running 2 fuels pump is just waste your money. The flow is just as one, running 2 doesn't mean it gonna double the flow. i personally like in tank than inline.If you wanna get your car crazy rich and crazy fuel pressure, get fuel pressure regulator and raise it to 60+ psi.
and wont changing the fuel pressure change the spray patten and atomization of the fuel?? i dont know myself, but iv read a little about it, but thats another potential problem for another thread...
why do you want 2 fuel pumps? what mods require such a drastic change in fuel supply?
explain what your trying to acheive and why then maybe people will be able to answer you with an answer your looking for
well, you need a new tank, about 2lt should do [?], with that you run a hi-flow, low-pressure pump to pump fuel from the main tank to the surge tank. the surge tank needs to be "over flowing" 24/7, with the overflow running back into the main tank. this is what eliminates the fuel starvation.
from the surge tank you just run the normal 75 fuel system to the engine, stock lines and stock pump would be fine. you can run the return line into the surge tank too, but if you work out the flow rates of the pump and lines you might not need to touch that side of the fuel system [less work].
i dont see why there wouldnt be a universal kit for something like this on ebay. just make sure you use top quality fuel fittings and lines.
i dont know how you would put extra fittings on the stock tank, but i would get it done by a boiler maker who can pressure test anything thats added for leaks.
iv never done this, and iv never had surging issues, but iv got a 3lt so the tank is in the boot, and i believe they have slush baffles to stop starvation? maybe this would be the better direction to go with?
Don't all 75s have 2 fuel pumps? The US Milano has the tank in the trunk but over the rear wheels, similar to my Alfetta. My Spica injected Alfetta tank is over the rear axle, is baffled and has sort of a cup formed in the center of the tank as a small reservoir. A metal line draws fuel from the bottom of the cup to a bung on one end. A line connects there to gravity feed fuel to the pump. Is this the same as jazig.k means by having a "3lt so the tank is in the boot"? Although I believe the Bosch injected Milano has an aux. pump in the tank and a main pump under the car.
does your car have the tank in the floor?
there should be an auxiliary submerged pump in the tank and then the main pump and filter under the car.
on my spider there is a stepped diameter rubber tube which joins the auxiliary pump outlet to fixed metal plumbing which exits the tank and connects to more tubing (fuel line) to the main pump. This has been known to crack and allow the induction of air to the main pump when the fuel level gets low or during cornering.
sounds like your symptoms. the picture i have is rough but shows the in-tank pump mounted vertically with a transition to horizontal plumbing which exits the side of the tank. Could the in-tank pump be bad and on hills the main pump cannot lift enough fuel. The pumps are designed to push, not to lift. Or even just the transition connection inside the tank could be split.
pretty sure the 044 is the common pump for a vl turbo upgrade and 'max out' at around 550hp, not 700 like claimed, if used in a single setup. still, 550hp is beyond the power your making [unless your holding out on engine details, lol ].
but, do you need a new pump anyway? is your still good? i guess a new one wont hurt it regardless. it might fix your issue, but i dont think its the pump.
also, if you upgrade the pump, i imagin you'll need an adjustable fuel pressure reg? iv never done this so i might be wrong, but you dont want to run too high pressure, and a new upgraded pump might just do that if combined with the original pressure regulator.
if someone who knows could comfirm my thoughts, that'd be great, because im thinking of upgrading shortly too [my pumps make some noises, and dont hold fuel to the engine if left a few days].