Flex fuel question

Kenjermen

900 HP Club (N54)
Nov 6, 2016
259
78
35
N las vegas NV
hey everyone,

I am currently running a Haltech to control boost and other stuff. I am looking into getting the mad flex fuel kit and was wondering if I need it to also plug into the Haltech side as well? The position of the flex fuel sensor is different from the MHD version where the Haltech wants it on the return line and mad wants it on the feed. Or will I just need to run to separate sensors?
 

langsbr

Captain
Apr 5, 2017
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07 335i 6MT e90
I thought you would need to run a boost box to have it control boost if you aren't using stock wastegates or solenoids. That allows the dme to natively control boost. Can the haltech accept the dme signal?
 

dyezak

Major
May 4, 2017
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Plano TX
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Haltech is very uncommon. I would contact your tuner for the best answer. And bring the info back here to share so others in the future can search and find the information!
 

Kenjermen

900 HP Club (N54)
Nov 6, 2016
259
78
35
N las vegas NV
I thought you would need to run a boost box to have it control boost if you aren't using stock wastegates or solenoids. That allows the dme to natively control boost. Can the haltech accept the dme signal?
The haltech taps off of signals going into the dme but it controls the MAC solenoid for the boost, you would set a target for the dme so it doesn't freak out but other then that boost is controlled through the haltech
 

langsbr

Captain
Apr 5, 2017
1,189
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07 335i 6MT e90
If boost is controlled explicitly by the haltech, then I would think flex fuel won't work completely for you, since the DME should be manipulating target boost based on the interpolation of the ethanol content.
 

Kenjermen

900 HP Club (N54)
Nov 6, 2016
259
78
35
N las vegas NV
If boost is controlled explicitly by the haltech, then I would think flex fuel won't work completely for you, since the DME should be manipulating target boost based on the interpolation of the ethanol content.
The haltech has flex fuel capability I just couldn't run it due to the flex fuel also makes timing and fueling corrections
 

LamboLover

Corporal
Apr 6, 2017
237
242
0
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Everything
Not used Haltech for 9 years and almost certainly not your model, but if you want the Haltech to adjust boost based on ethanol content you could take the analog output from the Motiv analyzer and also connect it to the Haltech or connect the ethanol content sensor itself to the Haltech and the Motiv analyzer if the Haltech is able to connect directly to the sensor. In this case I would not want the Haltech input with a pull up enabled and it would then simply read the frequency of the open collector sensor that is pulled up to what I believe is 5V in the Motiv analyzer. It really depends how configurable your Haltech is, but these are your electrical options with a typical standalone in this setup.
 
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