Theres these things in the ECU called Fuel Trims... Going from E85 to E60 wont matter if you E85 trims were good. Cruising around and idle will set the LTFT and STFT to adjust and then full throttle is Open loop so it should naturally be compensated for. But in general, E85 doesnt really care too much about being lean or rich too much. ER has done tests with running 12:1 thru 10:1 and neither direction made significant power differences.

Timing and boost is where the magic happens.

 

Agree with you on the by the pump conversations..Lol...Yeah back when I first started running it 100 oct was $8 a gal. Made more power with E-85 too. Was a total win.....win. Blame it on razor.....he got me hooked on it in my RS and now in my Fiesta ST.

 

Doh yea dunno why I said lean. But yea, there's no issues being 10-15% off in mix.

And yea you can (have to) run more timing on ethanol because it burns slower than gas but yes you can make a good chunk more mid range torque on ethanol just with timing adjustments.

 

Pretty much everyone turns off Fuel Trims affecting WOT operation in tunes so no, WOT fueling will not compensate based on closed loop LTFT/STFT adjustments. That said, if you don't have a kill tune for E80 then E80 --> E60 is just fine, you'll run richer because of the higher gasoline content and all will be fine. If your E80 tune is kill mode, then yea, you could melt / blow some things up.

I really wish mitsubishi had closed loop fueling operation in their ecu. My Fiesta was so easy to tune on Ethanol mixes because I never had to touch the fueling tables. It just used the wideband and hit my targets with compensation every single time. My VW is the same. Of course, they make up for the ease of that with 5,000 timing tables that are a total pain in the *** to tune.

Even the new BRZ/86 twins from 2017+ have closed loop WOT operation. Get with the program Mitsubishi, pun intended.

Now that I live in New Jersey, I finally get 93 octane but there are only three E85 stations in the whole damn state so... yea that sucks. I don't even bother running mixes on my daily drivers now. Just run 93. Plus mixing tanks is a bit hard when you can't pump your own gas..

 

You guys just need to hop on the aftermarket ecu train.... Then there is nothing to worry about. ECU takes full control of everything based on ethanol content %. Plus a full time functioning wideband even in boost..... Its all a win.

 

Yea considering the stock ecu is over 15 years old I'd say it's fairly sophisticated. Compared to today's standards, hell no, but that shouldn't be a surprise. I've been eyeballing standalones more and more. At some point in the distant future I'll make a custom chassis and engine harness for my car after I decide what standalone will be thrown at it...

 

I wish... But California. As soon as Cali changes it's laws or I retire the evo from DD I'll be all over an aftermarket ecu.

 

You let me know when you get that figured out. Maybe we can make a trade for some billet goodies!

 

So keep your stock ECU for smog time. Its not that hard or time consuming of a swap. I can have my car running on the factory ecu in 5 min.

 

Hmm, guess I didn't know that was turned off. I'll have to look into it to see if that's just standard setting on Tephra V7 since I did all the mods to my ECU. In my DSMlink days IIRC it was always fine especially since we were in the early days of E85 and there was probably more variability in what we got. But I guess I could be wrong there too. Ive always just dialed in LTFTs and checked occasionally and my AFRs never really shifted around.

This winter Im bailing on Stock Ecu in general. Seems which direction to go depends mostly on who's doing the primary setup and dialing things in and what they prefer. Since ER is my guys, they prefer AEM infinity so thats the direction I'll go. #1 reason Im switching is logging capability. OEM ECU sucks so bad for logging. Data rate and ability to quickly view the data are terrible. #2 Reason to switch, safeties. It isn't till #3 that I care about getting modern tuning capabilities like WOT closed loop or a proper VE table for speed density.

 

If my area had 93oct then yeah...different conversation. I have all these yahoos in my area posting all over Facebook how cheap it is to run on e85 because it's so cheap to fill. Apparently they never look at their trip meter. : lol:

 

It's been a long time since I've really looked into stand alones, and what they bring to the table vs. a tuned stock ECU. There have been many challenging aspects of working with the stock ecu, but in general I have had a lot of fun figuring them out and making it work. After 10 years of turning the knobs I'd like to think I have a good handle on the stock ECU, moving to a stand alone would almost be starting from scratch again. Which I'm totally open to if the benefits are there. For example I don't need flexfuel because I only run E85, but some other features, like closed loop WOT or Drive by wire are very tempting. Obviously you can't just swap a Drive by wire setup quickly though.

 

I have run into these folks at the pumps too. Talking about how much they are saving running E85 in their BRZ or what ever. I don't want to be the one to break it to them so I just let it go.

 

It's not the rom it's just how many pro folks tune the cars due to not being able to spend as much time with the car as the earlier folks who were tuning their own cars.

 

AEM and Haltech used to be good. I tuned quite a few of them 2005-2012, 2jz-gte, sr20det, RB2X mostly.

Now they are even better. The outputs for nitrous, closed loop boost control, flex-tuning strategy (boost vs flex content), methanol/water injection control, staged fuel pump activation, oil and fuel pressure logging inputs among other things... are all welcome additions to 'true' performance control.

You can do many of these things without the Stand-alone, it's just tricky. Closed loop boost control just like anything else can be done using Arduino and Coded in C. It needs to be tested and engineered correctly though because wrong signal to solenoid can blow the engine, seen it happen.
Warning for fuel pressure and safety cut-off for fuel and oil pressure plug logging can also be done through micro-controller or simple transistor circuit.
Pump activation... nitrous.. for many years we did these things without the fancy Stand-alone computers.

But now that you can get it all in a nice plug and play package for reasonable cost... seems silly not to use all that power packaged together. Little bells and whistles... theres a panel to turn off the alternator at WOT, control charge duty. Injector phasing and end of injection (not all OEM ecu let you adjust this from ~02 up), completely adjustable rev-limiter (cut each cyl sequentially to spread out fuel-cut behavior) its go so many adjustments you will probably forget one of them and wonder why the engine acts funny sometimes.