TALLBOY
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- May 31, 2014
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Ok here goes. My truck has 205/50's from Holdersdiesel.
I found that not having a regulated return as of yet running a piggyback fuel pump is pointless. I installed a sump from FASS with a 6.4 pump in series. The psi continued to drop as always. I noticed having the pump installed did increase my idle psi but didn't help the WOT psi at all. So I figured the 6.4 pump was weak. So I replaced it. It continued to act the same with a better idle and psi at wot dropping. So then I came to the conclusion my 6.0 pump was bad. So I replaced it aswell. Did not help anything but maybe a 1 psi difference.
I called 2 freinds of mine Jay from PHP and Sam Evens that lives in Sc. We continued to exchange ideas. So the next bright idea I came up with was to try running the 6.0 pump in the 6.4 housing in series. So now I had 2 6.0 pumps in series. Helped a little but this also caused psi drop at WOT and was causing some fuel leaks in the fuel lines and the front pump housing couldn't handle it. Sam Bet me 20 bucks that if I ran the pumps in Parallel it wouldn't drop.
So I had to reconfigure my lines a good bit to line the 6.0 pumps in parallel. Now this worked Awesome. As soon as the psi starts to drop it jumps back to a full 60+ psi. The only reason the pumps will not work in series is because the back pump is a huge restriction on this setup. The blue spring works off the initial psi so it sets to that pressure. So if your running a R&R the series pumps work gret. However if you have a blue spring you have to run them in parallel to get the optimum psi that's needed. I hope this helps someone in need.
My setup is this. Sumped to both pumps with 1" supply line tee'd. the rear pump has a 1" feed line and the front I used a 3/8 feed line to increase velocity to the front pump then tee'd to the engine. I used the 6.4 pump housing with a 6.0 pump inside on the Rear and stock 6.0 housing and pump in the front.
I found that not having a regulated return as of yet running a piggyback fuel pump is pointless. I installed a sump from FASS with a 6.4 pump in series. The psi continued to drop as always. I noticed having the pump installed did increase my idle psi but didn't help the WOT psi at all. So I figured the 6.4 pump was weak. So I replaced it. It continued to act the same with a better idle and psi at wot dropping. So then I came to the conclusion my 6.0 pump was bad. So I replaced it aswell. Did not help anything but maybe a 1 psi difference.
I called 2 freinds of mine Jay from PHP and Sam Evens that lives in Sc. We continued to exchange ideas. So the next bright idea I came up with was to try running the 6.0 pump in the 6.4 housing in series. So now I had 2 6.0 pumps in series. Helped a little but this also caused psi drop at WOT and was causing some fuel leaks in the fuel lines and the front pump housing couldn't handle it. Sam Bet me 20 bucks that if I ran the pumps in Parallel it wouldn't drop.
So I had to reconfigure my lines a good bit to line the 6.0 pumps in parallel. Now this worked Awesome. As soon as the psi starts to drop it jumps back to a full 60+ psi. The only reason the pumps will not work in series is because the back pump is a huge restriction on this setup. The blue spring works off the initial psi so it sets to that pressure. So if your running a R&R the series pumps work gret. However if you have a blue spring you have to run them in parallel to get the optimum psi that's needed. I hope this helps someone in need.
My setup is this. Sumped to both pumps with 1" supply line tee'd. the rear pump has a 1" feed line and the front I used a 3/8 feed line to increase velocity to the front pump then tee'd to the engine. I used the 6.4 pump housing with a 6.0 pump inside on the Rear and stock 6.0 housing and pump in the front.
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