Flex fuel conversion (everything you need to know)

[JRoyPDX]

Subcribing. Successfully done on 2017 trucks, yes?

[JRoyPDX]

Can you have GM load the factory e85 capable tune file with fuel tables and be fine or does it have to be hp tuners or other capable aftermarket tuning software?

Per a gm tech on another board, ecu calibration for flex fuel is not on the list of approved dealer upgrades so they won't do it. That same gm tech says he can and has done it.

 

Moral of the story, make friends with a good gm technician.

[Black02Silverado]

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[Cowpie]

Where e85 really came into its own is back when we had $4 E10 gas several years ago. E85 was $1 - $1.50 a gallon less in my area. My 2013 lived on E85 for a full year. Haven't used it much in the last couple of years, but have used E15 frequently. It has typically been about 10 cents cheaper than E10 and delivers almost identical fuel economy.

[sdeeter19555]

Doesn't it require different injectors? I thought it was more than just programming?

 

Sent from my SAMSUNG-SM-G900A using Tapatalk

[Cowpie]

I would say, no. Simply because GM traditionally uses the very same components in flex fuel engines as they do their standard ones. I hauled production parts to both Ford and GM assembly plants for years. They like to streamline inventory, so they typically use the very same components in a vehicle and engine combination. Only the ECM is the issue, with maybe the need for the ethanol level sensor to let the ECM know what the ethanol percentage is.

 

Different jets were needed for carbureted vehicles in the past. With modern fuel injectors, not so much. The amount of fuel delivered, and timing of the event, is controlled by the ECM. And the ECM would compensate for the fuel being used. And based on the substantially higher octane level of E85, and it's cooling effect on the combustion chamber, the event could start sooner without the risk of pre-detonation.

[kivetts04dmax]

Just thought this was an interesting topic because I was toying with the idea of running E85..if our vehicle is tuned by black bear, would they be able to make the correct adjustments to the ecm or would you have to send them a file?

[kivetts04dmax]

bump, really wanting to buy kit if compatable with other tuning unless using e85 is dead now?

[Black02Silverado]

On 2/8/2018 at 12:04 PM, kivetts04dmax said:

Just thought this was an interesting topic because I was toying with the idea of running E85..if our vehicle is tuned by black bear, would they be able to make the correct adjustments to the ecm or would you have to send them a file?

If you vehicle is set up for FF then yes, Black Bear can tune it and you will see a difference once they do.  Most are getting anywhere from 10 to 18 more rwhp when tuned for FF.  Not to mention the capability to run a high octane fuel that burns cleaner and is less cost at the pump. Depending on the spread of cost between FF and regular it might not be less cost in that reguard.  Like for me, FF is $2.02 a gallon and Premium is $2.89 so for me to run FF it is less expensive per mile then to run premium.  You just have to do the calculations to see if it is for you in your area of the country.

[Josh154]

Wow. I can get pure 85% e85 here for $1.29 a gallon and 93 costs me 3.40 a gallon. My 6.2 is not flex from the factory, id like to add the sensor but black bear and diablew won’t touch e85 if the truck didn’t come flex from the factory. 

[Cowpie]

Yeah, the NW Iowa, SE SD area has the cheapest E85 around.  I filled with E85  a couple of weeks back in NW Iowa and it was about $1.49.   In my central Iowa home turf, it is about $1.69 for me.  Doesn't matter if we are talking regular or premium, or even the good mpg of a diesel.  Using E85 currently gives me the lowest cost per mile.  This situation now, as well as the one a few years ago when we had fuel prices in the stratosphere, has solidly sold me on always having flex fuel engines.

[GhostWriter]

1 hour ago, Josh154 said:

Wow. I can get pure 85% e85 here for $1.29 a gallon and 93 costs me 3.40 a gallon. My 6.2 is not flex from the factory, id like to add the sensor but black bear and diablew won’t touch e85 if the truck didn’t come flex from the factory. 

Those of us with a long view recall the long list of (supposedly) modified components that were necessary before a vehicle could be badged Flex Fuel.

 

Eventually, some of these parts may have become standard; however, if there's no evidence that a particular model year or engine code allowed for Flex Fuel operation, then the programmers have probably made a wise decision.

 

The other thing that's interesting is the mention of the sensor.  There's no ethanol (alcohol) sensor on my Flex Fuel.  By 2008, the engines were adjusted for ethanol content using the O2 sensors. and modified programming. 

 

If GM reversed course and began installing ethanol sensors, again, wasn't aware of it.

 

 

[kivetts04dmax]

7 hours ago, Black02Silverado said:

If you vehicle is set up for FF then yes, Black Bear can tune it and you will see a difference once they do.  Most are getting anywhere from 10 to 18 more rwhp when tuned for FF.  Not to mention the capability to run a high octane fuel that burns cleaner and is less cost at the pump. Depending on the spread of cost between FF and regular it might not be less cost in that reguard.  Like for me, FF is $2.02 a gallon and Premium is $2.89 so for me to run FF it is less expensive per mile then to run premium.  You just have to do the calculations to see if it is for you in your area of the country.

thank you, I’ve read a lot on e85 and the results..my main question was since I have tuning by Black Bear already and didn’t want to pay for a new tune, if they could just adjust it for me. Since they will be able to, I’m going to go ahead and get the kit. I’d like the option to run e85 since I’m from the Midwest and I know it will be readily available there..

[kivetts04dmax]

6 hours ago, Josh154 said:

Wow. I can get pure 85% e85 here for $1.29 a gallon and 93 costs me 3.40 a gallon. My 6.2 is not flex from the factory, id like to add the sensor but black bear and diablew won’t touch e85 if the truck didn’t come flex from the factory. 

If you got the sensor installed before they tuned it how would they know? When they go in to adjust the parameters wouldn’t they see that the sensor is there and reading? 

[Josh154]

A local shop told me they could install the sensor and tune it for e85. No 6.2 comes from gm flex fuel ready. 

 

I was just at that shop the other day, he said they’ve tuned multiple 6.2s on e85. All the e85 tables and everything are there on the factory map, just need the sensor.