Im replacing my 5/16 line and im running twin 255 walbros. will i be ok with 3/8 or should i run 1/2? Can i also use the 5/16 for the return for whichever i choose?

 

ive got a buddy running twin bosh pumps and hes running -8an (1/2") feeed and return and hes fine he makes 600 hp to the rear wheels,just make sure if you buy 1/2" hard line that you get it in id, most places measure it by od so 1/2" od is 3/8 id,i have a roll here of aluminum 5/8" hard line and it measures 1/2" inner diameter make note of that if you didn't already no, and i would at least make 1/2" the minimum size only do it once,i always over due my fuel systems so i can grow into them if needed!

 

I would STRONGLY recommend the same size return line as feed line. I had to learn this lesson the hard way.....

 

Ok what happened when you ran different size fuel and returns. This is my first fuel system to upgrade so im just trying to learn as much as possible before i tackle it.

 

I couldn't get fuel pressure low enough, had to run a pump bypass, which, when it came in, leaned me out and caused me to tulip 4 intake valves. When I went to the same size return as feed line, and removed the pump bypass, all is well.

 

Yea i definitely dont want that. Would you go with the twin 255's or 1 big pump?

 

Mine has a 5 gallon cell, on E85, and I'm running a BG 400 pump, track only, (at least for now....), so it's a whole different ballgame, I'll let somebody who knows more about those pumps in question chime in here.....

 

Need more info.

What fuel will you be running? What pressure? FI? Carb? How much power do you want to make? How much boost will you need to run to get there?

IMO if your redoing the fuel system anyway it doesn't cost much more to go with 1/2 so you might as well do it.

 

I have a 347 with a 72 mm turbo on 93 pump gas. Its fuel injected and its running out of fuel at the top of second.