technician with protective blue gloves examines fuel injector as part of manufacturing process.
A simple idea with serious emissions and fuel economy returns.

Industry-leading 500+ bar GDi solution sets a new standard for performance. 

No doubt, gasoline direct injection (GDi) engines are a critical element in your propulsion technology strategies. The systems offer clear advantages given the push to achieve tighter fuel economy and emissions mandates.

In 2016, with the unveiling of the industry’s first series production 350-bar system, Delphi Technologies pushed the boundaries of GDi innovation. Once considered unattainable improvements in particulate emissions, durability and fuel pump noise levels were achieved. The higher-pressure system also held the line on costs, while simultaneously introducing upgrades in materials and manufacturability. It was a job well done.

But even as we were rolling out this new direct injection engine technology, we knew more could be gained if we pushed past 350-bar pressures. The biggest challenge? Designing a system that could deliver increased benefits without triggering the need for high-priced engine modifications.

You push the pressures too far and you’re going to outstrip the capabilities of the cam drives on the majority of today’s engines. We knew that unless we solved for this singular issue any new gains in performance would be overshadowed by the price tag attached to powerplant redesigns. 

So, the key questions facing us were:

  • Could we find a way to increase pressure while lightening the load on the engine?
  • Did we think we could do it again – set the next new bar in GDi performance?

The answer to both: Absolutely.

Fast Take: 500+bar GDi – More pressure, more benefits.



The breakthrough.

Welcome to our new 500+ bar GDi system. This industry-leading solution for direct injection gasoline systems allows you to realize the benefits of higher-pressure performance with today’s engine designs. This breakthrough, when compared to 350-bar systems, delivers:

  • Up to a 50 percent improvement in particulate emissions – both in mass (PM) and number (PN) – allowing you to hit post Euro 6d and China 6 emissions standards with simpler after-treatment systems. 
  • Up to a 1 percent reduction in fuel consumption, despite the additional demands placed on the engine.

The system features:

  • A new fuel injector that’s enhanced with an optimized pressure vessel, improved rail interface and a 30 percent increase in magnetic performance that result in enhanced fuel-delivery precision.
  • A new forged fuel rail that’s 25 percent lighter due to material reductions while still managing higher pressures. The rail is more durable and flexible, offering both offset and overhead placement options. We’ve also added in-house rail machining capabilities, which simplifies development and heightens controls.
  • Upgrades to our most advanced engine controller with increased processing power for better fuel delivery with multiple injection modes, as well as tighter closed loop controls.

These advances address higher-pressure challenges such as injector dynamics in order to achieve small pulse repeatability, as well as injector packaging to avoid space constraints.

Material enhancements, simplified component fabrication with reduced welds and fittings, as well as advanced manufacturing techniques are also part of the package to further improve durability and reliability. As with all our GDi technologies, the system is fully compatible with global fuels for quick adaptation to all gasoline engine platforms. And, the system is production ready – today – for integration into GDi platforms.

The secret to the success of the new system, however, rests with a patent-pending invention called a plunger ring seal (PRS), which is a continuous polymer band that’s integral to our next-gen GDi fuel pump. And it’s this seal – an incredibly simple solution to one of the biggest problems with higher-pressure GDi systems – that makes it all possible.

A chart showing the gain in fuel economy and emissions performance with 500+bar GDi technologies.

Put a ring on it.

Enter the PRS. This special polymer seal is integrated with the plunger, virtually eliminating the leak path between the plunger and the sleeve in which it rides. It allows the pump to come up to pressure right at the start and maintain pressure at low RPMs – both critical for fuel economy and emissions gains. 

Better, it comes up to pressure without the higher cam load and engine modifications associated with increasing plunger size. In fact, with the PRS, you can move to smaller plungers so that the loads are now reduced up to 30 percent. Smaller plungers can lower cam stresses and reduce drive torque.

Simple, elegant in its design, the PRS enables the pump to deliver:

  • Up to a 40 percent improvement in overall efficiency at lower RPMs.
  • A 23 percent reduction in the time it takes to hit operating pressures at typical starting speeds and RPMs.

It’s heat and fuel resistant, self-lubricating and validated to 3,000 hours of cycle testing. It also features a redesigned pressure relief valve, and upgrades to the interface structures of both the inlet valve and outlet fitting to the pump body for better durability and performance.

Finally, the PRS is compatible for use on our 350-bar GDi systems. It can deliver quicker engine starts, the potential for reduced plunger sizes on current applications, as well as improvements in fuel economy and emissions performance with existing programs.

An illustration showing the internal design improvements made to a gasoline direct injection fuel pump.

What’s next.

The 500+ bar system is production ready and expected to premier on 2022 or 2023 model year vehicles. We’re also continuing to expand our GDi service program with tools, training and more to ensure dealers and independent repair shops have what’s needed to service advancing GDi systems. Visit our aftermarket site to keep up with our growing GDi service offering.