Effectiveness of Fuel Pump Voltage Booster (Boost-A-Pump)

OK, real quick (I'll elaborate more later, it's Thanksgiving right now and Turkey is in the oven, LOL), but I'm pretty excited about the results so far.

I've always felt the LPFP was inadequate to make serious HP. Even with injectors and a HPFP we are forgetting to address the source of fuel. With those larger injectors and HPFP, you basically have a fire hose connected to a garden hose bib. You'll never be able to utilize them to their full potential when pushing the limits of the platform. Well, the problem really manifested when switching to e85. Brad (AJP Turbo) noticed in the data log as we were tuning that the low pressure side was dipping pretty low and the HPFP would follow with a dip. Even with a DW300c in the fuel module, it was faltering. It's just not enough to make serious power, especially on corn...

As some of you know, I've been trying for quite some time to address this issue and decided to implement old school solution to increase flow for now. Enter the boost-a-pump (usually referring to the Kenne Bell version) from JMS. There are a few versions from other manufacturers out there, but the JMS has the reputation of having the cleanest output signal.

Those of you who are trying to make serious power, it may be worth entertaining the idea of installing one. It's relatively easy and I'll be doing a write-up on it in my build thread shortly. Just wanted to share my preliminary findings.

Brad is still tuning but he's super happy about the pressure staying way more stable and here is a log to illustrate, everything is 100% equal except for the BAP. The tune is the same before and after, so it's easy to see the improvement:

Charts are isolated to a 3rd gear run from 2k RPM to 6k RPM. Showing:
- LP Pressure DSD (Brown)
- LP Actual (Green)

Without BAP, you can see how it just can't keep up with the requested pressure:


With BAP, it can still use some help at the end, but way better:


Stock, the fuel pump driver module never puts more than 14.10v to the pump (actually higher than I was anticipating). The DW300c is stable up to 18.00v, leaving almost 4.0v on the table. Right now, I am using a 0-5v trigger input from the pedal position sensor and have it ramping from 14.5v to a max of 17.0v at WOT.

Anyway, wanted to pass this on so that those who are on the cutting edge ( @bpd1151 @Jordan_R @802SHO and I may be forgetting some of you) can possibly use this as a very viable solution to get that HPFP the fuel it needs.

Anyway, I have ANOTHER LPFP solution on the way that may blow the doors open for our platform and maybe even change the game...stay tuned...

 

Appreciate the insight and advice.

Subscribed for the future developments/updates as they occur.

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Been a while since I've heard of boost a pump on this forum. That's been a work around method used for a while.

 

Beautiful! I am definitely going to go this way in the future. Looking forward to your install post

 

Yup...what's old is new again, lol.

With the more recent release of bigger injectors and higher output HPFP, this is a more viable solution toward the "total package".

 

Yup.

Last person I recall to bring it up, was EcoBrickBob (Bob Moser) which was about 7 to 8 years ago.

Never really went anywhere cuz there wasn't the ancillary supporting mods available at that time. Least not for this platform.

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Count me in! I’ve seen the craptastic LPFP dips and HPFP playing follow the leader in my own logs on just E40. It’s an issue and it looks like this is a clear solution. Equally interested in this and your secret project to address this.

 

I am watching this closely I was thinking that maybe adding a fuel pump inline a supplemental pump to get more flow will keep an eye on this for sure.

 

I did have something similar when I went with the bigger turbos. lpfp could not keep up and when I sent logs to Matt he pointed it out. He also noticed the sct tables didn't have the values put in for my strategy at the top end. He sent in a request to have sct up date them and I had Brad update his and this fixed the lpfp. I'm not a tuner by any means and am just telling you guys what I was told. Now my hpfp puts out 2900 psi, I will try to dig up the logs.

 

sssssshhhhhhhhh! here's my "other" LPFP project that is ongoing...but don't tell anyone yet ok, LOL (whisper):

Not even sure it will work yet, but here's a sneak peak:

 

Would someone like to take a stab at making me understand/believe why any of this is relevant and necessary to feeding a positive-displacement mechanical HPFP?

And you know I have to ask- are you still rocking that OEM fuel line?

 

Sigh.......

 

Two is always better than one so this clearly WILL work. Anyone who knows anything, knows that.

 

Is this from a 3.0L continental/mkz set up?

 

Nope....lol, not even close...

 

It worked for me. The stock pump in my Flex (sold in 17) was operating at up to around 10 volts and varied based on need since there is no return line like most GM vehicles. The Kenne Bell Boost-A-Pump increases voltage up to 50% and has a knob to adjust that. In the Flex, the LPFP relay is on the passenger side C-pillar, which is where I was told to wire it in. In my Flex, after the Boost-a Pump was installed, my HPFP had the lowest pressures at the highest RPM's in 2nd gear where my pressures went down to as low as 1300 PSI and my boost PSI was highest with my Lambda numbers high enough to keep from a serious lean condition. Without the pump, Torrie couldn't tune for the maximum boost. Ideally, a bigger in tank pump is the best solution however. And you might need a larger fuel line to utilize bigger turbos and other mods. I asked about adding e-85 system, but even with the stock LPFP sped up with a Boost-a-Pump there wouldn't have been enough fuel.

Mine is still in my garage along with several methanol pumps and hardware that are mostly new and never used after my over spraying issue. NEVER lug a boosted engine... NEVER!

 

Not going to lie, I was wondering about this as well.

Is the HPFP only increasing rail pressure vs pulling volume from tank in a traditional sense?

 

Correct. The HPFP's primary purpose is to increase pressure not volume. It cant move any more fuel than what's being given to it. Boost-A-Pump's have been around for decades and are a temporary bandaid that wears out LPFP's faster. Interested to see what Ecoboost_xsport comes up with in the dual pumps.

 

CTS-V?

 

LOL...we are basically concerned with 3 variables as it relates to fuel; pressure, volume and velocity. Pressure in a PWM returnless system like we have is being controlled by the FPDM and isn't going to change outside of what the PCM is asking the FPDM to do and limited to the fuel pressure relief valve set point (aka regulator) that is in the fuel module. Since the demand for e85 is especially high, the positive displacement pump that @stripSHO so eloquently pointed out is only able to increase pressure downstream from it (the injector rail) and doesn't "siphon" (at least not adequately enough) the fuel into itself...hence the entire need for a LPFP (which is, for all intents and purposes, basically acting as a transfer pump). As @RoketRdr mentioned, it can only increase pressure based on what it's being fed. Which means we need to increase the volume of the fuel OR the velocity at which the fuel is being fed to the HPFP. This is where a BAP or a larger LPFP comes into play. As for the fuel line sizing, for the time being, the increase in volume and velocity of the fuel can flow through the existing size. The HPFP is currently "empty-ing" the existing fuel line faster than it can be "filled" by the LPFP, which manifests as lowered pressure on the LP side. However, @stripSHO is correct, there will come a point where the fuel line will need to be increased in size when moving up in the HP range, I just don't know where that threshold is at...

To put things into perspective on sizing, the fuel line that is being utilized in the donor vehicle I've secured the dual pumps from and experimenting with has the same size line as our platform and is currently making much more power with a much larger engine...