In a paper presented at the 2019 Vienna Motor Symposium, Delphi Technologies revealed a new 500+ bar GDi system that can reduce particulate emissions by up to 50 percent compared to state-of-the-art 350 bar system without expensive engine design modifications. Reducing the number of exhaust gas particulates, including those smaller than 23 nm, will help manufacturers meet increasingly stringent future global emissions standards.
Reducing engine-out emissions cuts tailpipe emissions in the crucial period before catalyst light-off and reduces the need for costly aftertreatment systems. This reduces emissions in regulated testing including RDE (Real Driving Emissions). At the end of 2016, Delphi Technologies entered production with its industry first 350 bar GDi system, which reduces exhaust particulates by up to 70 percent compared with industry-standard 200 bar systems.
“The industry has long recognized that increasing injection pressure to 500+ bar could substantially cut engine-out particulates while improving CO2 emissions and fuel economy,” explains Walter Piock, chief engineer, Gasoline Systems, Delphi Technologies.
The challenge has been to achieve such pressures without increasing the drive loads from the pump. As most engines power the GDI pump through the camshaft drive, a conventional approach would usually require a costly redesign and strengthening of the camshaft mechanism.
“By designing an innovative new internal sealing system for our GFP3 500+ bar pump, in some applications, we have designed a downsized plunger diameter which prevents increasing the loads in the drive mechanism,” reveals Piock.
With the new Delphi Technologies system, engine designers can benefit from 500+ bar injection pressures without having to make costly changes to the majority of existing camshaft drive systems.
With combined demands for improved urban air quality and lower greenhouse gas emissions, the fuel injection system is an important building block for meeting future legislative targets. Delphi Technologies’ 500+ bar system can help vehicle manufacturers meet both challenges.
According to Piock, “Our 350 bar GDi system reduces exhaust particulates by up to 70 percent compared with industry-standard 200 bar systems and we are going one step further with our new 500+ bar GDi system which further reduces these emissions by up to 50 percent compared to the 350 bar system”.
To complete the new 500+ bar system, Delphi Technologies has developed all system components including Multec 16 injectors, pumps, forged rail as well as the appropriate engine control system and software. These components, which further improve durability and reliability, also require no or only minor physical changes to existing engines because they match existing packaging constraints and interfaces. The 500+ bar system could be used in production from 2022 onwards.