Understanding Return Style Fuel Systems

[Irishman]

subscribing. I will be installing my return system after my motor breakin, hopefully in the next few weeks.

 

[JoshK]

I am going to give this thread a bump as I still don't exactly understand the different ways to setup up the regulator on a return system(pre or post rail). I have purchased a Fore triple pump returnless system and am planning to use it in return systle configuration. I am wondering which way to set up the regulator and rails. I have been looking at either the Fore F1i regulator that has two ports or the F4i that has 4 ports. I still need to buy a regulator so if I don't need to spend the extra cash on the F4i for the additional ports, I won't.

 

[JeremyH]

Here is the most common way done with a two port regulator post rails and what Fore reccommends for the average setup. Also another diffrence betwen the f1 and f4i is the f4i has 10an ports where the others have 8an ports.

 

[908ssp]

There a few ways of doing it. Often packaging dictates which way you have to go. My preference if I can have it is to go in one end of one fuel rail over to the other fuel rail and then to the regulator and back to the tank. This allows continuous fuel flow through both rails. Which should keep the fuel at a more constant and cooler temperature. The pressure doesn't change anyway you choose to run it.

The above drawing is very good and has similar advantages it just uses more fittings and hose.

 

[JeremyH]

And here is a 2 port setup run pre rails, not as popular as you have more of a chance for a pressure diffrential the farther away from the regulator you get on the supply side.

 

[JoshK]

So what would the 4 port setup be like, and is there a benefit of one over the other?

 

[JeremyH]

And here is a "pump to a dead head" method where it dead ends at the rails similiar to the way the new cobrajet is setup. This requires a 4 port regulator.

 

[Greg Hazlett]

^^ what is the benefit to that setup?

 

[JeremyH]

It seems this dead head metod with a 4port may put the least amount of heat in the fuel compared to a traditional dead head method with a 2port where the regulator is run more like a bypass. There are also other ways to do it these are just some of the more common methods. I would also stay away from a daisy chain method where you run the rails in series to/from the regulator instead of parallel, while it works a parallel setup will insure equal pressure and flow at both rails.

 

[JoshK]

Would this be the daisy chain method that you are referring to? These are two ways I was thinking of doing it, but do like the way you have it in post 43

Both of these configurations should be possible with an F1i regulator as it has two -8 feed ports and one -8 return port, correct?

 

[JeremyH]

Correct that first pic is a daisy chain style and both would work that second pic would yield higher fuel temps.

 

[JoshK]

Why would the second pic yeild higher temps? They are both a deadhead setup, the second pic just Tee-s the line before the rails instead of doing a daisy chain.

 

[JeremyH]

Compared to a through style 2 port setup. Ie fore does not reccommend a dead head setup with that regulator.

 

[JoshK]

I'm sorry, I'm still not following you here. So you are saying that both of the images I posted will net higher temps even though both of them return the fuel before it goes through the rails. Both of the images I posted would be with a F1i regulator.

 

[JeremyH]

Correct. I ruled out the daisy chain setup period and compared your 2nd pic.

 

[Flapjack]

Sorry, never really revisited this thread after I finished everything up.

Everything works great with the dead-head style shown in post #47, which was also recommended by Lethal. I'm running gasoline now, so the triple pump system I have is way overkill, but it's nice to know it's there.

As for fuel temps, as Lito stated, if you don't look at it you probably won't worry. I don't look monitor it and have never had a problem. I guess ignorance is bliss.

I couldn't stand the fuel pump running with they key on, so I did install a kill switch and put it in the cup holder (under the cup "spacer", or whatever the hell you call it). Pictures below:

 

[JoshK]

Which regulator did you use Flapjack

 

[05stroker]

Here is the most common way done with a two port regulator post rails and what Fore reccommends for the average setup. Also another diffrence betwen the f1 and f4i is the f4i has 10an ports where the others have 8an ports.

I used to have the dead head setup or the Cobra Jet setup and now have the setup here we will call diagram one. It was recommended to me by LITO and that was all I needed.


The thing I like about this and the deadhead setup is that both rails see the same amount of fuel till it sees the regulator.

I know the rail to rail and then to the regulator has been done forever and works but if something happens and the is fuel starvation the the first rail wood fair better the the second.

 

[JeremyH]

Thats the way Fore reccommends as well with their 2 port regulator and thats how I would do it if I was running a return setup. A pass through parallel style setup is my preference for a street driven car as well.

 

[JoshK]

Okay guys, I think I have it now. I believe I will get a Fore F1i regulator and set it up just like the diagram that is now known as diagram 1.