I changed nothing to run e85. 1995 hoses, lines, pump, etc. However, I run a flex sensor and I switch back and forth between gas and e85 and the e85 is never left in the tank for extended periods of time. That's because I don't drive the car much and I'm afraid of the ethanol sitting in the tank all that time doing its best to absorb all the moisture it can out the the South Florida air. Maybe I'm just being stupid and listening to what everyone else says but it seems to make sense to me.

A question for the OP: how do you intend to deal with the varying ethanol content of pump e85? Do you know what the percentage is in the tank right now? I've gotten as little as e65 and as much as e85 from pumps in my area and SW Florida. Without a flex sensor, how do you intend to deal with this?

 

Between a deployment and a newborn, my car sat for 2 years with ethanol in the tank. 1/2 tank to be exact. It ran a little shitty when I got it going again, but not too awful. You could tell the fuel was old, but it still worked. I ran it down to about 1/8 a tank and put new in, and boom! We were in business.

Ethanol concentration varies by state and by season. (Winter months get more gasoline, straight E85 is a PITA to get to light off on stock coils in 30 degree weather). They divvy it up by classes. Then you get into the whole mixing pump thing and you never know what you're going to get. It leaves me having to retune before and after summer.

You just watch your AFRs and if it goes rich, you know. They also have this.

ECF-1 (FUEL) Ethanol Content & Air/Fuel Ratio Gauge

Or they have the cheap water test.

I recently got a gassy fill, and I was running 11:1 in boost. What a pain. That is why I am going with a flex fuel sensor, and a big reason I did a ECU upgrade.

 

I love my ECF-1 gauge. I can also confirm that the signal from one flex sensor can be shared between the gauge and megasquirt to avoid having to use the analog output from the gauge/into MS.

 

I've run E85 on stock lines for several years and never had a problem. I've converted 3 miatas and my daily driver g35. The only issue I've had was after turning the boost up on my Miata, my Walbro 255 couldn't keep up and got swapped out for a DW300.

The 2nd Miata I switched to E85 I datalogged driving to the gas station on 93 octane. Filled with E85, uploaded a tune with 35% more fuel, added 5 degrees of timing in boost, and datalogged again.

 

Just want to come back and say I gained about 3-4 mph on the back straight after the E85 switch. Car seems to run cooler as well.

 

What power/boost level did your walbro crap out at? Just wondering when i'll hit the wall myself.