Thread: LPFP Tech info
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      01-21-2013, 04:46 PM   #168
Second Lieutenant

Drives: 335i e92
Join Date: Nov 2012
Location: CA

iTrader: (3)

Originally Posted by PUIVIA View Post
Ok so once you get downstream (up?) of the tank you can't flow more than what the injection system allows? Why all this sudden need for excess flow? I thought the reason for upgrading the pump was because the pressure drops out.
Why is the pressure dropping? Because there isn't enough flow out of the stock setup. If you are increasing horsepower you are increasing air flow which means you need to increase fuel flow to hit your lambdas. None of this requires you to need more pressure. The pressure is dropping at these flow rates because the stock pump has hit a flow wall.

Originally Posted by kentgbr View Post
More current drawn by the same pump means more power wasted as heat in its electric motor. It is nowhere close to 100% efficient at converting electric energy into mechanical energy.
I think Tony knows the fuel is receiving heat. The point is it is such a miniscule amount that you probably wouldn't even be able to measure a difference in temperature.