N54 Stock DME Flex Fuel

veer90

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Considering the DW400 has been tested and shows that it pulls more amperage than a W450 why do that when our pump control module is already at the limit with the W450? There's no real world performance improvement from the DW400 because the venturi limits both pump's max output anyhow.

If you are going full aftermarket fuel delivery, dumping the factory fuel lines and upgrading the EKP then the DW400 might be worth it. If not just stick to the standard because that makes everything else easier on the troubleshooting and tuning front. Everyone is familiar and can help you easily.

Let me put numbers around it. Precision Raceworks and @V8bait just made 650hp on a single Walbro 450 with this flexfuel setup on their live stream in front of a live video audience just last week.

I know Gilbert at euro tuning was testing the DW400 and I expressed the same concerns about the EKP. He reported no issues

650 wheel with a single 450 is pretty cool though.
 

Hill'n'toe

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Mar 12, 2018
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I'm just looking for some more HP, like 380. I don't really know how much boost that make.
For now no budget for high flow catted DPs..
Thanks anyway
 

dyezak

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I know Gilbert at euro tuning was testing the DW400 and I expressed the same concerns about the EKP. He reported no issues

650 wheel with a single 450 is pretty cool though.

Because amp draw is proportional to fuel demand I don't think anyone short of a track car (pushing the fuel pump at 100% duty cycle for extended amounts of time) would really see a problem with the EKP.

Most of us street guys, 1/4mi guys, or 1/2mi guys are pushing the EKP to 100% duty cycle for short stints....probably not going to really see a problem like that.

But great to hear first hand experience.
 

pysical

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For those of us who will be running PI. Does this add any complication? I thought PI is made to spray X amount of fuel at X amount of boost. So with MHD scaling the maps from 93 to e85, the PI will spray the same regardless of the octane rating. I read someone that someone tied a switch to the PI ground to turn off when they are running the 93 map. But now, since it is all automatic and no more map switching, how will the PI adjust to the amount of fuel needed for low octane such as almost pure 93, vs the full E85?
 

dyezak

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For those of us who will be running PI. Does this add any complication? I thought PI is made to spray X amount of fuel at X amount of boost. So with MHD scaling the maps from 93 to e85, the PI will spray the same regardless of the octane rating. I read someone that someone tied a switch to the PI ground to turn off when they are running the 93 map. But now, since it is all automatic and no more map switching, how will the PI adjust to the amount of fuel needed for low octane such as almost pure 93, vs the full E85?

This is covered somewhere in the previous 25 pages of info in this thread.
 

pysical

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Actually I found it using the "Threadmarks" on the top of the thread. I just purchased tuning from Twisted for my car. I think it might be worth waiting till Flex Fuel comes out fully before having him tune this then?
 
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dyezak

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I believe your tuner will just ramp in PI fueling when tuning AIC controller. My tuner has no problem tuning with it.

No, there is a custom AIC map that will be provided and the ECA will have an output to the AIC that will drive the E% interpolation. Again, for details it was covered previously in this thread.
 

pysical

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Jun 16, 2017
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So after reading about the PI scaling. It uses the TMAP wire on the AIC. If my AIC has the vacuum line for boost reference does that mean I need to get the newer one that uses the wire instead?
 

doublespaces

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Actually I found it using the "Threadmarks" on the top of the thread. I just purchased tuning from Twisted for my car. I think it might be worth waiting till Flex Fuel comes out fully before having him tune this then?

For big threads like this, hopefully the threadmarks will continue to be useful to some.
 

once-ler

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Sep 18, 2017
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Of the four options on the Motiv website for the Ethanol Content Sensor, the latter two are "Sensor + Engine Bay Short Line Upgrade" & "Sensor + Full Feed Line Upgrade"
  • What are the benefits of the Full Feed Line over the short line + stock hard line if one has upgraded turbos?
  • Are there any drawbacks of using the full line?
 

doublespaces

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Of the four options on the Motiv website for the Ethanol Content Sensor, the latter two are "Sensor + Engine Bay Short Line Upgrade" & "Sensor + Full Feed Line Upgrade"
  • What are the benefits of the Full Feed Line over the short line + stock hard line if one has upgraded turbos?
  • Are there any drawbacks of using the full line?
The full line upgrades the feed from the fuel tank forward. The short line only upgrades the feed from the firewall forward.
 

once-ler

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Sep 18, 2017
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The full line upgrades the feed from the fuel tank forward. The short line only upgrades the feed from the firewall forward.

I get that part. I was wondering what is the value is of purchasing the full line vs. reusing part of the stock line. For example, if the line material is different (e.g. more resistant to ethanol) or if it has a greater diameter (which could conceivably alter fuel flow or pressure for better or worse) vs. what is already stock on our cars, or if it's better to replace the lines on high mileage cars as a maintenance item etc.
 

dyezak

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I get that part. I was wondering what is the value is of purchasing the full line vs. reusing part of the stock line. For example, if the line material is different (e.g. more resistant to ethanol) or if it has a greater diameter (which could conceivably alter fuel flow or pressure for better or worse) vs. what is already stock on our cars, or if it's better to replace the lines on high mileage cars as a maintenance item etc.
Bigger diameter
 

fmorelli

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I don't believe anyone has actually answered @once-ler's question. I may know half the answer:
Full line: ethanol requires burning more fuel by volume. The larger line from the tank removes restriction, especially as one increases the percentage of ethanol in the gasoline.
Partial: no idea why someone would do this. The option exists so there must be a reason?

Filippo
 

Jake@MHD

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The majority of N54 owners have no need to replace the full line from tank up, so the short lines gives them the ability to easily add the ethanol sensor by just replacing the short piece up to hpfp.
 
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Jeffman

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The majority of N54 owners have no need to replace the full line from tank up, so the short lines gives them the ability to easily add the ethanol sensor by just replacing the short piece up to hpfp.
This is exactly what I'll be doing.
 
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