[shiv@vishnu]

Hi guys,
I hope everyone is enjoying their Christmas and is looking forward to the 2013!

There also seems to be a little confusion with regards to fuel system design. Specifically, the Low Pressure Fuel Pump (LPFP) system and how to upgrade it. I don't have too much time so I'll make this quick. There are 3 ways to upgrade the fuel pump for those who want to support higher HP levels or run high concentrations of ethanol. We've tested all 3 over the past 2 years. Here's what works well and what doesn't (as others have, and will soon, find out).

1) Running the factory fuel pump at a higher voltage. By running the stock fuel pump at 15-16v, you'll see 10-15% more flow. So a healthy pump that flows 350lbs/hr at 14v will now flow somewhere around 390lbs/hr. Similarly, a less-fresh factory pump that flows 300lbs/hr will flow around 335lbs/hr. Not a huge gain and probably not a good tradeoff given the added stress to the pump (which means lower lifespan).

2) Replacing the factory LPFP with a Walbro E85 pump. This approach is better than the first. A Walbro flows 420 liters per hour (LPH) at 43psi. But like most fuel pumps, flow falls off rather abruptly as pressure goes up. At the N54's 72psi of pressure, the Walbro flows approx 350LHP. Which translates to approx 570lbs/hr which sounds great until you realize that got rid of the stock pump and that this pump doesn't offer a dedicated secondary vent, you have to put in a T in the outlet to power the Venturi jet (in order to keep fuel bucket nice and full at all times). This will drop effective flow (flowing going upstream to the regulator) by 15% (or more if the line isn't sufficiently restricted). Which means that the system flow can easily drop to 485lbs/hr. So compared to a fresh stock pump which flows 350lbs/hr, you're picking up approx 38% more flow.

3) Running a modified Walbro in series with the factory pump. This is essentially what we are doing with our Vishnu/FFTEC in-line fuel pump upgrade. The disadvantage of this approach is obviously cost since you have to machine an adapter that converts what is designed to be an in-tank pump into an in-line pump. This also requires additional lines and fittings. The upside is that you don't have to modify the factory LPFP assembly (cutting it open). The other upside is that running two pump is series drastically outperforms (and outlives) either of the previous two options. Here's why...
When you put two pumps in series, the total system flows approx 20% than the higher flowing of the two pumps assuming no inlet restriction (more on that later). Which means that the Walbro, which flows 570lbs/hr will now flow approx 685lbs/hr assuming the pump upstream keeps doing its job. This is because it will operate a lower pressure ratio than it would if it had to work by itself. This is because it is getting pressurized at the inlet (to ~35psi) which means that it is only stepping up pressure by another 37psi instead of having to work from 0psi as it would have if it were working as a lonely in-tank pump.
The factory pump is also working less hard since it is operating at approx half the system pressure it would otherwise operate at. And with the drop in outlet pressure, the factory pump sees a big increase in flow (up to 480lbs/hr from the 350lbs/hr it provides at its usual 72psi). This is well matched to support the needs of the Walbro upstream up to ~800hp on gasoline or ~620hp on straight E85. Above that, it will start to run out of steam and start to drop outlet pressure, forcing the Walbro to operate a higher pressure ratio which will limit fuel flow to the output we saw in the first part of approach #2 (before a portion of the outlet was bled for the venturi jet). All said and done, running both pumps in series improves flow to approx. 570lb/hr, or a improvement of 62% over stock.

And yes, we've make some big numbers on this set-up And it is alway a good idea to "oversize" your fuel system because pumps do constantly degrade over time.

I've also attached a pic below of the prototype fuel system running in our shop car. It's an evolution of (add-on to) our in-line fuel pump upgrade. Designed for 800+whp on E85. With it, the car has 3 pumps, 3 regulators, a surge tank and Teflon coated SS line conversion! You don't want to know the parts/labor cost on that

Hope that sheds some light on things....
Happy Holidays!
shiv

[The Ghost]

When will the booster pump be available? What is currently preventing you from going to production, as you posted it months ago?

Thanks

[shiv@vishnu]

Originally Posted by The Ghost

When will the booster pump be available? What is currently preventing you from going to production, as you posted it months ago?

Thanks

It is already in production. Many forum members already run it. It can be purchases through either us or FFTEC. Our website will be updated accordingly by the New Year.

[The Ghost]

Originally Posted by shiv@vishnu

It is already in production. Many forum members already run it. It can be purchases through either us or FFTEC. Our website will be updated accordingly by the New Year.

Rock the house! Thanks Shiv

[Ænema]

Why not just run a single LARGE in tank pump? Running 3 pumps and mulpile pressure regulaters seems overly complicated to me.

[shiv@vishnu]

Originally Posted by Ænema

Why not just run a single LARGE in tank pump? Running 3 pumps and mulpile pressure regulaters seems overly complicated to me.

You'd be surprised at to how few aftermarket pumps are designed to support high flow AND high pressure for sustained use. And those that are, are way too loud to use in a street car. Therein lies the need to use multiple pumps in series. The primary pump we use in my own car is a 1200HP Prodigy digital fuel pump FuelLab. By their own admission, during a talk we had with them at SEMA, it would not have lasted long in an application that runs 72psi static.

Shiv

[shiv@vishnu]

Here's some sort of rebuttal from Terry@BMS

Did you know that 78% of statistics are just made up on the fly?

As far as I know the Walbro "267" pump is rated @ 355 liters/hr @ 70psi @ 13.5v on paper. 1 liter/hour is 1.63 pounds/hr for gasoline. More for E85 of course. So with no over head it's rated at 578 pounds/hr worth of gasoline.

Ok

Depending on how you configure the system there is overhead with the two venturi jets, the regulator, lines, etc, which I have not measured.

Why have you not measured this? Aren't you suggesting this upgrade to others?

But that overhead is present with any setup. Since I don't know the exact overhead I can't give an exact theoretical effective rating on the pump. But I can say with RB turbos using E98 it held full low pressure target in the 520whp+ range running 11.8:1 air/fuel ratios. With a leaner E85 specific air/fuel ratio, lower BSFC from a more efficient turbo setup, etc, I could see it supporting 700whp+ without a hitch. People have made a lot more than that using this single pump. And one could restrict both venturi valves more than they already are for more flow if needed

.

You are bleeding off the 70psi pressurized output of the pump to feed the venturi bleed (a plastic fitting no less) and yet you haven't measured the effective flow reduction? Maybe you should do that before trying to convince people that your solution is sound and that ours is less so. For someone who didn't even understand how a venturi jet worked or why removing it was a no-no until I told you, you should take a back seat here and just sit back and learn. You have no business recommending unquantified solutions to others, let alone attack us for providing a solution that works.

PS. It's interesting your "2 year in the making" fuel system upgrades just happen to also use the first pump I came across on eBay and ordered with maybe 20 minutes of research...

2 years in the making? Hardly. But it is pretty clear which one of us spent the last 2 years of our time developing fuel system upgrades more effectively. When we get back to the shop after the holidays, I'll post a video and flow test results of both option 2 and option 3. I encourage you to do the same.

And my apologies to the forum members here for the semi heated response. As hard as we try to stay in holiday spirits, it gets annoying when competitors spend more time spreading and encouraging misinformation and ill-will towards others than than they spent actually testing and developing new product. It gets old. While some do like the drama, it really detracts from the development of this platform. We stepped away from the on-line drama last year we ended up with a single turbo and fuel system solution. And we hope to cross another milestone within the next few weeks. I encourage Terry (Sticky and a few others) to do the same.

Shiv

PS. Attached are some test results of the stand alone Walbro E85 pump being discussed (obviously, without an output bleed for an add-on venturi jet).

[shiv@vishnu]

Another replay by "Flinchy":

LOL

i almost believed some of that post until i read '3 pumps for 800+ on e85'


aaaahhhhhhaaaaaaaaaaaah

there are local 1500hp+ gtr's and supras running two pumps

No kidding. But they do not have a HPFP as the last stage of the fuel system. So you are comparing two different animals.

if it's going to 'need' an eleventy billion dollar shiv magictouch(tm) fuel upgrade to support high power levels... I'll wait for proefi to bring their PI manifold/tuning to the table.. And be happy with what terry/the rest of the community can provide in the meantime, at least there's no bsing there..

The only BSing here is what you are doing to yourself. You don't understand the basics yet pick a "side" based upon emotions. Unfortunately, emotions don't make give your car a lot of power. But they are easier to get comfort from when you are on the losing side of a technical debate.

i'm sure shiv's upgrade is an upgrade, but if he's not going to give hard evidence for the price, may as well just poop on some graph paper...

Hard evidence? How does 650whp on E85 alone sound? Or 700+whp on E85+meth sound? Or flow bench data I gathered and published a year ago after a visit to RC Engineering? At the end of the day, my job isn't to provide haters with hard evidence. The only hard evidence I need to provide is a functional product that works as advertised. It seems as if there is a group of people (yourself included) that are more interested in being a part of a hate mongering 'boys club' than actually learning about makes our car tick. If that is what floats your boat, go for it. Just don't pretend that you are here to learn and are open to ideas. You embarrass yourself and alienate yourself from those who are actually want to learn and try new things.

[shiv@vishnu]

From Dzenno:

Thanks for the data and looking forward to seeing more. I do like what's been presented. The only thing I don't like the sound of is the fact we'll be running 4 fuel pumps now (3 LPFP and 1HPFP) instead of 2 OEM. Troubleshooting issues is already a bit of a nightmare with the 2 OEM pumps. However, it does also "seem" like having these pumps in series will make the numbers required and take off some of the load off the OEM LPFP making the overall low pressure system work more efficiently while providing more flow. I guess time will tell if this is marketing at work although at this point I doubt it as no one in their right mind would have 3 pumps there unless absolutely required (unless you're trying to make it look more complicated than it is to turn a profit ).

You were doing good right until the last couple sentences when your true intentions got the best of you. If you have a better solution, have at it. Because there is no no glory at sitting by the sidelines and taking pot shots at others who are offering solutions that everyone will, either directly or indirectly, benefit from.

Overall, I'm glad there seem to be options for more fuel before hitting HPFP and Fuel injector limitations. Looking forward to more updates and discussion.

Just to clarify, the prototype fuel system in my personal car (3 LPFP pumps, 1 HPFP) is just a engineering exercise to test the viability (and limits) of a certain fueling approach. It is not something that is destined for production in it's current state. Not only would it cost a lot, it also involves some pretty extensive modification of the factory hardware (FPR, fuel filter assembly, level arm, fuel lines, etc,) that isn't in-line with what most people are willing to do at home with basic tools.

Shiv

[tcw]

Originally Posted by shiv@vishnu

And we hope to cross another milestone within the next few weeks.

Hmm... what might this be?

[nkadisha]

Great info from Shiv

[shiv@vishnu]

Hi guys-- Made a mistake on the first post which has been corrected. Accidentally used the flow numbers from a different Walbro pump. Too much eggnog With the correct flow numbers used, the relative flow differences between the 3 approaches are even greater. The basic gist of things is that keeping the factory pump in there (and not replacing it) and running the Walbro E85 pump in-line means that:

1) You are not sacrificing pump output to feed the venturi jet. Which means more fuel flow to the engine.
2) You are keeping both pumps running at a lower pressure ratio which is especially important for the Walbro pump which is not designed to run a differential pressure of a continuous 72psi. This means longer lasting pumps.

Shiv

[Zebra99]

From all your info. I take that these vehicles don't consistently run the high pressure (72psi) on their fuel systems as we do. And that to me means more stress, more pressure and consistent running this means more wear. This the need for two pumps for support.....

Here is a stupid question....

Would it not be viable and easier to run a single pump system like the GTR's, Supra's and the like?

I know nothing about our fuel system other than the basics, but it just sounds like BMW made it extra complicated for no reason lol...has to be something to it tho.

[shiv@vishnu]

Originally Posted by Zebra99

From all your info. I take that these vehicles don't consistently run the high pressure (72psi) on their fuel systems as we do. And that to me means more stress, more pressure and consistent running this means more wear. This the need for two pumps for support.....

Here is a stupid question....

Would it not be viable and easier to run a single pump system like the GTR's, Supra's and the like?

I know nothing about our fuel system other than the basics, but it just sounds like BMW made it extra complicated for no reason lol...has to be something to it tho.

Both the cars you mention run lower static pressures and do not have a crank driven HPFP at the last stage of the fuel system. So they aren't constrained by relatively high pressure requirements and pressure limitations in the fuel rail. Then again, they also don't enjoy the benefits of direct injection (knock resistance, off boost torque, lower emissions, etc). With the n54, being able to support up to 800whp (on gasoline) is pretty straightforward. Much above that and things will get trickier. Keep in mind that this is 300% over stock! With nothing more than an in-tank fuel pump add on. Most other vehicles would require injectors, fuel rails and a fuel pump to support that relative power gain. We really should be happy with what BMW gave us to work with.

Shiv

[drfrink24]

What are the limitations of the HPFP?

[Zebra99]

A need and a cause....I figured.

I'm actually very surprised tho that an aftermarket carrier hasn't yet done any R&D to actual solve this problem....Walbro has made a "fix" just as you guys have done as well, which is great for now.

I'd love to see a permanent upgrade which is 1 pump running as simple as possible to obviously avoid crazy complex set-up'd and high costs

But great work thus far.

Maybe in two years when I pick up an E93/F33 again this will be resolved and any 600whp+ vehicle is using this "new" pump I speak of lol

[Aridk]

Merry Christmas to you all

Just a couple of questions:
1. How noisy is this in-line pump in the trunk? Will it be annoying in a daily driven car?
2. with all this extra flow of fuel running through the oem fuel lines will it be beneficial to run a fuelcooler at some time?
3. When wil we see a RB 100% E85 with this upgrade?

Keep up the good work Shiv, don´t let all the negative folks get to you

[dfjaws]

Originally Posted by Aridk

Merry Christmas to you all

Just a couple of questions:
1. How noisy is this in-line pump in the trunk? Will it be annoying in a daily driven car?
2. with all this extra flow of fuel running through the oem fuel lines will it be beneficial to run a fuelcooler at some time?
3. When wil we see a RB 100% E85 with this upgrade?

Keep up the good work Shiv, don´t let all the negative folks get to you

Interested in this as well.

In addition, is this something that ultimately needs to be controlled by the Procede or is this something that any car could benefit from?

Thanks!

[scottp999]

Great info Shiv. Please come out with a flash at home option soon for those who don't want to mail out their DME.

[BlackJetE90]

Originally Posted by shiv@vishnu

Hi guys-- Made a mistake on the first post which has been corrected. Accidentally used the flow numbers from a different Walbro pump. Too much eggnog

Scanning BB helped you catch your error. A little ironic.

[shiv@vishnu]

Originally Posted by drfrink24

What are the limitations of the HPFP?

There is a physical flow limit to the HPFP. Which means that there comes a point that the injectors can demand more fuel than the HPFP can deliver which will result in a reduction in fuel rail pressure. But this is at a pretty high power level. The bigger constraint is the 72psi input pressure it requires at all times. That's a pretty tough job for most streetable fuel pumps.

Originally Posted by Aridk

Merry Christmas to you all

Just a couple of questions:
1. How noisy is this in-line pump in the trunk? Will it be annoying in a daily driven car?
2. with all this extra flow of fuel running through the oem fuel lines will it be beneficial to run a fuelcooler at some time?
3. When wil we see a RB 100% E85 with this upgrade?

Keep up the good work Shiv, don´t let all the negative folks get to you

1) It's not noisy at all once the seat cushions go back on. If you listen carefully with the car stationary and with the radio off, you may hear a very subtle hum but you'd be hard pressed. The only time when its obvious is when the fuel pump primes as you unlock the doors first thing in the AM.

2) Continuous fuel flow is only increased in the 2-3" long section of fuel between the two sides of the fuel tank (between the pump output and the FPR). The long line that runs under the car (to the HPFP) only sees fuel flow in proportion to power output. Fuel coolers can always help (especially when running E85) but i don't think they are necessary at this point.

3) As soon as I get my hands on one. Either that or a Vargas Stg2 which should be hitting the streets soon around here.

Shiv

[shiv@vishnu]

Originally Posted by dfjaws

Interested in this as well.

In addition, is this something that ultimately needs to be controlled by the Procede or is this something that any car could benefit from?

Thanks!

Nope. It's a stand-alone product. Had nothing to do with the kind of tune you have.