Needing help picking out fuel lines for my Fi Set up

Just got my complete Holley Sniper X Flow set up for my 70 Charger RT from FASTMAN, just waiting on my Distributor. He recommended 3/8 hardlines front and back as I’m running an in tank pump. So I’m wondering can SS factory bent main line work and also for my return or do I need to do something different? Any help would be appreciated. Thanks!

I don't know how much power you plan on making (or E85?)? I use my old stainless steel 3/8" feed line as a return line, I bent a new feed line out of regular 3/8" steel tube. Has worked well with my fuel injection with an intank pump

You can use the factory line for most of it. Cut off the flared ends and use a -6 a/n adapter (uses a crush type internal collet). Or just weld on the fittings.

I prefer to use teflon hose for the flexible connections as you don't get any fuel vapor smell from it. (and generally smaller outer diameter and looks nicer, in my opinion)

OK thanks. I have a Stainless Steel feed line so that’s good. I’ll just order another SS feed line and order some Teflon hose and some fittings. I’m pushing close to 600 HP and don’t plan on running E85. Thanks!

Depends which fuel pump module that you are using. If you use the Holley muscle car module then you don't need a return line. Holley makes a 350 LPH internal pump module which supports 700+ hp and it doesn't need a return line since the return is in the tank. It also doesn't need a regulator since the regulator is in the tank. Just hook up your existing line to the new pump and you're good to go.

https://www.holley.com/products/fue...umps/muscle_car_efi_modules/parts/12-384

Well for some reason FASTMAN has got me using this pump https://www.holley.com/products/fuel_systems/fuel_tanks/parts/19-168 That pump you’re showing me looks like it could have saved me some work.

That 350 lph drop in pump is brand new, I think it's only been out a month or so. Previously the options were a 255 lph drop in pump, or the 400 lph module that also requires the fuel tank to be modified or a replacement tank installed with that sending unit interface on it.

The higher the tank-mounted pump pressure (modern factory FI is 43.5 psi, or 3 bar), the smaller the feed line can be.
As pressure increases, flow through a fixed line ID increases as the square root of the change. Double the psi raises the flow by 41% (2^.5 = 1.414).

Yes, if you have a stock gas tank then the drop in 350 LPH module is the slick way to go. If you have already installed your fuel pump then the question is which regulator you have. If you have an older style billet regulator you put it up front and run full length feed and return lines. If you buy a Holley 12-876 regulator/filter combo then you can put it at the rear of the car with a very short return line. Then you just have one high pressure feed line going to the front. I've plumbed a few cars with the 12-876 and it works pretty good with a 600 to 700 hp engine. https://www.holley.com/products/fue...s/regulators/efi_regulators/parts/12-876

I ordered an EFi tank with the pump already installed from Holley, all from FASTMAN.I emailed Richard about the 350 pump, waiting for a reply. He sent me this regulator https://www.holley.com/products/fue...lters/filters/efi_filters/parts/162-554. I’m a newb when it comes to EFi but if this 350 pump will work it will save me a lot of work. If there’s a reason he didn’t want me to use it that’s fine also.

Rich got back with me and he highly recommended me using a return line so I’m going with his advise. Thanks guys!

I'll be running OE 3/8 SS line from the tank to engine compartment with E85 on my Barracuda. Hardline + limited restricted fittings, that's a ton of fuel you can move.

Holley has been coming out with a ton of good products lately, but that pump just looks so cheap I have a hard time getting over it. Love how it has everything compressed to one unit tho.

I am a firm believer in a return set up from front to back, I also have found I had to insulate all my fuel lines & the pressure regulator from heat,if not it heats up the fuel in the tank, I drive my car a lot & its hot here in Southeast Tx , , I have the Tanks Inc 450lph pump & tank. I

What did you use to insulate the lines and regulator with?

That’s the lines I’ll use and I’m going to use the pump that FASTMAN recommended.

That is my preference as well.

Regulating inside the tank works of course but doesn't compensate for any pressure drop across the feed line/fittings. So with in tank regulation, you can see pressure drop slightly with higher fuel demands even if it's within the normal capacity of the pump.

I believe teflon lines use their own AN fittings just as a note. I wish I had gone that route. I went with standard braided and once the ethanol eats thru it, I'll have to redo with all new fittings to go Teflon.

I like the Goodridge 910 hose/fittings fwiw. Lots of flexibility and easy to work with.

If you used the adapters and a return line could you tell me how many adapters you used?

I used the factory style hard line, Hemi sized 3/8 supply and bought a regular BB/SB 5/16 line for the return and ran them side by side. I flared the factory line with the GM push-on style o-ring fittings and bought the appropriate adapters. For example Russell Performance 644133.
AG.

General rule of thumb is that the return line should be no less than the diameter of the feed line.

I agree100% !!!!! but others will say you can use 1/4 in return

Yes I guess that would be me

Used a 1/4 return on a twin turbo 70 malibu with a 255lph walbro pump for years.

I think the general rule of thumb applies more to carburetor setups that are trying to regulate down to 6psi. Hasn't been an issue for me with efi pressures.

On EFI applications the return fuel is under little to no pressure compared to the supply so it can tolerate a smaller line. I wouldn't push my luck though on a 1/4" line though.

EDIT - Also, with some EFI setups you can PWM control the pump so you may have very little return flow so that makes running a smaller line way more feasible.
AG.

Rich recommended a 3/8 return line but now I’m trying to figure out if I can use my Rev N Nator or not. Rich says he’s never even heard of one lol. I bought the hyperspark distributor. He said I should be good using my firecore wires and coil.

Does it have a points in connection? When the Sniper controls the timing the control works thru the white wire which connects to the points in connection on the ignition box. MSD and Holley ignition boxes have spot to connect the points output. If you have that on your box then you are good to go. Either look at the box or look at the instructions.

Correct. If the EFI pump is sized correctly then the return line should not have much pressure in it so it can be smaller. All the EFI cars that I've plumbed lately have used a regulator in the trunk (race cars) or the regulator is in the tank (street cars) so I don't use a return line anymore. The OEM guys don't use return lines.

The Rev N Nator uses a factory style box and plug in just like original with the ballistor. If my box won’t work can I do away with the Ballistor and just use MSD 6 Al and which model number 6al do I get and matching coil or The Holley ignition Box with Firecore coil?. What ignition set up do you recommend as I couldn’t get a clear answer from Rich. He must be a busy man and didn’t reply to my last email. I just need to get this stuff ordered. Thanks!!!

The Rev N Nator is a replacement MP style ECU that requires the magnetic pickup distributor to work, the Holley won't be able to control it unfortunately if you're looking to control timing from the Holley.

I'm researching this stuff myself, I already have a 6AL and Blaster II coil, was going to use the points output from the Holley to drive the MSD box. If I were you since you need to replace everything and already bought the Hyperspark distributor, I'd buy the matching Hyperspark CDI box and coil. You won't have a ballast resistor in line with the 12v feed to the coil anymore.

https://www.holley.com/products/fue...er_efi/hyperspark_ignition/parts/556-151
https://www.holley.com/products/fue...er_efi/hyperspark_ignition/parts/556-152

Thanks for that advice! I just had somebody to tell me almost the same thing but they told me to use the Holley Ignition box but use the firecore coil as they thought it was the better coil.

under little to no pressure compared to the supply so it can tolerate a smaller line

Backward. Low pressure requires a larger line (like voltage vs. gauge size). The reason the smaller line works is low volume, not low pressure.

I agree with that. If you already have MSD stuff then keep it but if you're buying new then I'd go with the Holley Hyperspark ignition box. The MSD boxes cost more because they have extra features such as rev limiter chips but you don't need any of that stuff when you are using the Sniper since it is all built in.

[Isn't this also because all the OEM's are PWM now as well? If you're not running a PWM pump and no return from the rail/forward regulator, sounds like a recipe for short pump life.

Ok I’ll buy the Holley stuff. Any recommendations for spark plugs with this set up and I’m done with this thread. Thanks to everyone for the help.

Plugs depend on which head you have and what the compression ratio is. I use NGK 6987 on all my street builds but I also always use a Trick Flow head. I haven't used a cast iron head for more than 30 years so no idea what plug would work with them.

Im running the Trick Flow 240. Thanks again!!!

Then the 6987 should work for you. Those are a wide gap, extra projected nose plug. They are OEM fitment on several newer cars and are usually around $3 each from Summit or NGK direct.

That’s great, thanks again!