ACP

iTrader: (1)

Here is some pictures of work in progress that I and doing on the fuel system.
Changing it from returnless to return.
Removed the fuel rail, cut of the ends, welded on some 6 AN fitting, and put together the Aeroquip hoses and fittings routing them to the Aeromotive A1000-6 Regulator.
From the regulator, I will ruin a return line to the gas tank.

Waiting on the fuel rail adaptors and fpr plug, so will be at a stand still for a week or so.

Here is some pictures

Sharif@Forged

iTrader: (92)

Beautiful! Very nice work.

When you are all done, you might have to play with the base fuel pressure....I imagine there is a much greater volume of fuel running through the rails, now that you've opened up the flow. So instead of a goal of 50psi at idle...you may find yourself having to drop it slightly to get a good clean burn at idle and cruise.

Very nice!!

teh215

iTrader: (8)

So the AN fittings in the front connect the 2 fuel rails but, what did you do at the rear of the motor?

ranger5oh

What exactly does this do for you?

ACP

iTrader: (1)

thanks gg

The stock configuration is only one fuel line feed to the passengerside fuel rail.
The fuel rails are connected in the back, and that is how the driveside gets fuel.

What I am doing, so putting in 2 feeds, one on the driveside, and one on the passengerside fuel rails (remove the stock dampers).
Then I have those 2 feeds coming out of the front of the fuel rails (shown above)
This will go into the fuel pressure regulator, and then one return back to the tank.

This gives me rock solid fuel pressure, and control over the amount.
This is needed for me to raise boost higher.

Soon as the fuel rail adaptors I am having made up are complete, I can finish this fuel upgrade, and go in to get dyno tuned.

Those that are interested.
The fuel rail adaptors I am having made up are a direct bolt on to the stock fuel rails.
This can be used for what I am doing above (you'll need 2) or which will probably be more common, just get one, and do way with the stock damper, and connect your fittings directly to the adaptors (AN -6)

phunk

iTrader: (21)

very good work. almost identical to what we are about to do... not as if there are many other ways to do it... but none the less, i think its really cool you did that! very nice work.

350Now

Looks Good, This should definitely give you solid fuel flow.

Sharif@Forged

iTrader: (92)

Oh, one more thing ACP. Since now, your fuel pressure will be stable at idle, and then rising as boost increases, you'll actually need to totally remap your add injector table on the eManage. The eManage base map is programmed to expect a constant drop in fuel pressure as RPM rises.....ala stock crummy fuel system. Now that you are stable, and rising (the way it should be)...you'll probably have to lean the table way out...or else you'll run super rich up top..even if you raise boost.

Good luck! I think all of us are planning on doing this in the next few weeks. Hurry up and get me my stock FPR plug....hehe...

S12 driver

Why do you need a return style fuel system? If the fuel pressure drops, can't you just use a Vortech or Aeromotive style fmu with larger injectors, but set the raising rate to 1:2, or 1:4, that would increase the fuel pressure slightly to offset the pressure drop.

derek_i

The pressure drop is happening in the tank so that is where the problem needs to be addressed. A rising rate FPR will not produce more pressure than it is receiving.

There are a few different ways to overcome the problem with the stock fuel system. The method ACP and I have chosen may be slightly overkill for 6psi boost, but it will allow us to start raising the boost and focus on programming, without having to worry about fuel delivery. Current speculation is that the engine can handle ~450rwhp, which I wouldn't want to do on a returnless system.

Also, I do not like the idea of only feeding one rail in a high HP application. I am keeping the stock connection between the rails to balance any pressure differences, but both rails are feed directly.

-D

Sharif@Forged

iTrader: (92)

The issue is primarily the intank FPR that is dumping fuel above 50psi at idle. When you are on the boost, the stock fuel pump cant supply enough fuel to keep the pressure at 50psi, so it drops to about 40psi as you hit redline.

I raising rate, as mentioned, wont work alone, since the pressure is being venting at the tank.

The only other option is to to an inline AUX fuel pump to increase pressure AFTER the tank. But this is more of a work-around solution. And what ACP and Derek are doing is text-book fuel managment...and will allow them to boost much more, and with the relative safety and reliability in terms of fuel.

I am going to do half of their solution, just becuase I dont wanna touch my fuel rail...for personal reasons.

But I'm going to plug the stock intank FPR, and install the rising rate FPR somewhere before the fuel rail and dampners, and then a return line back to the tank. I already have the Walbro 255.

Hope that answered your question.

mprowe350

GQ,
I have a second setup now and have been able to maintain pressure to redline without plugging the stock FPR. My first issue was the type of fuel tubing used. I had to switch to brass piping and fittings. The next was that I had to set the idle fuel pressure to 51lbs without the vaccum line attached. Then once the vac line is attached the idle pressure drops to 44lbs. After talking with some people this was found to be normal. So now once I hit the gas pedal the pressure rises to 51lbs and then rises from there with boost. Now the issue is that any boost over 6lbs starts to drop fuel pressure back to 51lbs and stays there to redline. Plugging the stock FPR should solve this. We need something to plug the FPR sleeve.

MIKE

EDIT: I currently have the FPR installed before the rail.

S12 driver

I think I understand what you're saying. But those people who use stock injectors, fmu and an aux pump can pump out 100+ psi of pressure, so I thought if you have larger injectors 50-60 psi should be no problem for the fmu and aux pump.

whosdady

iTrader: (6)

This is what I plan on doing if the Walbro 255 pump alone doesn't work. I have a feeling it wont.

I will be running the 9lb pulley which equates to 10psi but I am sure this idea will be sufficient for my needs.

whosdady

iTrader: (6)

GQ626,
After about 20 minutes thinking about this I decided it may be a safer idea just to install the FPR and Walbro pump, regardless if the pump works fine alone. I would hate to run lean or too rich at idle because I didn't install a $130 regulator. Do you have any more specific thoughts on how you intend to install the FPR? Are you using SS lines or plastic? Are you using brass fitting etc. Your idea sounds like it may take 1hour of labor opposed to several days like ACP's plan. Granted theirs may be safer but I don't think I will need that at this point in time for my Z.

mprowe350

Whosdaddy,
It is really easy if you want to cheat like I did and install prior to the rail. I took brass fittings and small brass pipe sections/ninty degree fitting to go from the brass T to the reg. No hoses needed but it does suck b/c I had to splice my factory fuel hose. I had originally installed with rubber hoses but they flexed too much for me to be coMfortable with. Although the return line is still rubber but wrapped with split tubing.

Most importantly we need to find something to plug the factory FPR. The aftermarket regulator will work before the rail if the stock FPR is plugged! Try the SARD type R it is a bit more money but it fits better and works well. I had taken pictures of the first setup I did w/ the rubber hoses to send to GQ but then changed to small brass piping instead. I need to take some more pictures this week and post them. One good thing so far is that I now maintain 51lbs of pressure or more.

MIKE

thawk408

iTrader: (16)

Sorry, but I am alittle confused. In this method does fuel come into one rail then crossing over to the other, and coming out into 2 lines? Or does fuel go into each rail seperately?

ACP

iTrader: (1)

Mike, You have been reading my posts right ?
I am making a fpr plug
Our 1st order is just for a dozen. About 8 are called for so far...

Also, at the same time, I am getting fuel rail adaptors made.
This will allow you to connect directly to the back of the fuel rail, with flex hose.

So for those that want to come off the fuel hardline, to a flex hose, then FPR, then to the fuel rail, can easly do so, and don't have to get into removing the fuel rails.

ACP

iTrader: (1)

While I am talking about tapping into the hardline, I mine as well post how I am doing mine, it is fairly simple.

There is a hard fuel line that brings fuel from the tank.
It comes up to the engine bay, shown in this picture below.
As it makes this turn and goes up, it turns into a smaller line, then is a connection to the hard rubber line. (that runs up to the stock damper rubber line in reference w/ stock damper )

Thanks to SKiDaZZLe help, he found a hardline fitting, that will connect to the fuel line, turn it into 6 AN fitting, to install high pressure flex hose.
To connect this fitting, you have to cut the stock fuel line.
I am going to cut it before it goes into the smaller hardline hose
-the small hardline looks like it might restrict
-the hardline fitting Michael found is for 3/8 size, which looks to be the size of the larger hard line hose
-will be easier to install this fitting where there is room. So I will be doing this, right around where you see the lines in the picture.

Will be doing this when I get back. Will post pictures

ACP

iTrader: (1)

Not sure if this your post is directed to me, but I am having two feeds come in, 2 out

With those that will be upgrading their fuel sytems in the next few months, they will find out they need to add a fpr, which is best to do so closest to the fuel rails.
Then I am sure some will use one feed (like the stock set up uses, as the fuel rails are connected)
And some that will run 2 feeds to the fuel lines, one to each side.

Will be nice to see this unfold, and see the different results