How does it flow fuel for 700+hp? Your are feeding a surge tank from the factory gas tank using a Walbro or stock fuel pump. The fuel is then feed from the surge tank to the rails using the Bosche 044 pump. Won't the 044 outflow the Walbro leaving the surge tank empty at some point. I don't understand exactly how this works because your still feeding a larger pump via a smaller one unless this has to do with pressure in some way. What is the point of the surge tank? Couldn't you run the pump inline without another smaller tank? Someone chime in please.

 

I think the walbro can keep up because it is not pumping under nearly as much pressure to the surge tank as it would be normally. Less pressure = more volume. The bosch pump then operates at system pressure.

At least this is my understanding of it.

 

i have only stage 1... so not 100% on this but isnt it a fuel return system so the fuel gets pump in a loop with both pumps in it.. so basically it will pump as hard as the 044

 

I was under the impression that a return fuel system was for consistent flow and adjusting pressure via the regulator.

 

that's correct. the walbro in the tank is pumping fuel at essentially 0 zero pressure to the surge tank. at 0 pressure, a walbro 255 has about the saem output as a BOsch 044 at 43 psi of fuel pressure.

 

Careful with starvation issues during sustained runs... BamBam and Sharif had issues getting the AAM st.2 system to hold up over a sustained run due to the bosch pulling fuel out of the surge tank faster than the walbro could keep it filled. I believe the "trick" to get everything to hold up was to over-cycle the walbro. Basically, a boost-a-pump solution for the smaller pump... Again, Bam and Sharif would have all of the details, but as I understood it - the st.2 is good for short spurts and quick pulls on the dyno, but be weary of trying to hold WOT for anything longer than a few seconds.