I'm about to convert to E85 myself. From all the reserach I've done, you only need to upgrade the pump, injectors, and retune. I'll be running either an E85 or 93 oct map, switching with my laptop as needed.

 

How do you know what you are getting? Do they mark the filling station with the eth. level? like regular pumps? I am really thinking of changing to this because I currently run 93 + 100% meth and am starting to do more road racing. The meth makes me nervous every time I drive. I have a station right outside my neighborhood with Ethanol but I want to know that I am getting 85 and not some winter blend. BTW I would have AMS tune me to run it. Can I just ask the gas station? I'm sure the attendant has zero clue.

 

I would think the only way is to switch tunes....have 2 tunes...one for winter blend and one for summer...I also doubt that the attendant would know about the blend...with me I will be watching my logs when I think its time for a blend change,,,and switch tunes when needed.

I could not think of any other way around it.

 

Thats the problem.. the exact blend isn't marked and the attendants are always clueless (I've actually asked numerous times). I haven't seen anyone talk about this. Lots of people have posted about running E85 but not much on experiences buying it from the pump at a gas station.

 

My Evo hibernates in the winter so I shouldn't be as prone to the winter blend. I would just like to know that I am getting the 85 and not the 70. I would think the 70 would throw my tune way off. I will be flashing the oem ecu.

 

I'm guessing even a 70% ethanol blend would yield an octane rating well over anything at the pump...maybe somewhere between 95 and 98. Until E85 blends become more mainstream and people absolutely know what they're pumping into the tank I'd say play it safe and go with a 70% ethanol tune. Of course that means you'll have to find some winter blend in order to tune with in the first place, but once that happens it should yield much more power than typical premium pump fuel. If only the Cali based enviro-***** would bring this over. It seems like it would be right up their alley. Not sure why Oregon's tree-huggers beat us to the punch but hopefully it's only a matter of time in CA.

 

Not quite that easy though, because with the higher ethanol content of the summer blend you need more fuel, so you will run lean if you tune for 70%.

 

I think the only way is to have a wideband and tinker with the maps all the time.. Unless someone can find a fuel alcohol sensor and wire it into an EMS

 

Vishu tuned an Evo with E85 and made somewhere in 350hp with minor mods. There was a news article about it. You should ask them

 

pretty sure the Vishnu car was just a tune on E85 without consideration for the blends.. at least he didn't say anything about it.

I found out Megasquirt actually handles this. GM makes a fuel composition sensor that sells for $350 that sits along the fuel line and sends a signal for 0-100% ethanol. Megasquirt uses fuel and ignition trims based on that to be really "flex fuel" (any blend of ethanol). Info here: http://www.megamanual.com/flexfuel.htm

I checked out the AEM EMS and it looks like it will do fuel trims based on the sensor just fine with the user defined fuel trim table but doesnt seem to have a way to do an ignition trim. I think the signal would need to be converted to 0-5v

not sure about other aftermarket ECU's

Might be better to have fuel/ignition maps for 0% ethanol and maps for 85% or 100% ethanol and then interpolate between them based on the sensor.. Maybe some day something can be done with the extra map space in the stock ECU.

 

There is one station in california that sells e85 to the public and it locatied in san diego