Sw20 fuel return line

[CJ]

Im currently upgrading my fuel system
Fuel feed is a 6AN and fits well.

Fuel return is where im coming unstuck.
The hardline on the tank is a 6mm.
I can get a 4AN-1/4 inch hardline fitting
Cant get 6AN to 1/4 inch hardline fitting.

I was pretty keen on keeping the fuel return 6AN to help it flow well.

Do i put a 4AN fitting on the tank hardline and then an adapter 4AN to 6AN which will eventually go to the pressure regulator?
OR am i wasting my time with 6AN because the tank hardline will bottleneck it anyway?

Will a 4AN line be too small from the regulator?

Thoughts?

[Jabeo]

Im gonna be doing a full full system overhaul soon, including the pump, rail, injectors etc preparing for an ecu upgrade. I did some research and i settled on the way that bob pham does his return lines using the stock tank hardlines. I will have a 6AN return line, with an AN to Barb fitting on the end, then join that fitting to the return using a piece of fuel hose clamped on each side to join the two. He has run his 400+ hp gen 4 track car like this on e85 for a long time and has never really seen an issue come up with it.

Here is the video, the whole video is worth a watch but skip to 17:30 for the part regarding connecting back to the fuel return hard line

[CJ]

Yea. I was trying to stay away from barb fittings.
Guess it wont be super high pressure though.
I'll look into that.

Ta

[GDII]

What's wrong with a barbed fitting? The OEM setup uses a little bead and a weak hose clamp. People running a Walbro 255L or similar don't have leaks or the return blowing off.

This is a clean setup. It uses a -4AN to 1/4" on the return and -6AN on the feed. Unless you are replacing the WHOLE return line to the tank with a -6AN then you are wasting time and money with larger hoses and fitting upstream.
https://www.instagram.com/p/CKdYfGHMAmZ/

Unless there is data supporting your power goals/fuel flow that the 1/4" return is not big enough then just leave it. I'm sure Charlies 500hp monster still uses the OEM hardline for the return.

[tw2]

I deadheaded my rail and used this kit with FPR https://wilhelmraceworks.com/fuel-system

Simple and easy. The stock return is fine for anything other than insane hp. I am NA but I have a walbro 255 installed, no issues.

[Benckj]

Yea. I was trying to stay away from barb fittings.
Guess it wont be super high pressure though.
I'll look into that.

Return line should not have any pressure on it as its open ended into tank. I used a better flexible 4AN size hose with dual clamps on each end but fittings are simply flared. Supply is completely different and needs to be pressure rated. Largest restriction is the S bend that connects tank hardline to filter. Unlike others I cut off the hardlines at pump bulkhead and installed flexible & removal hoses at that point. This allowed a reduction in fittings and restrictive areas plus using a hatch for pump access (never drop tank again).

[CJ]

Cheers guys.
Thats all pretry much answered my questions.

The fuel return wont be under too much pressure. I'll run it as -6 from regulator back to tank hardline and use barb 1/4 inch connection.

The feed line remains stock hardline from pump/tank as far as the engine firewall. Then becomes -6 all the way through. That S bend has been deleted (jim).

Cheers