Yesterday I put a -6 fuel line from the filter to the IP. I made the kit myself using braided hose and fittings. Seems like it helped some as the pressure is 15-16 at idle, and only fell to 5 psi @ WOT with the J W/ A was turned up to 5. Pretty soon I am going to disconnect factory LP and go with a Holley or something else since I do have a new VP44. Should I have gone with -8? Just wondering what most people that are running an fittings with braided line are doing.

 

-6 is sufficient for most applications, use -8 for big power (it has over 75% more flow capacity).

 

-6 is plenty with a VP.

 

what lines do u change im lost

 

fuel supply from tank to LP, then LP to Filter, then Filter to IP.

 

At what point do you need to go bigger that the stock 3/8 line?

 

3/8 line is enough for 500hp, easy.

I went with -8 anyway

 

its not really the 3/8" thats the problem its the banjo bolts........use metric to JIC fittings in place of those and loose the hardline to the IP and your waaay ahead of the game. and I used 1/2" as well just because I can. I built my own plumbing system with the fass. its a little awkward at the filter housing and injection pump though

 

Thing of it is, 3/8 (same as -6) is still bigger than the fitting to get into the injection pump on a VP so it will ultimately be the final restriction in the game here. My walbro fittings are smaller than 3/8 but bigger than 5/16 (metric somewhere in between) and I feel like I flow enough fuel to support 500+ easy. I have it set to 18 warm idle and I never ever see it under 16 no matter how hard I run the truck with whatever load I can put behind it.

 

I will get some pictures of mine later, but all I have so far is from the filter to the VP. I plan on doing th whole system though, and doing away with the banjo bolts. I used 90* an fittings coming off the fuel filter and into the VP. It definitely seems to help as sometimes at idle I can see as much as 16 psi, 12-13 at 60 mph, and 5 @ WOT with the J w/ A set on 5 5. I mainly keep it on 3 5 and so far have not seen it go below 8, so I think just doing that has helped.