fuel return hose

[ercp98]

Hi,
I need to know if I can use a regular fuel hose for the
return line coming from the FPR? The fuel hose I am looking at is only rated for 50psi.

Does the fuel return "rubber" hose need to be rated for fuel injection also?

Thanks in advance.

example fuel hose: GATES 27004 3/8" x 25' (50 psi, 24 in/hg) Fuel Line/PCV/EEC Hose

 

[GSTwithPSI]

Depends? How much fuel pressure are you intending to run? If stock ~37psi, then yes. If over 50psi, then obviously, no.

Ideally, you'd probably want to use a upgraded lines and AN fittings, especially for a performance application. If you're repairing/replacing the stock line then it's not really needed, IMO. A rubber line rated for fuel and a hose clamp will work just fine.

 

[ercp98]

hi,
i have -6 braided lines from tank to fuel rail to FPR.

the fuel hose i was asking about is the rubber fuel hose from the FPR to the fuel return line to the tank
and the rubber hose that connects the steel return line to the fuel tank.

i am in the process of replacing these rubber lines.

Do these rubber hose need to be fuel injected rated? rated for greater than 50 psi?

 

[CutlassJim]

No they are under very low pressure.

 

[GSTwithPSI]

Yes, you can use a rubber line from the FPR to the steel return line. I'm not sure what type of connection you have leaving your FPR, but the steel return line is a 5/16" nipple IIRC. So, assuming you have a 5/16" nipple leaving the return side of the regulator, you'll be fine with a single piece of hose. There should be significantly less pressure in the return hose than on the supply side. This is the reason the return is only hose clamped even on a stock car, whereas the stock supply line is a high pressure clamped hose with banjo fittings.

From the stock hard line to tank, you need an adapter fitting. The stock fitting is 14x1.5 inverted flare, so you're going to have a hard time finding a rubber line that mirrors the stock one. Most people use a 14x1.5 inverted flare to -6 AN, and convert the pump hangar.

The only reason you'd need line that exceeds a 50psi pressure rating is if you intend on running 50psi or more of fuel pressure. On the return side of the system, you shouldn't be seeing those kinds of pressures.


</font><blockquote><font class="small">Quoting GSTwithPSI:</font><hr />

For anyone trying to adapt a AN line to the stock hard line here’s how you do it. You MUST have an inverted flare adapter fitting. I got mine from RCI, but they are available other places. If you aren’t familiar with what im talking about, just know if you do not have the correct fitting, the line will leak and sh*t can catch on fire. That should be enough to deter anyone from screwing the wrong fitting on. See here for a good read on some of the incorrect fittings that are used: click
Notice the flared center inside of this fitting. I included a few shots of the progression of installation from the stock hard line to the finished product with the -6 AN line installed.

<hr /></blockquote><font class="post">


click

 

[ercp98]

thank you for all the replies.

to clarify also, i am replacing the return fuel line with 3/8 metal fuel line.
that is why i have a 3/8 fuel hose as an example.

 

[CutlassJim]

Quoting GSTwithPSI:
Yes, you can use a rubber line from the FPR to the steel return line. I'm not sure what type of connection you have leaving your FPR, but the steel return line is a 5/16" nipple IIRC. So, assuming you have a 5/16" nipple leaving the return side of the regulator, you'll be fine with a single piece of hose. There should be significantly less pressure in the return hose than on the supply side. This is the reason the return is only hose clamped even on a stock car, whereas the stock supply line is a high pressure clamped hose with banjo fittings.

From the stock hard line to tank, you need an adapter fitting. The stock fitting is 14x1.5 inverted flare, so you're going to have a hard time finding a rubber line that mirrors the stock one. Most people use a 14x1.5 inverted flare to -6 AN, and convert the pump hangar.

The only reason you'd need line that exceeds a 50psi pressure rating is if you intend on running 50psi or more of fuel pressure. On the return side of the system, you shouldn't be seeing those kinds of pressures.




Dude are you even reading his posts? He just said he has -6 braided line from the tank to the rail and he's just replacing the return hose from the FPR to the factory hard line and from that line in the back to the fuel pump housing.

And he would absolutely need hose rated at more than 50psi if he was putting it on the feed side. 14 lbs of boost on stock fuel pressure is 51 lbs. And if you have an adjustable FPR and are only running 37psi base pressure then you're doing it wrong.

 

[GSTwithPSI]

Everything I said was in reference to the return side, minus the hose with 14x1.5 inverted flares on both ends. That was more of an FYI.

Like I said, the line from the FPR to the metal return line is just a rubber hose on a stock car. The same configuration will work fine with an AFPR. The hose is under low pressure, and is 5/16". Likewise, the factory line between the fuel tank and stock hard line is a standard rubber hose, also under low pressure. Since the OP is replacing the stock return line with 3/8" metal fuel line, he has multiple options he can use to adapt a hose on both the FPR and pump ends of his new hardline.

And he's not asking about hose on the feed side, so no, he shouldn't need uber pressure line.

...Curious as to why running 37psi on an AFPR is doing it wrong?

 

[tektic]

Stock pressure on a 1G manual with the hose OFF should be 37psi. On a 1G auto and N/T it should be 43psi with the hose OFF.
1G MT = 37psi
1G A/T = 43psi
1G NT = 48psi
All 2G turbo cars are 43psi also.

 

[CutlassJim]

Quoting GSTwithPSI:
Everything I said was in reference to the return side, minus the hose with 14x1.5 inverted flares on both ends. That was more of an FYI.

Like I said, the line from the FPR to the metal return line is just a rubber hose on a stock car. The same configuration will work fine with an AFPR. The hose is under low pressure, and is 5/16". Likewise, the factory line between the fuel tank and stock hard line is a standard rubber hose, also under low pressure. Since the OP is replacing the stock return line with 3/8" metal fuel line, he has multiple options he can use to adapt a hose on both the FPR and pump ends of his new hardline.

And he's not asking about hose on the feed side, so no, he shouldn't need uber pressure line.

...Curious as to why running 37psi on an AFPR is doing it wrong?



Everything after your first paragraph had nothing to do with his question so I'm not sure why you included it.

Getting an ADJUSTALBE fuel pressure regulator and not using it to ADJUST fuel pressure seems slightly moot to me (adjustable cam gears anyone?) That coupled with the fact that the stock pressure of 37.5 psi is below the industry standard of 43.5psi(3bar) makes me wonder why you would want keep it that low and handicap yourself when every fuel system component on the market is designed around a minimum of 43.5psi. So many good things happen when you raise base fuel pressure the only reason to have a limit on it is if your pump can't keep up or you're at the point you blow open your injectors. 60psi base pressure FTW!

 

[marvinmadman]

Lol

 

[GSTwithPSI]

Quoting CutlassJim:
Everything after your first paragraph had nothing to do with his question so I'm not sure why you included it.



I'm not sure if we're reading the same thread. My first paragraph addresses the question verbatim:

Quoting ercp98:
hi,
i have -6 braided lines from tank to fuel rail to FPR.

the fuel hose i was asking about is the rubber fuel hose from the FPR to the fuel return line to the tank

Quoting GSTwithPSI:
Yes, you can use a rubber line from the FPR to the steel return line....







Quoting CutlassJim:
Getting an ADJUSTALBE fuel pressure regulator and not using it to ADJUST fuel pressure seems slightly moot to me (adjustable cam gears anyone?) That coupled with the fact that the stock pressure of 37.5 psi is below the industry standard of 43.5psi(3bar) makes me wonder why you would want keep it that low and handicap yourself when every fuel system component on the market is designed around a minimum of 43.5psi. So many good things happen when you raise base fuel pressure the only reason to have a limit on it is if your pump can't keep up or you're at the point you blow open your injectors. 60psi base pressure FTW!
I don't install an AFPR for the sole purpose of adjusting fuel pressure.



Nobody I know installs an AFPR solely to adjust fuel pressure. I do it so I can keep fuel pressure consistent when I upgrade fuel components, namely the pump. If I could keep a consistent 37psi +1:1 bump with boost on the stock regulator, I'd have no need for an AFPR. As soon as you upgrade the pump, it overruns the stock regulator, hence the need for an adjustable version to keep pressure consistent at the rail. The only way I can see running 37psi handicapping you is if you're running out of injector and need to bump your pressure. At that point, I'd just upgrade the injector rather than run 60psi of base pressure, but that's just me. Everyone has their own opinion and likes to do things certain ways.

I'd say the majority of tunes I've seen work around stock fuel pressures (whether it be 37 or 43psi). I think most guys find it easier to tune around this, especially on cars that get driven on the street. Again, there's no right or wrong here (IMO), just personal preference.

 

[slugsgomoo]

To some extent, don't most pumps tend to drop volume as pressure increases as well? So in theory if you have a 1:1 rising rate AFPR in theory if you have no issue running the lower pressure at idle, which would be an idle quality issue due to spray pattern, not quantity anyway- 37+25 = 63psi vs running the 43 & being at 69 (

) psi

 

[CutlassJim]

If you have link adjusting your tune for more base fuel pressure takes about 3 seconds.

If you have the ability to adjust your fuel pressure and make it so that your injectors flow more, run less duty cycle, have a better spray pattern and you choose not to then I'm confused as to the point of why you are modifying a car in the first place.

You do you though.

Actual pressure with 15 in/hg vacuum on a 43 psi base is only like 36 psi so most pumps will be flowing a sh*t ton at this level.