Re: dead head or bypass. I think bypass is a better system for the street. With a properly set up regulator. Its ALL in the regulator. If the pump is up to the task for the injectors, the tank is properly baffled and sumped, the pick up is at the right location (below main tank, at sump level) and the lines are of sufficient size. It all comes down to the regulator. If its not giving consistent pressures and flow to the injectors you will have problems with consistency for HP and torque and drivability on the street..
A dead head system will over heat the pump in a street car. Its cavitating and pumping within itself. Trying to make its own bleed off, so it pumps back into itself, back into the tank as cavitation.
With a bypass system the regulator is the dead head. It should be coupled with a pump that can supply it with enough pressure to keep it on full regulation. So then it can bleed off the necessary fuel to the injectors and still bleed of the remainder back to the tank. But it needs to be operating at a full pressure (from the pump) so its at full head pressure all the times. So in essence its like a dead head system, locking the pressure, its determined pressure, at all times for the injectors. The advantage is it will still allow fuel flow when its at peak pressure.
A fluid pump needs to have some flow, even at max pressure, its what cools them. No fans. Take a look at a high pressure washer, the better pumps have a bleed. That bleed cools the pump.
A dead head fuel system works fine for a race system. Only short races, some races may last what a hour or two (Thats long). Not like a street car that needs to last years under stopped traffic and not much demand.. Unless you pack a spare pump and tools for every ride
Im thinking a bypass fuel delivery system for a fuel injected car is the best. Not like the days of carburetors and mechanical pumps where a dead head system works fine. Low pressures and remember, they are pulling fuel (mech pumps) not pushing it, big diff.
JR