What needs to be done for an E85 conversion on a 2006 Dodge Charger? What are some things about e85 that i should be concerned about?

Wanting to centri charge a 426 stroker 6.1 based hemi. Aiming for boost between 10-15 lbs or whatever gets me between 800-900 hp. Curious about an E85 conversion to prevent pre detonation. I know the AFR is different and i will undoubtedly have worse mpg. I live in Texas where HEB is everywhere so E85 wont be hard to find. What thing should i consider before committing to E85? How long does it usually take for E85 to turn into jelly? Will E85 burn up catalytic converters or have any effect on 02 sensors? Is it worth it in the first place? What fuel system components will need to be changed? And is tuning for E85 difficult?

2 Answers

  • 4 years ago
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    E85 fuel can have as little as 51% ethanol (etOH) in it by law and still be called and sold as "E85". One big concern you should have is not tuning the engine to run on higher-octane-rated 85% etOH because if you get a batch of 51%% etOH fuel that fuel will be less resistant to knock than the 83-85% etOH mixture and you could grenade the engine if it's not tuned to handle the lower octane rating. The octane rating difference between 51% etOH fuel and 83-85% etOH fuel can be as large as a 103 octane rating for the 51% mixture and a 113 octane rating for the 83-85% ethanol mix, so tune accordingly.

    Also, come fully to terms with how terrible your fuel mileage is going to be by running on E85 fuel before you decide to make the transition. My guess is you'll probably see ~7-10mpg regularly if running on E85 in a motor modified to anywhere near the level you plan. Yes E85 is really cheap, but needing to fill up with fuel every ~150 miles or so will get old in a hurry so be prepared for the possibility of terrible fuel efficiency and very limited cruising range if you make the switch.

    That said when it comes to making big power, E85 essentially has a (leaded) race-gas octane level, so you can really tune an engine to take advantage of that and make big power that's simply not possible on regular pump gas if that's your thing, so have fun if you make the switch. Good luck.

  • 4 years ago

    Apparently E85 is not necessarily 85% alcohol, it can vary depending upon the season and may have more gasoline in the winter for easier starting. It has 73% to 83% of the energy of gasoline (according to a US govt chart), therefore lower mpg and you would need to use more of it than gasoline to get the same power. Alcohol burns cleanly (CO2 and water vapor), so it should not adversely affect catalytic converters. What can affect cats is too rich of a mixture (like when the diaphragm in the fuel pressure regulator of my old truck blew and was sucking raw fuel in through the vacuum line, making the spark plugs black/sooty and plugging up the cats).

    The chart does not really break out E85 separately, but mentions it under Ethanol/E100, so I don't know if E85 would have a pump octane rating close to 110 or somewhat lower compared with 84-93 for Gasoline/E10. Flash points and autoignition points are much higher for alcohol vs. gasoline.

    By now the rubber parts in car engines should be able to withstand alcohol, since at least 10% is added to most gasoline and many engines are specifically rated to run on E85. Not sure exactly how you would tune an engine when E85 alcohol/gasoline ratio is variable at different times of the year.

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