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Thread: RAM 5.7L Hemi to Flex Fuel

  1. #1
    Potential Tuner ElecTape's Avatar
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    RAM 5.7L Hemi to Flex Fuel

    I would like to add the flexibility of running e85. I not looking to swap completely over to e85, but the ability to fill up with it when traveling and its available.

    Under Engine > Fuel > Flex Fuel there are several parameters for this. I am assuming that if I add say a Continental Flex Fuel sensor into the fuel line to provide (Temp and Percentage) to the ECU then this would be possible?

    If so...... Can the sensor be wired into the factory ECU (finding the appropriate pins), or would it just be simpler to convert the analog outputs to CAN and feed it into the CAN stream?

    Would one need any other sensors for this such as Fuel Pressure?

  2. #2
    Tuner vndetta79's Avatar
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    I'm interested to hear if anyone has setup flex fuel on these. I'm only starting to look into it.
    Not sure if you would gain much for the effort on an NA 5.7 unless the motor was built with high compression.
    You would mostly need bigger injectors to support it. The Fuel Injector Clinic website shows a good comparison of the required injector sizes for gasoline and E85 depend on your setup.

  3. #3
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    say what?

    the shit is 30% oxygenated. even if his 5.7 was 8:1 and didnt benifit from timing, the stuff makes its own air when ya burn it

    like nitro : )

    the 5.9 magnum in my 2000 dakota (9:1) loves a 50/50 blend of e85 and premium even with the stock tune and injectors

  4. #4
    Tuner vndetta79's Avatar
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    Quote Originally Posted by LilSick View Post
    say what?

    the shit is 30% oxygenated. even if his 5.7 was 8:1 and didnt benifit from timing, the stuff makes its own air when ya burn it

    like nitro : )

    the 5.9 magnum in my 2000 dakota (9:1) loves a 50/50 blend of e85 and premium even with the stock tune and injectors
    Wow, that's pretty cool. I honestly haven't notice enough of a gain with stock NA setups to warrant the extra fuel consumption. So now I have a question LilSick, if you run a 50/50 blend, what AFR's are you running the motor at and do you know what the ethanol content is? My guess is the AFR's would need to be around 12.2:1.

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    no idea

    truck has a direct connection pcm from 25 years ago (jtec)

    after running a couple tanks thru it maybe the trims compensated and its close?

    either that or it put the long term kr back in it i dunno but its happy. very

  6. #6
    Tuner vndetta79's Avatar
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    Quote Originally Posted by LilSick View Post
    no idea

    truck has a direct connection pcm from 25 years ago (jtec)

    after running a couple tanks thru it maybe the trims compensated and its close?

    either that or it put the long term kr back in it i dunno but its happy. very
    Thanks for the info.

  7. #7
    Potential Tuner ElecTape's Avatar
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    Well, there are a couple of kits that essentially have a pre-terminated Fuel Hose, Continental Ethanol Sensor, a jumper harness that goes between the factory injector harness and the injectors and to a controller. They also generally allow for a Bluetooth out or analog out so you can see the ethanol percentage while driving.

    I already know that I would need to increase the injector size and most likely go with a larger fuel pump or a dual pump system since I have other mods that will increase consumption.

    I'd just prefer to control it all thru the ECU now. Rather than to have to have a piggyback unit in the mix. It also saves some money to just add the sensor, rather than all the other junk.
    Last edited by ElecTape; 05-23-2023 at 01:44 PM.