AFPR hose diameter to the Fuel Rail

[SlimLim]

Hey guys,

I did a search and it doesn't have the answer i need. I bought a SARD AFPR with 8mm fittings.
I notice you guys use 3/8" hose in the AFPR kits.

Is it fine to use 5/16" hose to the fuel rail?

 

[supraguy@aol]

I used AN-6 on mine, which is equivalent to 3/8, but I would think 5/16 would be ok.

 

[MDCmotorsports]

-6 minimum.

 

[SlimLim]

Sorry to bring this up again, but why do you specify -6AN when the stock fuel hardpipe is 8mm which is closer to 5/16?

Is it for volume?

 

[figgie]

SlimLim

that is part of it.

the objective is to increase the volume delivered without increase to much the preeesure differential between the fuel pump and the fuel rail.

 

[jdub]

Something else to keep in mind...the line from the rail to the AFPR to the tank is the return
AN-6 is plenty big enough for this task without causing a restriction...the AFPR is the restriction (that's where you get the desired pressure).

If you want additional volume to the rail from the tank, it's a different line...the one that attaches to the FPD at the top rear of the fuel rail.

 

[SlimLim]

Ok i understand the operation of the afpr now.

So the return line is made larger than stock because at a certain point, the volume flowed will not change whilst the pressure will increase and so theres the restriction. Is this correct?

 

[jdub]

The purpose of the return line (through the AFPR) is to return fuel to the tank the engine does not use. The FRP is an intentional restriction in this line to control pressure in the rail....the J-tube is there on the stock set-up to provide a restriction in case the FPR fails and keep the motor running (though not very well).

You can use a larger line for the return if you wish..it will have no effect on rail pressure. The AFPR you plan on using controls that. When using an AFPR you want to remove the J-tube restriction by drilling it out or eliminating it completely.

 

[SlimLim]

Gotcha jdub. Thanks for the help fellas.