Flex Fuel in HPTuners=DONE
 

I have managed to get flex fuel working in HPTuners. I know a lot of guys have been waiting for this, or told it was impossible to do ect. so I finally got around to trying to get it going. There really isn't some magical thing needed, no special programing, no secrete password ect.. It really is very basic, and for the most part follows every other flex fuel enabling protocol. I'm not sure if tables/inputs/ect were missing before, or if no one really tried that hard, but here it is. I have a small video clip in my build thread showing it working for the inevitable doubters. I have thought long and hard about this, and decided I don't want the burden of people possibly blowing up their engines, due to the complexity of tuning flex fuel "correctly", so Im going to show the basic settings required for an experienced tuner to make the necessary changes. If you are going to be tuning for flex fuel, you will already know what else is needed from here in order to get a functioning sensor communicating. The stock tune needs A LOT of adjusting. That is a massive understatement at best. DO NOT attempt to use your stock file.

Yay, been waiting for a smart person to try this.

Interesting.. awaiting more feedback..
Does this by chance have anything to do with yours being an '18 model or will work for all '16-'18s. Was there a HPtuner update we missed?

When you say we who are you referring to?

How are you wiring the sensor into the ECM?

And yes Cooper1965 is correct, many many tables to adjust to get a strong and safe combo. You can expect and easy 30-50HP more when on corn fuel and properly tuned.

When I switched mine over I went from lo 13's to mid 12's!

It should not matter on the year, if anything the 18' is the most difficult because GM can't leave anything alone. I got curious on the HPT update's your brought up, so this morning I have been rolling through the previous versions of HPT, so far, the past 4 updates have everything needed to get flex up and moving.



I used service terminal 7116-4152-02, it is in Yazaki tray 9, to connect to the PCM. (That "could" be different depending on year, I did not check)

Todays MVP of the internet goes to.....(Insert painfully long drum roll/zzwho cam chop here) Cooper!! I already have flex available because I have (looks around for forum police) an ATS but I understand this is huge for you guys. Hope to see more progress soon.

zzwho hasnt looked at this in over 6 months....judging by this post, HPT finally actually connected the back end of the sensor function with the latest update? previously, you could turn it on all you want, and it would just report 46% ALL the time. if this is actually fully fuctioning, and reporting properly that is BAD ASS! good find coop!

I believe it is reporting properly. I had "mostly" straight 93 octane fuel in the tank to start testing (for obvious reasons), OFC that is roughly 10% ethanol. FCSU (fuel comp frequency) HTZ was at 63 showing 12ish% ethanol in the log.
Added a few gallons of E85 and and FCSU HTZ jumped to 71ish and logged ethanol jumped to 21ish%. There were some other changes too according to my tune (timing, ect.ect.). Unless Im completely overlooking something major, its working.

Dont be sleeping on Coop. Hes been making a bunch of progress on his own doing a bunch of research and tweaks. Hopefully soon it can be implemented across both platforms and get all of the LTGs hooked on corn.

How many is a 'few' gallons?? It didn't change much if you added a few gallons. I got this mixing down to an art now. Pretty sure you got the same size tank we do so when its on empty, 6gal of e85 and 8gallon of 93 gets me 40-42% ethanol everytime. Thats what i have to run in the winter to keep the fuel system in line and not commanding super high duty cycle. Which contrary to some on here, makes them run lean (while showing ok on the wideband)

19 Gal tank, started with a full topped off tank of 93 attempting to water down the last little bit of E in the tank, so that was roughly 12% E. Drove around and logged, made tune changes, logged more, more tune changes ect. Burned maybe 2.5 Gal of that fuel and decided I was happy with the function of the sensor. I then topped off again with a 'few' Gal of E, leaving me at roughly 21% E.

You've made my day:thanks::thanks::thanks::thanks:

Cool, nice and steady progress.

FYI, little inside tip if you didnt already know. You will need to raise your virtual torque tables for e85 as the stock ones are way to low. With the power you'll be making it helps to raise them 5-10%. It fixed a few drivability issues i was having in 50-70% throttle settings.

Also there are some sneaky torque tables and timing tables that are harder to find that will need adjusting. Lucky you as you get to convert axle TQ to engine TQ in your setup.

Keep an eye on your HPFP and inj duty cycle%

Have fun!