Thread: LPFP Tech info
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      01-09-2013, 02:43 AM   #85

Drives: '07 e92 AT Sport Montego Blue
Join Date: Sep 2011
Location: Portland, OR

iTrader: (3)

Originally Posted by ign335i View Post
Thanks for posting that data. It pretty much shows that this solution is inferior to a two pump parallel configuration and most likely a single E85 pump. Two questions:

1. Does the modified N54 engine need more fuel pressure or flow?

2.a. Assuming it needs more pressure, is the stock 72psi pressure limit exceeded with this setup?
2.b. Assuming it needs more flow, using your chart above, if the motor required a hypothetical 3GPM stock and now 6.0 GPM modified, what pressure can the series setup provide?

I am genuinely interested here. We talked about this before and its starting to become comical.
Only in a low restriction situation is parallel more efficient. So in both states, series out performs a single pump, so I'm not sure what you are looking at to make the assumption a single e85 pump is more efficient than a stock pump with an e85 pump in series? There is a point on the system curve based on a sliding restriction level that series and parallel perform at the same level, but still out perform a single pump. In our setup, parallel is not really an option without major modification. That's why series makes more sense even if the system has a low restriction.

I think you'll find that flow (volume) is required to support the HP level and demand the car is making on the fuel system at peak demands. So, run two pumps in series or increase the voltage and drive the single pump harder. We know the booster pump works, now it's only a matter of testing the replacement pump to see if upping table values will achieve your goals.

If you upgrade, keep is informed on how this are working out and what changes you needed to make.