FlexFuel sensor?
 

So I have been intersted in running E85 (when I get boost and big injectors ) but the closest station is 30mins away. Not really great for daily driving.

Was looking into dual tanks/pumps for the seperate fuels, but with a return type fuel wasn't sure that would work.
But then found out while researching that ms2 and ms3 can use a flexfuel sensor to adjust timing and fuel amount.

Anyone have any experince with this on a miata? Might be a good option for people who track near e85 sources, but do not have access for daily driving. And it seems way easier than dual tanks.

Use the regular wideband sensor. Tune for 12.0 during boost, NEVER under 11.5. Tune for 16.5-17 during cruise. 13.5-14 for spoolup.

If you plan on filling up once every week, E85 wont be a problem. If you drive as little as +3 weeks on a tank and you live in a moist area... You'll have issues with E85 with the stock tank.

Few of us have ran E85 with good results however it also has its negatives. Main problem i've had with it has been moisture. E85 partially turns into acid when it collects water and that acid doesnt like to burn.

2 fuels/pumps sounds stupid.

From talking to people who run E85 here's how it works.
- You have 2 maps - end of story. One for E85, one for pump gas of choice. The timing is so different for E85/pump gas that you can't simply have the ECU add a few degrees depending on fuel composition
- Switching from E85 to gas is easy, just run your tank to near-empty, put the other fuel in, change maps, and drive normally for a bit.
- Fuel composition sensor is nice, BUT only as a safeguard against different E85 mixtures . Sometimes E85 will be more like E70 and a flex fuel sensor will allow you to to avoid re-tuning fuel. Using a fuel sensor for gas AND E85 is a bandaid approach. See first point.
- If your gas station is 30 minutes away, get a 55 gallon drum, fill it up and store it at home. Storing it is doable if you take precautions against moisture


Hope that answers your questions.

I down a tank a week now na. Turbo and e85... My lead foot would need two a week.

Going to check how close the closest e85 station is to my work. I might just see if it is possible to fill up after work when I need to.
A little more wor and hassle, but everything about a turbo car is a little more work.

So just buy two-three 5-gallon jugs? you need them if you intend to track your car anyways - which is not clear from your first post, btw.

Car is mostly a daily. I drift at events 6-7 times a year. And there is e85 near the track ( heartland park topeka )
The.spare jugs of gas would be good to have too.

If I get a hitch and trailer I might attend more events. Would be fun to do some road courses, but not really into the scca style grip events.
I've always liked going sideways. Grew up on gravel. I liked "rally driving" before I liked drifting.