Advice on creating an E85 FI Tune with Openflash
 

Hello friends,

Ive been running the SBD Turbo for a little over a month now using Shivs OTS tune for it on 93 pump gas. I'm currently running only 7psi, since I've been trying to learn as much as possible before going up in power, with the hopes of doing it safely. I've been making slight tweaks and logging every single drive I've taken for the past three weeks, which is helping my learn a lot, but I still don't feel ready to make a change as big as jumping to E85.

With that being said, I'm not asking for others to do the heavy lifting here. I was just hoping that some of you very knowledgeable guys on here could help guide me in the very general outline of how I would go about making my own E85 tune.

Really any advice would be appreciated, especially things like peer reviewed papers or books that I should read.
:thanks:

https://www.hpacademy.com/blog/how-m...u-make-on-e85/

Should start pointing you in the right direction.
You have fuel system upgrades?

Don't forget the power of comparing Roms. (For example, the ESC 91 and the ESC e85)

I'll get to reading that tonight, thank you!

As of yet I have no fuel system upgrades. From the reading I've done it seems 280-300whp is about the limit of the stock fuel system, but I believe that was pump gas. Using a (very) rough 30% volume increase for E85 I'd guess 240-250whp would be pushing it on the stock system, so injectors and fuel pump will for sure be in the car before attempting to go above that power. You have a very excellent point in that comparing two FI tunes that run 93/E85 is a great place to start, I just wasn't sure I'd be able to get my hands on them. I'll start tearing apart those ESC tunes to see the differences.

Have a look at the differences between Shiv's gas and E85 NA tunes. You'll need to add somewhere around 30% extra fuelling via port injectors (Divide Injector Flow Scaling BRZ by 1.3 in Romraider) and also via DI system (Multiply GDI Pressure Multipliers A and B by 1.3) then fine tune your DI:PI balance.

You'll also need to try to understand where your DI and PI fuelling maxes out and adjust DI:PI ratio so that you have some DI and PI headroom at the top end.

Timing changes after making your fuelling safe.

Also have a look at your MAF voltages: you may be close to maxing the MAF and consider working on speed density high up in the range.

I haven't gone to E85 due to lack of local supply.

Feedback like this is exactly what I was looking for, can't thank you enough.

PM me if you want a copy of my latest ROM (Greddy T518Z). Still a work in progress, there will be some differences but should be quite similar to an SBD unit.

I've also done calculations for where I'd kick PI in for E85. I'm running DW450's, would probably get a bigger fuel pump if I were to switch to E85 due to my calculations.

I've also coded a hybrid speed density solution that looks quite promising but I will do more testing before sharing.

That's awesome. Looking forward to it!

PM'd :thanks:

Bigger fuel pump and injectors I figure are a given, since by some rough interpolation of the ~300whp stock fuel limit, volumetrically the E85 stock fuel limit would probably be near 220-240whp.

Im a little confused on what you mean by hybrid speed density solution. My best guess is that fuel (or air?) density changes based on the respective speed that the fuel or air is being pushed in, so you have to account for that. What exactly do you manipulate to take that into account?

Feel free to be as detailed as necessary, I'm actually a software engineer but my degree is in Aero, so don't be afraid to throw anything difficult at me. I'm here to learn and you guys know a lot, so this is great.

Speed density estimates mass air flow based on rpm and air pressure, accounting for intake temperature and volumetric efficiency of an engine at a given rpm/pressure. My hybrid solution allows full MAF operation up to a certain threshold, then progressively blends in SD calculated mass airflow up to a second threshold above which pure SD operation is used.

Lots of good information on NASIOC and RomRaider forums. If you're a software engineer (I'm not), I'd be happy to work with you collaboratively. I've used IDA to try to understand the ROM and HEW to verify my ROM coding.

I'd be more than happy to collaborate on something. What kind of program do you think would be useful? Most of the work I do is analyzing or trending parameters to determine performance characteristics of certain jet engines. If you can think of a way to leverage my skills I'd love to contribute to the community. Ive started looking through the romraider forums and there seems to be a ton of great information there too.

So if I'm understanding it correctly your hybrid solution essentially fills in where the MAF sensor is no longer accurate /out of range. Interesting..

That sounds pretty promising. I'd love to see where it goes. I'm still fine tuning the edited it's SBD ROM for my full blown kit. (2 days after install I took a 1700 mile road trip. So far so good. Still need to upgrade fueling so I can run an e85 map.

know nothing about speed density tuning or coding but mad-sb did a bit of a how to for e85 on an NA car here

http://www.ft86club.com/forums/showthread.php?t=39375

their is also a guy developing a opensource flex fuel sensor but would need coding in ecu to intergrate to opensource tunes.

http://www.ft86club.com/forums/showthread.php?t=79865

First off I'd just like to say that I've read a ton of your posts and guides, you're the man.

I read the thread with the guy making the open source %E sensor, I believe he's sent a few units out for beta testing but that seems extremely promising. The first link you posted I haven't gotten a chance to read through, but I'll do that once I'm done packing tonight.

Hopefully between all the minds here we can help make a pretty solid E85 tune for us FI folks.

Ztan has sent me a bunch of the work he's done so far so hopefully I'll get a lot of time this week to really dig into it.

On that note, I'm about to pull the trigger on the Deatschwerks 65C fuel pump and some 1000CC injectors, since I won't get much of anywhere without the right fueling support.

Edit: Second guessing the 1000CC injectors, my car is daily driven so I may go for a more manageable 700cc and stick around 300whp max.

Interesting Thread. Any updates in your E85 pursuit?