Tuning for e85

[dbb2797]

Hey everybody, I'm going to be converting over to e85 for my 11 Mustang GT. I think I understand all the steps needed but wanted to clarify. I will also be installing the FRPP 47# injectors. The car is NA so no power adders. I do have LT Headers, Cobra Jet IM, Cobrat Jet Mono TB.

These are my plans:
Change stoich to 9.86
Copy the injector data from the stock Roush TVS tune (should be the same injectors?)
I will drain the gas out and replace with E85.

To dial in spark, I normally run about 26 at WOT. with all advance and retard 0'd out So I will start at 28 at WOT and enable advance and retard. After datalogging I will see what spark advance the ECU goes to and then set that for spark and datalog again.
Clean up any MAF data if it's off.

Anything else I might be missing on this?

Thanks!

[murfie]

You will probably get to the MBT values for gasoline and that will limit you. The new MBT values for E85 are higher as it is a slower burning fuel and cylinder pressure doesnt increase as fast. How much higher depends on RPM and load for how full the cylinder is getting. If you have a dyno you can increase spark until you get knock or until you don't make more torque. On the street you may actually get above the true MBT spark value causing less power and unnecessary pressure fluctuations in your cylinders. where you see 26 at wot you should be around 32-33*.

[dbb2797]

You will probably get to the MBT values for gasoline and that will limit you. The new MBT values for E85 are higher as it is a slower burning fuel and cylinder pressure doesnt increase as fast. How much higher depends on RPM and load for how full the cylinder is getting. If you have a dyno you can increase spark until you get knock or until you don't make more torque. On the street you may actually get above the true MBT spark value causing less power and unnecessary pressure fluctuations in your cylinders. where you see 26 at wot you should be around 32-33*.

Thanks for the awesome info murfie. I will do my WOT datalogging at the track and use weather data and 1/4 mile times to determine if I'm making more power. I'll start out with MBT at 32 as well.

[Plimmer]

You might want to also try different lambda values. I haven't dyno'd different values, but seat of the pants I found a leaner lambda worked better with e85. My 0.82 for gas seemed to work better with 0.85 for e85. But like I said this was seat of pants, not dyno tested.

[Dev1360]

FWIW, on E85 with my CJ, this was the difference in .82 and .85 lambda. Same stretch of road, only change is the fueling. I didn't FEEL that much difference, but the log data, and the VD data both support some gain.

VD.jpg

[dbb2797]

That's great info about running it a bit more lean guys. I actually run at .84 lambda on 93 and my 1/4 mile times show that running a little bit leaner even on gas gives me more power. So I will try running at .85 on e85.

[txcharlie]

You should dial in your MAF on gas before switching to E85. It will make things easier. As for stoich value, buy a tester kit and set your stoich to your test result. Chances are, you won't have to touch the MAF.

[dbb2797]

Hey everybody, I've done my e85 conversion and am seeing an issue.

I installed the 47# injectors, tested on gas and after figuring out a vacuum leak, everything looked good. The car idled great with lambda right at 1.0
Next I updated the tune changing stoich to 9.86. Ran a tune to run the fuel pump and drained all the gas out. Then put in 5 gallons of E85 which was tested to be 85.

I was able to start the car and idles, but it's idling very rich. At about .83 lambda. I'm getting a Fuel Source in my data log for (OL) FMEM. Does anybody have any ideas what this is?

I don't have my tablet in front of me to post up the tune, but it's identical to this one with the exception of the change for stoich AFR to 9.86 being the only difference.
https://www.hptuners.com/forum/showt...-frp47-install

Any thoughts?
Thanks!

[15PSI]

Hey everybody, I've done my e85 conversion and am seeing an issue.

I installed the 47# injectors, tested on gas and after figuring out a vacuum leak, everything looked good. The car idled great with lambda right at 1.0
Next I updated the tune changing stoich to 9.86. Ran a tune to run the fuel pump and drained all the gas out. Then put in 5 gallons of E85 which was tested to be 85.

I was able to start the car and idles, but it's idling very rich. At about .83 lambda. I'm getting a Fuel Source in my data log for (OL) FMEM. Does anybody have any ideas what this is?

I don't have my tablet in front of me to post up the tune, but it's identical to this one with the exception of the change for stoich AFR to 9.86 being the only difference.
https://www.hptuners.com/forum/showt...-frp47-install

Any thoughts?
Thanks!

Normally you will receive this error if a sensor has failed or out of calibration.

From the web:

Failure mode effects management (FMEM) is an alternate system strategy in the powertrain control module (PCM) designed to maintain vehicle operation if one or more sensor inputs fail. When a sensor input is perceived to be out-of-limits by the PCM, an alternative strategy is initiated. The PCM substitutes a fixed value and continues to monitor the incorrect sensor input. If the suspect sensor operates within limits, the PCM returns to the normal engine running strategy.

[tbrtuning]

That's great info about running it a bit more lean guys. I actually run at .84 lambda on 93 and my 1/4 mile times show that running a little bit leaner even on gas gives me more power. So I will try running at .85 on e85.

Track Key tune shows Ford running the Boss at like 0.86 when using the track key.

[Jn2]

Track Key tune shows Ford running the Boss at like 0.86 when using the track key.

yup they run it lean and run more timing, stock I honestly think that set up would prob run into some KR on 93 octane...

[Blueprint]

Sounds a lot like my issue!!! Mine will idle in the same area. If I can keep it within a certain area it will not go into FMEM.

However once it gets too rich, it will go into FMEM. I assume because it thinks something has failed.


There are actually a few people experiencing this issue. Im pretty sure this is a HPtuner issue.

Think about it all that you changed was the stoich value and fuel.

Someone else also changed injectors and experienced same issue. I'm using a tune that works on many different cars and actually this same engine just in a different car, flashed to new car. Now I have this issue. Tried everything new sensors, new MAF, new harness, new strategy, hardware checks, some extremely experienced tuners have gone over tune, with no obvious issues.

[dbb2797]

It appears I got past the FMEM issue. I set stoich AFR min to 8.85, reflashed the tune and now the FMEM limit is gone. Before I reflashed I checked the code I was getting and it was p2196 aned p2198 sensor signal stuck rich. Even though the label is that the stoich AFR min is used only for flex fuel, it appears to have made an impact. fyi I also don't see the flex fuel logic so maybe my strategy doesn't have it available.

I will be doing more tuning at the track tomorrow too for spark. My MAF looks to be pretty spot on at the moment too.