The pump you require depends on the boost you run. At 2.5bar your pump will need to be efficient at 2.5 + 3.5 bar = 87psi. Most are out of puff at this. Also the fuel you use is mega important the bsfc of pump is .6 change to Methanol & its 1.2 meaning twice the fuel needs to be pumped Race Fuel is around .9 meaning 50% more required. This is a subject I have studied. I was going to write a tech article on Pump/Injector choice at high boost its very interesting.