Changing my Fuel Rail setup

**ls1camino** · 09-29-2011, 08:29 AM

I want to change over from the stock fuel setup (in-tank regulator) to an aftermarket regulator in the engine bay. I already have aftermarket rails installed and an Aeromotive regulator I picked up somewhere.

Here is a picture of the regulator:

Here is the best picture I have of my rail setup (crossover under the cowl):

I want to just junk the stock lines and run new 6AN or 8AN lines from the fuel tank to the engine bay. I'm confused as to how the regulator should be setup. There are 5 ports...the three big ones are for fuel and the small one on the front is for a pressure gauge, but what is the one on the red part for? Is that the vacuum line port? Do I need that if I'm not boosted? Do I just cap it off or leave it open? The port on the bottom is the outlet for the returnline to go back to the tank. Does the regulator have to be on the inlet side of the rails or the outlet side? I'm finding more compelling evidence that it should be on the outlet side of the rail, but I'm also finding people that have it on the inlet side of the rail. Is there any pros/cons to either setup, or are they same, and just personal preference?

What size lines would you suggest running for the supply and the return. Right now I'm N/A with a single Walbro 255. I obviously plan on upgrading to dual pumps and FI sometime in the future, so should I just go 8AN and not have to upgrade down the road, or should I just stick with 6AN for now and replace the lines when I upgrade the motor? 6AN or 4AN for the return line?

Thanks all

**cammed goat** · 09-29-2011, 09:47 AM

I am looking at an old issue of GMHTP with a story of a supercharged C6Z and there is a pic of the regulator that runs off a T fitting and is located in front of the master cylinder. The T fitting exits the front of the driver rail. I have never dealt with fuel systems, but I hope this gives you an idea. Especially since you stated that you might be headed down the FI road in the future. No mention of AN size unfortunately.

GMHTP "What Lies Beneath"
September 2009

**ls1camino** · 09-29-2011, 04:23 PM

Originally Posted by cammed goat

I am looking at an old issue of GMHTP with a story of a supercharged C6Z and there is a pic of the regulator that runs off a T fitting and is located in front of the master cylinder. The T fitting exits the front of the driver rail. I have never dealt with fuel systems, but I hope this gives you an idea. Especially since you stated that you might be headed down the FI road in the future. No mention of AN size unfortunately.

GMHTP "What Lies Beneath"
September 2009

Thanks Rich, that's what I want to do, bu I can't tell if that is on the outlet side of the fuel system or the inlet side. Can you?