QUIET external low-pressure electric fuel pump?

RobbMc said
Very quiet and you don't need to change the rest of the fuel system:
http://www.robbmcperformance.com/products/powersurge.html

I read all of the information in that link. You are using a Walbro Pump for this?? The fuel system does need a regulator to operate correctly so the fuel system will need to be modified is what it says. I do understand that the return goes from the regulator back to your pump. It also says if you do not use a regulator with the pump and lower the fuel pressure the flow will be reduced by 50%. 50% of What???

Also there is NO Flow Data that I could find anywhere. It just say's this one for 500hp and this one for up to 1000Hp. Can you point us in that direction of the Data so anyone interested can know how much fuel these pumps actually flow?

Notes:
The PowerSurge must be used with a bypass (return style) regulator. However, the return line runs from the regulator to the PowerSurge, not back to the fuel tank.
Not recommended for use with methanol.
Made in the USA. We use only genuine Walbro electric fuel pumps.
Not recommended for applications requiring more than 65 psi (75 psi intermittent).
Requires the use of a factory 1/4" vapor return line.
The PowerSurge 500 can be later upgraded to a PowerSurge 1000 for $100

Thanks in Advance