I'm trying to find as much information about the 3.5 Ecoboost DI fuel system as possible. I'd like to get it all in one thread for convenience purposes.
The Fuel system that powers the 3.5 Ecoboost is made up of two sub-systems. Those systems are the low pressure feed system and the high pressure Direct Injection system. The low pressure system consists of a returnless setup, consisting of an in tank pump that delivers fuel to the High Pressure Fuel Pump (HPFP). The HPFP is a mechanical pump with an electronically controlled pressure relief system that manages the fuel pressure delivered to the Direct Injectors. The pressure can be regulated up to 2150PSI.
4DRHTRD has created a solution to the limits to the HPFP issue by creating an Auxiliary Fuel system by modifying a stock intake manifold to accept port fuel injectors and used a stand alone fuel controller to handle the port injectors. A good link to read up on it can be found here.
http://www.ecoboostperformanceforum.com/index.php?topic=462.msg2519#msg2519Now, let us try to dig into the HPFP itself. It is sourced from Bosch and is mechanical in nature. It is driven by an extra cam lobe on one of the cams on the driver's side head (on the F150). This cam lobe is 4 sided, meaning that each revolution of the crankshaft, actuates the HPFP 4 times. The system has an electronically controlled bypass to regulate the fuel pressure up to a maximum of 2150psi. I've been digging to find specs on the fuel pump itself and haven't found any definitive information. The following thread quotes some flow numbers that I will show below.
http://www.svtperformance.com/forums/f-150-274/914450-2013-ecoboost-f150-dyno-today.htmlHere are the numbers from that thread.
QuoteBased on the data from Ford the HPFP is capable of flowing a maximum of the following fuel volume in lb/hr vs RPM:
RPM - LB/HR
500 - 30.1606
1000 - 60.3211
1500 - 90.4817
2000 - 120.6423
2500 - 150.8028
3000 - 180.9634
3500 - 211.1239
4000 - 241.2845
4500 - 271.4451
5000 - 301.6056
5500 - 331.7662
6000 - 361.9268
It is RPM based since the HPFP flows x volume per cam revolution.
Given the flow rate you can calculate the Max BHP attainable (without draining the fuel rails) vs RPM.
Converting those numbers from LB/hr to L/hr of gasoline you come up with a maximum flow potential of about 227L/hr of gasoline. 227L/hr can support somewhere somewhere in the 500-550Bhp depending on the BSFC of the 3.5 Ecoboost. (something I would love to know as I have looked for hours and can't find the BSFC for a stock 3.5 Ecoboost motor). That would jive right about what we are seeing as far as data logs on most tuned Ecoboost 3.5's. Even Boost only tunes can show the fuel pressure starting to fall off, though not to the point of leaning out the motor.
Doing some math, I can work backwards and figure out that the stock pump flows .15 cubic centimeters of fuel per stroke. I have found a Bosch website that lists a series of HPFP's that all flow 1.1 cubic centimeters of fuel per stroke. site can be found here.
http://www.bosch-motorsport.de/content/language2/html/2832.htmIF (and I'm making some assumptions based on my crude math of the flow of the stock pump) my math is right, the Bosch Motorsports pumps should provide around 2500lb/Hr of fuel at the same 6000rpm. In my mind that should provide all the fuel we'd ever need, provided it can keep up the volume and pressure.
Finally getting to the Direct injectors themselves, I have found no flow data for them. Hopefully we can add that later as we learn more.
Edit: added additional low pressure fuel pump info. Thanks to EcoBrick Bob!