Switching to E85 - Timing Advice?

[06300CSRT8]

I don't have much experience tuning e85 setups. The fueling side changes seem pretty basic and I plan to change the following:

Target Stoich values
Power Enrichment Aircharge and PRatio tables
Startup Inj PW (Startup Base) (multiply this by about 1.25)

But I am curious what to do with idle, part throttle, and wot timing. WOT timing I'm inclined to leave alone and add as I move along, but in general how does E85 like to run off WOT? I know from tuning pump gas setups with larger cams the idle timing becomes very touchy, less can be better is the norm, but I don't want to not run enough.

[06300CSRT8]

Bumping this up, would love to do a better search but "e85" is too short and "e85 tuning" returned nothing.

[Seanfarley25]

What timing are you seeing at wot? I would add a few degrees across the board in the partial throttle areas to improve fuel economy. Even though you are going to get roughly 30 percent less fuel economy from the switch to corn. And a few degrees for the wot table also. You are most likely not going to see any knock as e85 is around 105-108 octane on average.

[Blue Bee]

https://tapped-performance.myshopify...-flex-fuel-kit

This, then you only have to worry about timing. Let it control fuel.

[06300CSRT8]

Not much info on that actual website on how the system works, I assume after taking the reading with the sensor it then sends a modified signal through the 02 sensors? My 2014 doesn't have widebands from the factory, not sure if that matters. How does it actually work?

[06300CSRT8]

Nevermind, I see now that it actually splices into the injectors and provides additional dutycycle to the injectors based on the ethanol content. Pretty crafty.

[06300CSRT8]

Not a fan of no active monitoring of actual fuel trims or stoich, esp under WOT. Its a open loop/SD controller that has a straight line enrichment code based on the ethanol sensor. They should add an additional layer to the controller that incorporates a wideband and additional dutycyle based on the wideband output.

[06300CSRT8]

pretty sweet, dumped the tank last night, filled up on x85. Changed stoich values, adjusted my PE table adders, fired right up and ran perfect. Fueling only off about 4-5%. Left timing alone, seems to idle and drive just fine.

Still have this damn hard hot start issue, its identical to when on 93 octane.

[Blue Bee]

The Flex fuel kit works perfect, why would you need a wide band? If your tune is dead on, it will be dead on no matter the alcohol %. It only looks at what PCM is commanding, modifies PW based on alcohol. No need for it to look at a wide band. We know what amount more is needed for stoich of a certain %, it's just added in based on PCM PW commands and what the sensor is telling it for content %.

[06300CSRT8]

It?s the same concept of why dodge and ford incorporated widebands to the factory fuel monitoring, you think the thousands and thousands of cars produced by those manufacturers aren?t ?dead on? yet they still make use of a wideband for flex fueling and monitoring?? Just seems lazy, the flex fuel sensor has an output in the same voltage range as a wideband, why not base it on the wideband? True flex fuel systems use fuel trims for flex fuel adjustments, same concept you?re arguing, they assume the tune is dead on and if fuel trims start exceeding a certain amount it assumes the delta is alcohol being introduced. Either way, basing fuel adjustments on actual observed fueling is much safer and logical than mathematical tuning based on alcohol content. Just my humble opinion. This device isn?t for me, def not for my setup.

[Blue Bee]

The wide band way and watching trims is lazy, I prefer to change fueling before the burn instead of after...as in having a wide band change fueling after combustion has happened. With this setup the transition happens before the O2 even knows it, it's smoother, safer. I've had GM cars in which I added sensor and set up flex in the tune make more power just doing the controller kit because it has more resolution and reacts faster. Why not have this get fueling super close then yes, have the O2's correct smaller amounts like usual, that's my opinion. Using these kits on 1,000+ HP setups, plus if you need you can fill up on pump and drive away without changing tunes and going through the brutal transition process. I'd rather have the O2 correcting 1-4% than 20+% each time the throttle is stabbed. (shoulder shrug)

Also Ethanol sensor is not the same voltage output as wide band, it's actually fed voltage from PCM and is a frequency output, I use this kit, 1000cc injectors and spray 200hp shot on my stock 6.4.

[06300CSRT8]

I see where you are coming from, but sorry I have seen "calculated" tune adjustments not be in tolerance to the closed loop fuel trims. Case and point is my own tune, i just did a full log. I started the e85 tune with a calculated fuel adjustment based on the new stoich value of the fuel I used and fueling was off 20+% in some of the higher pressure ratios. My 93 tune was DEAD nuts, commanded vs actual lambda was less than 1% off and fuel trims no higher than 2-3%. All I am saying is there are variables that will make a precalculated duty cycle change be still off too far. I would bet on if I had used your device on top of my 93 tune, it would also have been 20% off and I still need a tune change. Would be nice to have a device like yours that does both a duty cycle adjustment AND monitors lambda via a wideband during open loop to really make it dead nuts. No one pre-2015 has open loop fuel corrections in the gen3 hemi world, would be good to have a controller that does so. My tune would be a popped piston in short order without some further tweaking.

As an aside i know why mine is so far off, because I am running VP X85 which has a higher oxygen content than standard ethanol fuels. Just one of the variables that would need a footnote in your instructions it wouldn't work for.

[Blue Bee]

Mmmmm, no. Not once has this been off more than 5% from a pump gas tune that was 3-4%. For it to be 20% as you say would mean the kit wouldn't even be working. There are more of these kits on 14 and older than 15 and newer. My 16 Scat doesn't have wide bands or do open loop corrections....? I installed kit, filled with E and didn't touch my tune for 7 months until I installed 1000cc injectors and my LTFT were less than 3%. If the controller looks at Ethanol and adjusts the majority then the PCM is still only doing normal trims within a couple percent, and if your tune is far enough off to pop a piston even 10% off, you had other problems. To think this wouldn't work and would blow an engine is laughable considering the number of guys out there with "dedicated" E tunes getting pump and may have been tuned on E55 then next tank is E75 and way lean and they don't even know it.

[Homer]

Hey Blue Bee, any concerns running liquid corn through the stock fuel system? From what I have seen when installing a larger fuel pump when I went FI, I don't see it being a problem but according to the naysayers, running elevated ethanol blends on a non-FFV fuel system is no bueno.

[Blue Bee]

Hey Blue Bee, any concerns running liquid corn through the stock fuel system? From what I have seen when installing a larger fuel pump when I went FI, I don't see it being a problem but according to the naysayers, running elevated ethanol blends on a non-FFV fuel system is no bueno.

Lots of myths about that floating the net, just ask some of the FB forums! Haha, but no, my car has been running E for quite some time, I have 40K on it and only switched to 1000cc injectors recently as the stockers just couldn't flow enough for my power levels. Ethanol only destroys natural rubber, as manufactures knew ethanol was going to be a part of automotive fuels since what...1985ish...these kits are on vehicles as old as mid 90's with 100k+ miles on just E and no issues. Like I said, this system is not new, just new to the Dodge platforms.

[efficace]

Hello
I am looking for information to make a 2008 Dodge challenger SRT V8 6.1L compatible with E85
Is it necessary to add a sensor?
Is it necessary to change the injectors?
What parameters should be modified?
Can someone provide me with a file to analyze the changes to be made?
I am a beginner, it would be very nice if someone could help me

Thanks in advance