State your HPFP Woes/issues here
 

I am starting this thread because we are tuning stock turbos this week in order to release a few power packages. Lord willing, we are installing the VTX-56 turbos this weekend. Most of the upgraded turbo conversation side tracks to fueling arguments, so I am heading this off and opening up the HPFP conversation now. There is an amazing article which can be found here: http://www.underhoodservice.com/issu...ontentid=68338
which outlines the fuel system of the SHO. The SHO and EBF150 have many commonalities as well as differences In fact I think that the 2013 F150 ECU is pulled from the SHO (I could be wrong, but I remember reading that somewhere) The fueling systems are extremely close in operation. That article is worth a read or even two. I pulled some highlights to get a better understanding of what is happening when your truck fuels itself.

http://i58.photobucket.com/albums/g2...ps957aebc2.jpg

http://i58.photobucket.com/albums/g2...ps2b25b8e2.jpg


Low side:
"There is no low-side pressure sensor, yet the PCM does control the low-side pump speed via the control module. The low side has two speeds: low and high. To achieve a low speed, the PCM sends a 37% duty cycle signal to the fuel pump driver module (FPDM), which in turn, operates the pump at around 60% capacity. If the PCM determines a need for higher fuel delivery, it can increase its (HPFP) duty cycle to 47%, which will raise the low-side pump’s operating capacity to 100%"

HPFP

The high-pressure system consists of a high-pressure fuel pump that is mechanical and driven by a special four-point camshaft lobe that is only for pump operation. The plunger action of the high-pressure pump boosts fuel pressure up to 2,150 psi. The high-pressure fuel is in the metal line leaving the pump to the rails as well as the fuel rails. There is also no return line in the high-pressure system. The high-pressure pump mounts on the left valve cover. Pressure in the high-pressure system swings widely with rpm and demand. Pressures here will swing from as low as 1,000 psi to 2,150 psi depending on conditions. Pressure is controlled by balancing the volume through the pump and into the rail versus the volume passing through the injectors. One complete revolution of the camshaft produces four strokes of the high-pressure pump. At maximum, these four strokes equal 1 cc of fuel delivered to the rail. If met with a dead end, that 1 cc of fuel would raise the rail pressure by about 800 psi. The injector cycling will vent that fuel into the cylinders at around 21 cc per second. The PCM raises and lowers the high-side fuel pressure by pulsing the fuel inlet valve (solenoid) on the side of the pump. The inlet valve controls not only the amount of fuel that enters the pump chamber, but also the amount that bleeds back into the low-pressure system when the pump’s plunger pushes the fuel out. The more the pump is filled, and the less that bleeds back into the low side, the higher the pressure will be in the rails. The PCM monitors a fuel rail pressure sensor to determine the needed action at the volume regulator. The pressure sensor is mounted to the top of the left-hand rail.

The low side upgrade is a simple off the shelf Walbro 255. The HPFP is a lot more complicated. I have had a multiple conversations with engineers, and companies that have upgraded HPFP's in the past and they all agree that we should test the limitations of the stock HPFP with our VTX-56 turbos and act from there, so we will see.

My tuner was supposed to give me a few screen shots of the data logs showing our HPFP duty cycle, but he has been road tuning the truck all night, so it will have to wait. I have been searching for information on the fueling system here and other forums and have seen some feedback such as the pump not being able to push more than 2,150 psi. I cannot speak to what I do not know. We have had no fueling issues at 17psi, but it is not to say that we wont when we install the upgraded turbos. Feel free to post your issues and here, I hope this information helps, lets talk!

morkindesign.com

Threads like this are the reason I joined the forum. I love technical discussions and learning new technology.

i wish i had a local here with a vw fsi pump upgrade that autotech sells, would be interesting to see if the guts would swap in.

the vw/audi pumps are mfg'd by hitachi, max pressure of 1650psi. you can swap aftermarket guts to boost up to 2150 psi

the ford f150 ecoboost pumps are mfg'd by bosch, max pressure of 2150 psi. Ultra reliable and very high peformance for their size, i doubt you will find too many complaints or woes with it. The bosch canisters are laser welded, so you can not access any of the internals without using Wire EDM process

here is a photo of the pump internals cutaway:

http://www.full-race.com/img/article...side/HPFP3.jpg

also - yes the 2013+ PCM is similar to the SHO/Flex/explorer 3.5L due to the e-bov and the load/boost calculations

I don't know if it would work, but looking at the Bosch HPFP on the F150, it would probably have to be frozen to take apart and upgraded. It is pressed together.

Hey Geoff! Thanks for chiming in. It's great to share knowledge to help the community.

so do you guys think a better flowing low pressure would help the HPFP?

I know that is what they did over on the VW/AUDI stuff, upgraded the low pressure to keep up with the hp so it always had a high volume of fuel under positive pressure.

I think I covered that in my original post, if I understand you correctly than the answer is yes. Upgraded the low preasure pump to prevent cavitation (a void of fuel in the supply line to the HPFP). There are of the shelf solutions for that.

yea that is what i was referencing... im freakin stoked about vendors/manufacturers/rogue people that just go off and do things to make vehicles faster... normally i like to do this as well but the ol lady is like look let other people experiment keep the truck running stop taking your vehicles on and off the road for weeks at a time....

sadly she is kinda right. so in for more fuel :) bc more fuel means more air and we all know where that is going!

I need to make an edit... we technically do not know if the low side fuel pump is an off the shelf unit, but we are sourcing one out to flow test it, and get it's outside dimensions and find a bolt on answer.