The 460lph Walbro fuel pump has become the benchmark go to product for anyone running large demand fuel system that requires an in tank pump.
The only draw back to the pump is its 75psi internal pressure release valve. That is, once the pump line pressure reaches 75psi, it starts to bleed off fuel delivery to maintain this maximum pressure.
While 75psi may sound like PLENTY of fuel pressure, think of this. If you were running 40psi base pressure, and a forced induction engine with 35psi of boost, you are not at the bleed off pressure of this pump. If you have smaller injectors and were trying to squeeze a bit more out of them and run say 50psi of base pressure, you're now down to running 25psi of boost before the valve starts leaking. In this day and age of E85 turbo cars, 25psi is nothing!
So whats the solution? Walbro have now released a 125psi version of this pump, which means these issues are a thing of the pump.