[dirtbkr89]

I have a fast direct port ez efi kit and i am curious on the way to plumb it. I have my new in tank pickup with 1/2 feed and return, in line fuel pump, fuel filter, regulator, fuel rails . What the proper way for doing fuel rails and return line?? I'm new to efi

[krisr]

In series like in that pic where you feed 1 rail, crosses over then out the other rail to the pressure regulator works fine. You can also feed them in parallel where you have a Y or T fitting to feed the front of the rails and out the back of each rail you plumb into the regulator. But if you've already got it setup in series like in the picture then no need to over complicate it.

This may help - http://www.megamanual.com/v22manual/minj.htm#supply

[HWYSTR455]

As krisr stated, but will add, in high HP or blown configs, it makes sense to use the 'Y' fitting method. Regulator on the end of the rails after feed from supply line.

Filters are pre, before the pump, per pump manufacturer's recommendations, usually 100 micron, after, usually 10 micron.

.

[Ollie]

This is what Holley recommends.

[HWYSTR455]

Ah, they base it on injection size, which makes sense.

.

[Tom Vaught]

"Parallel system" is always best as the last injector on a "series system" can sometimes "see" a different fuel pressure in the rail vs the "parallel system" due to restrictions in the hose/connections and the pulsation of the fuel pressure regulator at the end of the "series" set-up.

Lot of the OEM stuff will feed to the center of the fuel rail and not use a return at all.
They control the fuel pressure with the computer and the fuel pump controls. That makes the least "mis-distribution" of the proper fuel to the injectors.

The "Parallel System" is a good way to do it once and be done with it, as with boost and/or EFI you will always want more power down the road.

Tom V.

[dirtbkr89]

Found this diagram. Kinda what I was thinking pretty simple only difference is I'm running 8an line

[krisr]

That would work fine. I've personally tried most setups, the parallel system is definitely by far the best way to do it if you're aiming for a decent amount of power or using a boost referenced regulator but since my car is a street car (400 w/Butler E-Heads) I settled for simplicity and wanted something OEM'ish so grabbed a fuel pot from a VE Holden/Pontiac G8 where the fuel system is completely in tank (pump and regulator) and it only has 1 feed line to the rails, the rails are connected with a T at the rear and the front of the rail is plugged so it's a "dead head" system. I've run my car like this for a bit and it works fine with no issues at all like vapour lock, priming etc... These late model Holden/Pontiac's with this same fuel setup with 6.0's out here net around 500-550rwhp with a DW or Walbro pump swap.