secondary fuel for twin turbo v6

[SSE 4 2SS]

Originally Posted by MagnumForceGB

My plan was to have a second fuel pump supply just the aux fuel system and a controller for it........

Originally Posted by bowtieracer

Magnum yes you are correct controlling the fuel is the key....

Please bare in mind I’m not terribly familiar with the V-6 fuel systems...

I’ll toss this in the mix... I’m twin turbo and we ran into fueling problems... at 12 or so lbs of boost, we were losing pressure at the fuel rails. I believe you are dealing with DFI as your primary system and are looking to supplement this as boost climbs into higher amounts.

We had the Lingenfelter dual fuel pumps in the tank bucket. We also had a BAP. We killed two birds with one stone on our next stage of development. I used a die grinder and removed the false wheel well in the trunk. We moved the battery up and forward. I plated over the cutout opening. We then built a frame and a “sump.” This sump is a ~~3 gallon tank. We purchased a Weldon external marine grade fuel pump and filter housings. We looped the fuel feed from the tank, via the Lingenfelter pumps, with them running at high speed with little to no back pressure into the sump. Excess fuel when the sump is full spills back to the tank.

We eventually outgrew the single Weldon and added an additional pump in parallel. We run these on a Weldon FPCM.

Now... when we turn the key, the Lingenfelters come on running in high speed as mentioned. This supplies fuel to the sump... the primary Weldon (Weldon1) comes on at slow speed to supply the fuel rails at 58-60 psi. Weldon1 pulls fuel from the sump tank only. A -10 line comes off the Weldon. At 1 PSI of boost, a hob switch closes and Weldon1 kicks into high speed run mode. As Boost increases, a boost sense regulator keeps things equal relative.

The second Weldon pump (Weldon2) has a suction pickup in the factory tank, on the same plate as the existing fuel pump.

With Weldon1 in high speed, we are fine on pressure and volume until about 18 psi. For safety sake, we selected a 12 PSI switch to kick start Weldon2. This pump comes on and only runs in high speed. This pump also has a -10 discharge port. We Siamese the two lines together into a -12 headed to the rails. At the back of the motor as the fuel line enters the engine bay, we “Y” the -12 back into 2 ea -10 with one going to each rail. At the head of the rail, the -10’s again Siamese and then go to the boost sense regulator.

Again, I’m not familiar with the fuel systems of the V-6 engines, but possibly something in here can maybe get you outside any walls you might have run up against.. if you are talking about a stand-alone fuel system as an add on, then the sump, and external fuel pump can solve that. Run a separate fuel line forward, solenoids or rails for the additional injectors, a regulator and possibly there you go... you would have to run two pumps, one to fill and return the sump, and the pump pulling off the sump.

The sump supply can be smaller as it will keep the sump full and you only go into high boost for short periods of time... I burn 5 gallons in a one mile pass, and the sump is only three, but the Lingenfelter duals are running wide open at all times, and the second Weldon pulls straight off the factory tank...

I know it’s complicated but it works and it’s not all that bad if you see it...