Which would be better and why:
1, A surge tank with high output pump(s) that would be fed by return fuel from the engine, with an overflow line returning to the main tank, and feed line teeing into the stock supply. The pump or pumps would only run at WOT, and rely on the stock pump's check valve.
2, A surge tank fed directly by the stock in-tank, with one pump running always, and maybe a second pump coming on at WOT. There would be four operational lines, a supply and return from the main tank, and a supply and return from the engine.

 

My setup is similar to your option 1 and is working well. Out of boost I am running off an almost stock bucket.....just the intank regulator(returnless) has been removed and blocked off. In my bucket the reg just plugged into the top of the filter. The venturi siphon system is still functional to keep the bucket filled. In boost the Magnafuel 750 kicks in. Return from the rails fills the 3 gal surge tank, overflow goes back to the main tank. I also have a separate vent line from the surge to the highest point in the main tank. I had issues until I added this. You could just vent externally, but I kept the evap system functional. Both pumps feed into a Y through check valves. The main feed line runs from the Y to the rails.

I like the reliability of running off a fully functional OE module most of the time. Not sure of the long term consequences of running the stock high pressure pump as a low pressure lift pump in option 2. Plus, then you have at least 2 pumps running at all times.

 

Why this over a couple of 450 pumps ?

 

I've already been through two different bucket-butchering configurations. Both needed a 1/4 full tank to work, and a minimum 1/2 full fuel tank to absolutely guarantee no fuel flow interruptions. I want a system that works as worry-free as the stock system does.

 

Makes sense. I bent a rod in a 6.0 once when my second walbro came on at an eighth of a tank so I can relate. I just keep half tank or no boosting until I do something more serious.

 

Is the surge tank fed from the main tank or only from the fuel rail return?

Is that sufficient for hi HP?

 

X's surge tank is fed by the fuel rail return. At three gallons, it will feed about 1 zillion horsepower for like 85 seconds. It is sized to not run out of fuel as long as he expects to keep the throttle wide open. When he lets off the gas, the pumps in the surge tank shut off, and the surge tank refills from the return. 3 gallons is a lot.

 

I have been reading on this a lot recently. There aren't very many pictures of setups in these trucks. I put the dual pumps in the tank and cut the bucket up. I want to add a surge tank before I have to deal with fuel starving. I was thinking of feeding a 1-2 gallon tank with an in-tank Aeromotive 340 from the main tank. The surge tank will feed the fuel rails the return from the rails will go to the surge tank and an overflow from the surge tank to the main tank. The surge tank itself will have an in-tank Aeromotive 340 as well or I will put a big inline/external pump, but don't want to deal wit the noise either lol!

Is anyone else running theirs like this? Thoughts?

 

I thought of runing -8AN line from the tank using bulkhead fitting into inline fuel pump and filter then tee it to the fuel rail. This inline pump will turned on using hobb switch.

I have not seen any surge tank fittment to a truck. Where best place for the surge tank? under the truck or in aux battery location?

I like the idea of the surge tank as it will resolve the issue of fuel starvation at 1/4 tank and WOT.

 

85 sec is about right. An 11 sec run would only draw about .5 gal from the surge tank with my ID 1000 injectors runing at 100% duty cycle. They max out at around 85%, so less than .5 gal. Having used the factory pump to drain the main tank via the return line into a bucket, I can see that it takes a while to refill the surge, so the extra capacity is a safety factor in case you are doing back to back blasts. 2 gal probably would have been sufficient. Of course the Magnafuel 750 pump will drain the entire 3 gal in that time period. All this fuel gets heated up passing through the rails and back to the tank. So the bigger the surge tank, the less the fuel in the tank will be heated. If the tank was only 1 gal, the entire contents would pass through the rails 3 times during a run.