer 50% lower cost and 50% lower mass than comparable steel fuel rails. No failures due to composite material degradation have been experienced. Delphi has manufactured composite material MPFI Fuel Rails for more than 20 years.

Benefits

• Delphi MPFI Fuel Rails are robust to ethanol fuel blends (0 to E100) and methanol fuel blends (including M15) for 15 years/150,000 miles, based on severe temperature and vibration schedules.
• Excellent warranty performance. Excellent first-time quality. Delphi has never experienced a fuel rail failure due to material degradation.
• Delphi's Internal Damping and Integral Damping designs minimize pulsations. (Low pressure pulsations.)

Typical Applications

Delphi Multi-Port Fuel Injection Fuel Rails are suitable for use on port fuel injection gasoline and flexible fuel engines ranging from one to 12 cylinders. Each MPFI fuel rail is unique and optimized to meet the customer's specific application requirements.

Delphi offers a variety of Multi-Port Fuel Injection Fuel Rails suitable for gasoline and flexible fuel engine applications ranging from one to 12 cylinders.

Fuel Pressure Pulsations at Fuel Rail Inlet Connection

Delphi's MPFI Fuel Rail damping technology can significantly reduce pressure pulsation levels versus undamped fuel rail designs as demonstrated by this graph.

Performance Advantages

Delphi's high volume business and global presence (United States, Mexico, China, Korea, Brazil, Poland and Luxembourg) provide manufacturers with the benefits of a varied customer base and diverse operating environments. And with its extensive experience in fuel rail design and manufacturing, Delphi understands the fuel rail environment and validation requirements. Delphi investigates fuels worldwide and has developed aggressive formulations for ethanol and methanol, and worst case fuel scenarios as required for validation testing.

Delphi conducts all testing in-house using its own laboratories and state-of-the-art tools for fuel rail design (simulation and calculation), testing and validation.

Delphi's MPFI Fuel Rail damping technology can significantly reduce pressure pulsation levels. As a pressure wave travels in a conduit, it locally deflects the Delphi-designed damping surfaces, decreasing pressure pulsations. The reduction of pressure pulsations improves cylinder-to-cylinder fuel distribution, improves pulse-to-pulse fueling control and reduces chassis line vibrations. This technology helps improve drivability, reduce emissions and minimize fuel line noise.

The Delphi Advantage

With extensive experience in engine management systems development, Delphi provides vehicle manufacturers with unique system-level knowledge and analysis capabilities. Delphi has a thorough understanding of automotive markets around the world and a long history of supplying gasoline engine management products throughout the world. Delphi has a global network of resources and is positioned to respond quickly and efficiently with localized component manufacturing facilities and local market calibration expertise. Delphi offers a complete engine management systems product portfolio, including:

• Fuel injection systems
• Ignition systems
• Air and fuel management
• Electronics
• Sensors and actuators
• Valve train systems
• Fuel handling systems
• Evaporative emissions systems