05yellowgt
New member
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#msg2519
Now, 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.html
Here are the numbers from that thread.
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.htm
IF (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!
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#msg2519
Now, 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.html
Here are the numbers from that thread.
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.htm
IF (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!
