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Illegal Alien
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90% gasoline is a little different than 15%.
 

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DRS has done some E-85 tunes, they are awesome.
 

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My question is, what happens if you put E85 in with OEM everything?
Unless the vehicle is designed for E85, then it will run lean and eventually trigger a check engine code. Flex fuel vehicles use an ethanol content sensor or sometimes infer the ethanol content from the o2 & knock sensors in order to adjust for the E85.
 

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Illegal Alien
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Why, .. don't think we even have that much tuning control over the ECU yet....
 

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Actually the "magic" in an E85 tune is largely in the injectors. E85 has fewer BTU/Calories per gallon than Gasoline. More E85 must be dispensed to meet the same air to fuel ratio. However, E85 (with the right injectors) will work with a properly flashed stock ECU. Once again, contact DRS. Fred Zust runs an E85 tune on his Championship Frankenlotus. It is a rocket.
 

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Illegal Alien
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Right, but to tune to larger injectors we need more than base fuel trim tune capability, the fast works tune of OEM ecu is not yet available.
 

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In the owner's manual it says we can put E5 & E10 in our cars with no problem. My question is, what happens if you put E85 in with OEM everything?
Very broadly, your O2 sensors will see a lean condition, the fuel trims will add a whole bunch of fuel to get to E85's much richer Stoichiometric ratio, and you'll get much worse fuel economy. Very likely the fuel trims aren't broad enough to add enough fuel, so a CEL will happen saying something like "too lean", and the car may continue to run like crap. If you push the engine too hard before the fuel trims have sorted out, you run the risk of putting lean-burn holes in your pistons, or general ka-blamo. Just sayin'.

Some people like to trick the ECU into running E85 by dropping in injectors that have about 50% more flow rate. This doesn't panic the fuel trims as much.


Whether the engine and fuel system can tolerate E85 is a whole 'nother story though.
 

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Hmmm.. just reviewed DRS site info, about a year ago they will still running a piggyback ECU. I thought they had moved past that.
 

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You'll get a CEL until you burn off all the E85 & your car will run like crap...I tried it in another car. Unless you're tuned for it, it's like automotive cock block.
 

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There's factors which you may not aware of - a small factor is that ethanol needs to be relatively richer at full load than part load compared to gasoline, so a straight multiplier may not work. The big one is that E85 is 65-82% ethanol; it varies based on location and time or year. That's why OEs generally use a sensor.
 

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re: Ethanol

Ethanol and Methanol are great fuels, if you build and tune for them:

1. Remember all race cars used to run on Methanol.
2. Octane is 104. So more timing and compression.
3. It has oxygen, so you can burn more and hotter.
4. It significantly cools the air when it is vaporized in the intake manifold.

People have done E85 tunes ant it is like race gas... because it is!

One of the issues is that we buy gas by the gallon. Hence, one needs to know how much fuel is in the gallon, since gas and ethanol have different densities and how much heat that gallon can produce. It is OK to compare and price fuel by the gallon, if it is gasoline, but even diesel is different (it produces more energy). We should be paying per BTU, like natural gas to the house.
So this idea of selling fuel by the gallon and then introducing fuels with completely different energy densities and then varying the mix is like some perverted marketing trick.... But this is just a pricing issue.

The problems:

1. Vapor lock in the summer.
2. Water in the fuel in the winter.
3. Varying fuel mix at the pump. Then we need another sensor to see how much ethanol there is and how much fuel and advance it can take. This leads to a compromise solution in a multi-fuel engine. It it was race fuel, mixed to have same properties all the time, it would be much better.
4. Ethanol is corrosive to rubber, plastic, magnesium, aluminum (to some extent), etc...
5. The fuel system has to be bigger (pump, injectors, etc.).

Sp why sould anyone think of putting E85 into a car designed for gasoline? Why not diesel? or jet fuel? Same result. Your car was not designed for it. It will not work. It will detonate and damage your engine. And with E85 dissolve all the rubber in the fuel lines and plug the injectors!

If You really want tohave some fun, just add a little of nitro(methane). Like 5%. It does not need a re-tune. It brings its own oxygen..... :)

Anton
 

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2021 Evora GT
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I love this place!
 

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Illegal Alien
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Say, "Howdy" to Johhny Cace's for me! Used to dine there annually in my youth :)
Still in business, unfortunately Gerald Cace died a little over a year ago.
 
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