boostedsl2

Figured I’d show you guys how I added an A1000-6 adjustable fuel pressure regulator using the stock rails. I also added a few pics of the Precision 650 CC High Impedance injectors. These injectors are re-packaged Siemens Deka 60 lb/hr 4 Motron High Impedance (Long Style) EV1.

The rails are spaced using 0.500” Aluminum tube. Cut them down to the right height with a band saw. Used 6mm x 1mm threaded rod, washer and 6mm x 1mm spikes to hold them down.

The bypass does not have to have an NPT port cut in it. I added one because I had to plumb for a fuel pressure gauge.

Here’s a part list:

1-Aeromotive A1000-6 Regulator
1-Custom Stock FPR bypass – Cut from 6061 T6 Aluminum stock
1-Russell 640863 -6 AN Male to 5/16" SAE Quick-Disconnect Female Push-On EFI Fitting
1-Russell 640930 -6 AN Male to 5/16" SAE Quick-Disconnect Male Push-On EFI Fitting
2-Russell 610023 ProClassic -6 Straight Full Flow Non-Swivel Hose End
1-Russell 613403 ProClassic -6 AN 120° Full Flow Swivel Tight Radius Hose End
1-Russell 613163 ProClassic -6 AN 90° Full Flow Swivel Hose End
2-Russell 670840 AN O-Ring Boss Radius AN Port Adapters -6 AN to Male -6 AN O-Ring
1-Fragola Performance Systems Plug 481406-BL O-Ring Plug -6 AN
1-2' -6 AN SS Hose

Ferocity02

iTrader: (59)

Nice! You could probably just gut the stock FPR so you don't need the custom piece to plug the hole.

boostedsl2

Not as easy as you would think. That was what I intended on doing, but once I took it apart it wasn't very straight forward. Stock one has a bunch of crap stacked up. there's a plastic filter, plastic spacer and the o-ring that hold it in place. I guess you'd have to see it.

I believe you can turn out the stock star screw and replace to make it adjustable. The one thing about doing that is the port that allows fuel to bypass is less than 1/8". When you take out the stock filter/bypass port it opens up the hole quite a bit. I intend on installing at least two 340L's, so I'll need to bypass a bit at idle.

The piece that I made is not a plug. it's a bypass (hence drilling out the center of the plug a bit). You still need fuel to enter where the stock pressure FPR installs and exit through the stock return line.

I'll try to post up some pics later. I'll also measure the stands for the rails.

you can see where the fuel comes into the stock FPR and returns out to the tank in this pic

GMCtrk

iTrader: (27)

I really like what you did with this.

Do you have any more of the block off plates for sale?

Also, I want to get your thoughts on how effective this is versus going to aftermarket rails. Right now my fuel system is completely STOCK minus 2 walbro 450s in tank. I'm having serious fuel delivery problems right now. I want to get that fixed so I can up the boost more.

So, just to confirm, on the stock system, the fuel has to go through the stock FPR before it reaches the rail, correct? If so, that potentially explains why I can't get more fuel to the rail (versus the stock fuel feed line size?). If the fuel first has to go through that small hole, can that whole portion just be drilled out to make it 1 big hole?

I know ideally, I should just do aftermarket, rails, lines, regulator and filter but I want to keep things as easy and cheap as possible.

boostedsl2

The stock fpr is removed. The bypass fitting allows fuel to pass by where the stock fpr was.

You can't drill out the stock return port because it has a few bends and is part of the rail.

I'm not sure if it'll work with two 450s. The stock fpr port is maybe 0.100" at most. If you remove the bypass, the line after is double that. I can get exact measurements tomorrow.

The other question is why you're running stock lines and rails for 1800 hp worth of fuel lol. Twin 255's will support 1000 whp. The bypass deal should handle a single 450 and I would imagine twin 255s or 370s. I am going to throw a second 370 in when I run out of fuel, but thst could be a while.

The stock rails are actually bigger than billet rails, so from a comparison of just the rails it won't help. The lines are a different story. You will benefit from running bigger lines and have better control. Keep in mind that if you're using the stock tank and hat, you'll never get the benefit out of the bigger lines, with the exception that a bigger pressure side will allow more fuel to discharge if there was ever a total pump failure. Stock feed is 3/8 and return is 5/16. Works out to a 6 an feed and a 5 an return. Therefore they will neck down to those sizes at the hat regardless of you line sizes after.

The question is do you maybe have too much pump for your goal?

GMCtrk

iTrader: (27)

I'm not sure you totally understood what I was asking. To me, it looks like under stock circumstances fuel coming into the rail from the feed line has to first go through the stock FPR and then is distributed to the rails. Therefore, the stock FPR would be a restriction on the feed.

I am running E50/E85 and making 800 rwhp so, no 2 450s is not overkill. 1 450 is only good to around 600 rwhp.

Also, how true is your statement that I won't benefit from bigger lines with a stock hat? Resistance is a function of length as well, and the stock hat is hardly any length compared to the length of the fuel lines. Note that the output on the walbro 450 pump is only 5/16" in diameter.

Yes, I know I should do a full aftermarket fuel system. However, I want just that little extra bit of fuel delivery so I can push this heavy beast in the 10s.

GMCtrk

iTrader: (27)

Also, only 1 450 is on during idle and driving. 2nd 450 comes on at 3 psi.

boostedsl2

You'll need 185 (900l/hr = 237 gallon/hr = (237*6.3(weight of gallon of gas) = 1493 lbs/hr / 8 = 185 lb/hr per injector) lb/hr injectors to get the full potential of your two 450's and you're shooting for almost 1500 hp ~ 1200 whp (185*.70(E85 requires 30% more fuel) = 130 lb/hr. 1475 bhp, with BSFC of .6 and 99% duty cycle with a base pressure of 43.5 psi = 112.39 lbs/hr) , which is what 185 lb/hr injectors supports at 99% duty on E85.

I'm not sure if the stock ecu will idle 185's very well. I know some guys run id 2000's and have success, but I imagine their idle is around 10~12:1 AFR.

This thread is for return type fuel systems. If you have a return type fuel system, you will have a 3/8" pressure feed line (from pump/fuel hat) to the driver side rail. from there it fills the passenger side through a 3/8's line and also fills the driver side from the rail entry.

The driver side acts as a manifold with the FPR built right into it which exits through the 5/16 line and eventually dumps back into your fuel cup in the tank to be re-used. My bypass removes the stock FPR so there is no restriction, which is why you plumb an external FPR into the 5/16 return line.

two 450's outputs is equivalent to .44 line which is closer to 1/2" (-8an) than 3/8" line (.375). Usually you can overcome line size by upping the pressure, but I wouldn't suggest it. You'll start popping out injector o-rings.

If you have a returnless type system your FRP is built into the fuel cup which is before the hat. It vents pressure before it exits the tank. In that case you will have a single 3/8 line running to one of the rails with a cross hose to feed the other. If that is the case, this little fix is not for you.


*** Short answer: I have no idea if this will work for you. You are welcome to use the diagram to get a bypass cut or if you'd like one, my buddy is having a run made. You can PM me for his details. He's not a vendor. You might be in better shape because you're running E85 because of the 30% more fuel required, which means you potentially holding back less fuel. This will allow you to drop base pressure because there is less fuel exiting the rails.

I could be wrong about all this. Anyone else have any input?

Atomic

iTrader: (42)

Good stuff here, but I think your BSFC is a little optimistic for the first part. I usually figure around 0.7 for these trucks on gas with a turbo, and use 1.0 for e85 with a turbo. I based that off of what mine made on a dyno.

You need to consider at what pressure you are operating as pump flow decreases with pressure. The walbro450 flows 455l/hr at 30psi, but at 60psi it only flows 380l/hr and at 20psi of boost with a normal 4bar base pressure, it only flows 330l/hr.

Pressure drop through the hose also matters. AN hoses are sized a little differently than tube sizes and are slightly larger. A 3/8" tube is smaller ID than a 6AN hose.

Luckily I did all this stuff (pump flow, injector flow, pressure loss, power estimates, unit convesions, etc.) and put it in a spreadsheet if you want to take a look. https://www.performancetrucks.net/fo...p-flow-510434/

5.3 GMC

Stupid question, but what do you have screwed into your bypass? Could you not just machine a plug for the factory fpr and put it in. I may have missed something when I was reading. I'm looking to upgrade from the stock one and like what you have done. Thanks for the info.