After doing a few weeks worth of research on the topic I came to the conclusion that with a couple bucks, a free Saturday morning, and a visit to my tuner, I could have my S2000 set up to run E85 flex fuel. I'd have the flexibility of running E85 when available and 93 octane when it wasn't, as well as any mix of the two. The main goal is to realize a higher power potential with an E85 tune, but not chain myself to a less-available fuel source or worry about a mix of fuel types being incompatible with a straight E85 or 93 octane tune. Also it is something extremely interesting to me and somewhat unique within our community.

Many FI users have strict E85/93 octane setups where essentially a toggle switch controls what tune they use, but the availability of the Ethanol content sensors and aftermarket ECU suppliers integrating this capability into their softwares has made flex fuel a pretty simple option now.

The main problem with doing something like this is the unfortunate limited supply of alternative fuels within the state of North Carolina. When I checked last week, the Alternative Fuels Data Center was only reporting nine gas stations in the entire state of NC that carry E85. NINE in the entire state!!! There are more than that in the city of Greenville, SC alone! The state of SC seems to be much more accepting and welcoming to alternative fuels, and I can only assume that it has something to do with fuel taxation laws. So good on ya, SC. Luckily for me, one of the nine stations in NC is five minutes from my work, just a little further from my house, and basically on the way to most of my autox sites. Here's to hoping they stay in business for a looong time.

I'm very excited to get this underway and start installing. Basically all I needed was a standard GM flex fuel sensor, an analyzer unit which takes the digital pulsed signal from the sensor and breaks it down into analog voltage signals that feed to my ECU, and a pair of fittings to adapt our 1/4" fuel return hose to the sensor inlet/outlet. My existing setup already included aftermarket injectors, fuel pump, pressure regulator, and ECU to make it all work.

I'll update as I get stuff in and done. For now, piece one of the puzzle is here with more pieces on their way.

 

Cool. Still need that ride.

 

this is badass!

 

That's a slick concept. We're spoiled in sc when it comes to fuel options. You Han get 100 octane around town.

 

I lucked out and found some seemingly nice adapters that convert the EFI fittings on the sensor over to appropriately sized hose barb fittings for the stock fuel return line. They were only $6 for the pair! My ethanol content analyzer should be here on Monday which would be the last physical piece I need for the install. Unfortunately I think I have to go out of town next week for work, ugh.

 

Sweet!

 

ECA came in today, and its pouring down rain here which means no yard work for me this evening. With any luck I may have everything wrapped up sooner than I thought.

 

Got the stock fuel return line out, bought new 1/4" 100 PSI line, installed the sensor onto the line, and got the return line back in the car. Checked for leaks and everything seems to be OK. Put my fuel pressure gauge back on my rail and saw that my fuel pressure was up a few PSI from what I remember (I set it at 45 last time, it was around 48-49 yesterday). Not sure if that is an effect of the sensor/new return line, but I lowered it back down to 45 PSI. Car idled fine on the jack stands.

Now to get all the wiring done and verify that the Haltech ECU is interpreting the signal correctly.

 

This is so badass. I love the idea of being able to run any combination of both fuels and benefitting accordingly. I'll be building this into my system when I boost

 

Ahem.