EFI fuel line set up

[MarkAM]

I haven't spent much time posting messages on the forum but, after reviewing a number of threads, I can tell it is very helpful.

Question...I just finished installing the flexible lines and fuel pressure regulator provided by FFR in my Blueprint 347 fuel injected Roadster. The fuel pressure has a return port on the bottom side which I ran back to the fuel tank using the flexible lines provided by FFR. Is it best to hook it up this way and block off the return port on the engine fuel rail or should I use the return port on the rail and bypass the regulator (blocking off the bottom port on the regulator)? My engine should arrive next week but I am just trying to plan ahead. Thanks in advance for your help.

[phileas_fogg]

Which EFI system are you using?

The Holley systems with which I am familiar are plumbed differently from what you describe. High pressure goes from the tank to the input of the fuel rail. The output of the fuel rail goes to one of the side ports on the fuel pressure regulator (it typically doesn't matter which side). The output of the FPR (bottom port) returns to the tank. Take a look at Figure 1 on Page 3 here: https://documents.holley.com/199r10653rev10.pdf.


John

[TMartinLVNV]

To tag on to what John said...

If you are using the Holley Sniper FI, their manual recommends nothing smaller than 3/8" for both send and return lines. This includes everything from the hanger bracket in the tank, to the motor. The Holley also uses an internal regulator, so the external one is not used. The return line hooks directly up to the passenger side of the throttle body.

This a gripe with me because I purchased the $500 option through F5 and only ended up using the fuel pump. The rest of the kit I could not use in order to comply with the Holley requirements for my 347.

Hanger - Several people have modified their existing hanger to hook up with 3/8" lines. Or, you can purchase the Pro-M unit ($$$).

Lines - The return line for the F5 setup is 1/4" I think. This may make a restriction and cause problems with your fuel injectors. Replace with 3/8" for both send and return.

[MarkAM]

Thanks guys. I am using a Holly Sniper FI system provided by Blueprint Engines. I spoke with FFR a couple weeks ago regarding the 1/4” return line and they said it would not be a problem since very little fuel is returned to the tank. I am using the fuel pressure regulator with a pressure gauge just to monitor the pressure from my in-tank pump. I assume I can run the 1/4” line straight from the fuel rail to the tank and simply plug the return port on the fuel pressure regulator provided by FFR...correct?

[Papa]

With the Sniper, run your feed line and return lines directly off the ports on the Sniper. No separate regulator is needed since the Sniper has one built-in.

There are three fuel inlet options on the Sniper. The return comes directly off the built-in regulator. See page 4 of the Sniper Quick Start guide:

https://documents.holley.com/199r11193.pdf

[TMartinLVNV]

Don't use the F5 supplied regulator at all. Install one of these directly before the throttle body inlet:
Earls AT100199ERL Ano-Tuff Fuel... https://www.amazon.com/dp/B006YH2JBG...p_mob_ap_share

Verify the hose size. This part is for 3/8" line. The return line will come directly off of the throttle body. The gauge you already have can screw in there.

This is your car. But be aware that you are following general directions from F5 who did not make your throttle body and going against the instructions of Holley ($1000 part).

[BradCraig]

I'm surprised FF is saying 1/4 is adequate for return. For the Sniper to operate properly, you need to follow the Holley directions and requirements. 3/8 supply and return is a must.

[Papa]

I'm surprised FF is saying 1/4 is adequate for return. For the Sniper to operate properly, you need to follow the Holley directions and requirements. 3/8 supply and return is a must.

This is correct. You need 3/8 lines for feed and return. I used -6AN (3/8" ID) braided flex lines for both. I won't be tracking my car, but if you plan to, check the regulations. Most tracks require that you have no more than 12" TOTAL flexible fuel line. Do you plan to run an internal or external pump? I recommend internal and you can get a pump hanger that has 3/8" inlet and outlet and then -6AN fittings to go from the hanger in/out to whatever -6AN lines you want to use.

[nick7405]

This is correct. You need 3/8 lines for feed and return. I used -6AN (3/8" ID) braded flex lines for both. I won't be tracking my car, but if you plan to, check the regulations. Most tracks require that you have no more than 12" TOTAL flexible fuel line. Do you plan to run an internal or external pump? I recommend internal and you can get a pump hanger that has 3/8" inlet and outlet and then -6AN fittings to go from the hanger in/out to whatever -6AN lines you want to use.

Last few years they might have changed it but it's less than 12 inches of rubber hose...not flexible. You are allowed to have your whole system SS braided or pushlok if it's the rightmaterial.

[MarkAM]

Thanks everyone. Based on the input, I will remove the FFR provided regulator and just run lines direct from the throttle body to the tank. Much easier and probably will save a headache somewhere down the line.

[BradCraig]

Yeah, Sniper runs well if you install per directions. I have one on my Camaro and love it. Below is a compilation of gotchas I have compiled over quite a bit of time helping others with poorly running Snipers. This was done for a Sniper FB group so some points may not be applicable here.

Brad Craig – 1/1/20
Here's the deal...The biggest complaint I have about the Sniper (or any of them) is they market as plug-n-play and 100% self-learning! They aren't!
Few points:
• Your current setup better be rock solid meaning if your engine is tired and running like ****, Sniper will not fix that. Exhaust leaks? Better fix those first, a very small leak will drive the O2 sensor nuts. If your electrical system is a rat’s nest? Forget it. Basically, any current issue you have will be magnified by any EFI system.
• Gas Tank: You can use your current tank with external pump and run a return line or use one of the return-less options. I chose the Tanks, inc EFI tank with in-tank pump because its honestly the best way to do it. New baffled tank to help prevent sloshing and loss of fuel pressure, quieter pump, longer pump life, and the constant recirculation keeps the fuel charge cooler. If you use your tank, pull it and flush the crap out of it. Note that Sniper recommends\requires a minimum of 3/8 supply line. They also recommend 3/8 return, but I used the existing 5/16 as my return without issue as do many.
• O2 sensor\Exhaust: As stated, NO EXHAUST LEAKS AHEAD OF THE SENSOR! Do not use the provided clamp in the kit, weld the bung in and pay attention to the angle
• Electrical: +/- must be run directly to the battery no exceptions. Another 12v hot during cranking\running must also be provided, this must be a clean circuit! Holley does not say it, but best thing to do is to run this feed to the battery + with a relay and trigger it via the 12v hot. Good connections a must here.
• RFI: this is the largest thing that nails people and causes the Sniper to have major issues. Keep your sniper wiring away from the coil, alternator wires, spark plug wires, etc. You’ll also find you will more than likely have to replace your exiting spark plug wires with the recommended Holley wires that offer more RFI suppression. Some folks also find that their magnetic pickup disti causes RFI. That was not my experience however I went to the HyperSpark will hall effect to eliminate the possibility and to be able to control timing with Sniper (this is where it gets fun)
• Skills: This is a whole new skillset. You can set up via the provided handheld, but if you really want to tune it via Laptop so if you know your way around a laptop you are a step ahead. Read up on EFI basics and how it works. I see carb folks trying to make parallels to carbs and they get frustrated quickly. As a few folks stated, there is a FB group with a LOT of resources to help tune, many for free.
• Read the full manual….three times. The quickstart guide is ****, download the full install manual from Holley.
• Do not order your kit from Summit, Jegs, Holley, etc. Several other vendors will provide unbelievable support through the ordering and install process. Trust me on this.
• Have fun!!!! When you get it working right it’s a whole new car and you’ve taught yourself a new skill!

Hope this helps!

[Papa]

Last few years they might have changed it but it's less than 12 inches of rubber hose...not flexible. You are allowed to have your whole system SS braided or pushlok if it's the rightmaterial.

Thanks for the clarification.

Dave

[Pat427]

Dave,

This post has me a little perturbed.

I used the FF supplied lines for both my send and return lines. I believe the 5/16th were for the send and 1/4 for the return. Are you saying that I need to replace my fuel lines with 3/8th?

This is correct. You need 3/8 lines for feed and return. I used -6AN (3/8" ID) braided flex lines for both. I won't be tracking my car, but if you plan to, check the regulations. Most tracks require that you have no more than 12" TOTAL flexible fuel line. Do you plan to run an internal or external pump? I recommend internal and you can get a pump hanger that has 3/8" inlet and outlet and then -6AN fittings to go from the hanger in/out to whatever -6AN lines you want to use.

[Papa]

Dave,

This post has me a little perturbed.

I used the FF supplied lines for both my send and return lines. I believe the 5/16th were for the send and 1/4 for the return. Are you saying that I need to replace my fuel lines with 3/8th?

The Sniper calls for 3/8" lines and with the beastly 427 you're running, I'd think that would be desired. If in doubt, see how it runs with what you have and step up if you start having problems.

Dave