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Flex Fuel Conversion

Stonehenge

By Stonehenge
in Engines & Drivetrain

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JONBLARC7 Enthusiast

JONBLARC7

Posted
Posted (edited)

No it doesn't move it that much.  It's raining today so I'll craw under there tomorrow and snap some pics.

Edited by JONBLARC7
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SinisterZ71
SinisterZ71

I've got a 2018 Silverado K1500 extended cab short bed that did NOT come with the flex fuel option.   I ordered a Continental brand flex fuel sensor p/n: 13577429 and Flex Fuel Sensor Rear l

CamGTP
CamGTP

Yes, the sensor and a tune will allow you to run E85.   Once everything in the computer is enabled it will work as if it came that way from the factory.   I'm currently running som

Mike GMC
Mike GMC

Besides the fuel sensor, what comes in the "kit"?  Why not just buy GM OEM parts?  They seem to work pretty well.

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JONBLARC7 Enthusiast

JONBLARC7

Posted
Posted

The red circle is the clip you pull the flexible fuel line out of.  The green is the stock connector re soldered in it's new location.  I just went to Lowes and bought a (4 in 1) 22 gauge wire and only used 3 of the 4 wires.

 

IMG_0711.jpg

Nitrousbird Enthusiast

Nitrousbird

Posted
Posted
5 hours ago, JONBLARC7 said:

couple more showing how far it is from the drive shaft

Was it not an option to simply buy the factory GM lines for Flex Fuel and put the sensor in the OEM spot (well, OEM spot for a 5.3L FF truck, I get that GM never offered it on the L86).  I'm not understanding the need to relocate the sensor to another location.  

JONBLARC7 Enthusiast

JONBLARC7

Posted
Posted

Yes you could do that but then you have to replace all the fuel lines from the fuel rail to the gas tank because nothing matches up.  This literally took me maybe 20 mins to add to the truck.  And that includes me have to crawl out form under the truck to clean off.

 

Because I forgot the Fuel line was still full of fuel when I decided to unhook it while I was laying under it :banghead:  :lol:

Stonehenge Enthusiast

Stonehenge

Posted
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Posted

After I install the sensors/kit I am getting mixed messages.  BlackBear will turn on the ability to run E85 via a tune update.  Is this all that is needed to reap benefits from e85?  I want flex ability to swap between e85 and 93 pump without having to reflash a tune each time.  With this in mind what BlackBear is suggesting makes sense.  They offer a 91+ tune and turn on ability to run flex after the sensor is installed.  They are saying that the 91+ tune with flex option turned on is all that is needed to run E-85.  But will I see performance benefits this method or does this simply give me an option of running alternative fuel type?  I am getting  mixed messages, others are saying I need a tune specific for E85 to reap performance benefits.  

 

I reached out to BlackBear and waiting to hear back but was curious if anyone has done flex conversations with BlackBear tune and can chime in on experience.

Black02Silverado Senior Enthusiast

Black02Silverado

Posted
Posted
20 minutes ago, Stonehenge said:

After I install the sensors/kit I am getting mixed messages.  BlackBear will turn on the ability to run E85 via a tune update.  Is this all that is needed to reap benefits from e85?  I want flex ability to swap between e85 and 93 pump without having to reflash a tune each time.  With this in mind what BlackBear is suggesting makes sense.  They offer a 91+ tune and turn on ability to run flex after the sensor is installed.  They are saying that the 91+ tune with flex option turned on is all that is needed to run E-85.  But will I see performance benefits this method or does this simply give me an option of running alternative fuel type?  I am getting  mixed messages, others are saying I need a tune specific for E85 to reap performance benefits.  

 

I reached out to BlackBear and waiting to hear back but was curious if anyone has done flex conversations with BlackBear tune and can chime in on experience.

With the sensor in and the FF table enabled you can run what ever fuel you want and the system will adjust according to the amount of ethanol in the system.  The reason for the sensor.  So if you ran several tanks of 93 then it would adjust for that fuel.  If you mixed then it would adjust for that. If you ran straight E85 then it would adjust for that and what BB set up the tune for to take advantage of the FF. 

 

Basically once you installed the sensor and let BB do their thing you can run what ever fuel you want and take advantage of it all.  No worries.

wforrest08 Senior Enthusiast

wforrest08

Posted
Posted (edited)
5 hours ago, Stonehenge said:

After I install the sensors/kit I am getting mixed messages.  BlackBear will turn on the ability to run E85 via a tune update.  Is this all that is needed to reap benefits from e85?  I want flex ability to swap between e85 and 93 pump without having to reflash a tune each time.  With this in mind what BlackBear is suggesting makes sense.  They offer a 91+ tune and turn on ability to run flex after the sensor is installed.  They are saying that the 91+ tune with flex option turned on is all that is needed to run E-85.  But will I see performance benefits this method or does this simply give me an option of running alternative fuel type?  I am getting  mixed messages, others are saying I need a tune specific for E85 to reap performance benefits.  

 

I reached out to BlackBear and waiting to hear back but was curious if anyone has done flex conversations with BlackBear tune and can chime in on experience.

My 5.3 1/2ton is a factory Flex I’m running only a Blackbear 91 tune in it and have been for the last 3 years. Yes I can definitely tell the difference between 91 and SUMMER BLEND E85. The factory fuel table is dependent on the alcohol content of your fuel. It will adjust the timing based on certain percentages of alcohol in the fuel. I forget of the top of my head what the %s are but there posted somewhere on here. So to take “full advantage” of E85 you have to hit the highest % the sensor senses think it’s around 70%. So if your tank is 3/4s full of 91 and you dump 1/4 of E85 in there you’re only going to hit the minimum % the sensor senses so it will only adjust the timing the minimum amount. But if you run your tank down to 1/4 on 91 and fill up with E85 twice your going to hit that 70%. I say summer blend cause winter blend E85 is a f’n joke at least here in the Midwest since it only has to be E70 by law. I don’t drive my 1/2 ton in the winter but a couple years ago it didn’t snow till mid December and we still had 70 degrees in November so I had been running E85 and refueled with E85 again but I could tell in less than 5 miles they had switched to winter blend cause it ran worse than on 91. I went with a 91 tune cause 93 is hard to find around here anymore and even 91 is scarce in some locations. I’m sure I might get a little bit more out of a dedicated E85 tune but this truck travels all over in the summer and I didn’t want to get stuck out somewhere with no E85 available and have to carry my auto-cal and reflash in the gas station parking lot and wait for it and reflash when I get home and... After all it’s a truck I’m not running it down the strip looking to gain a 10th or 2.

Edited by wforrest08
swathdiver Senior Enthusiast

swathdiver

Posted
Posted (edited)
8 hours ago, Stonehenge said:

After I install the sensors/kit I am getting mixed messages.  BlackBear will turn on the ability to run E85 via a tune update.  ...others are saying I need a tune specific for E85 to reap performance benefits.  

The factory tables for running E85/FlexFuel are already in the computer.  They are plenty robust for performance but can be tweaked for even more horsepower and efficiency through custom tuning of those tables.  Make sense now?  

 

3 hours ago, wforrest08 said:

My 5.3 1/2ton is a factory Flex I’m running only a Blackbear 91 tune in it and have been for the last 3 years. Yes I can definitely tell the difference between 91 and SUMMER BLEND E85. The factory fuel table is dependent on the alcohol content of your fuel. It will adjust the timing based on certain percentages of alcohol in the fuel. I forget of the top of my head what the %s are but there posted somewhere on here. So to take “full advantage” of E85 you have to hit the highest % the sensor senses think it’s around 70%. So if your tank is 3/4s full of 91 and you dump 1/4 of E85 in there you’re only going to hit the minimum % the sensor senses so it will only adjust the timing the minimum amount. But if you run your tank down to 1/4 on 91 and fill up with E85 twice your going to hit that 70%. I say summer blend cause winter blend E85 is a f’n joke at least here in the Midwest since it only has to be E70 by law. I don’t drive my 1/2 ton in the winter but a couple years ago it didn’t snow till mid December and we still had 70 degrees in November so I had been running E85 and refueled with E85 again but I could tell in less than 5 miles they had switched to winter blend cause it ran worse than on 91. I went with a 91 tune cause 93 is hard to find around here anymore and even 91 is scarce in some locations. I’m sure I might get a little bit more out of a dedicated E85 tune but this truck travels all over in the summer and I didn’t want to get stuck out somewhere with no E85 available and have to carry my auto-cal and reflash in the gas station parking lot and wait for it and reflash when I get home and... After all it’s a truck I’m not running it down the strip looking to gain a 10th or 2.

My truck calculates the alcohol content differently than you guys.  E85 can lawfully be anywhere from 51% to 83% alcohol.  Winter Blend for most places is 70% to allow for easier starting in cold weather.

 

I've been running E30 and have been getting even better tank averages with this stuff than on gasoline while saving nearly ten cents a mile in cost.  E30 is not supposed to drop lower than 25% but my supplier is usually pumping out 20-26% but the latest is 16% and it behaves little different than gasoline.  Most of the time when running pure E85 it is in the 72%-76% range but peak performance and the lowest mpg comes with 80%.

 

But, my particular Gen IV LC9 5.3 makes more power in the low 20s it seems and gets better gas mileage and right now it's so much less costly to run!  

 

Running 93 gasoline (BlackBear tuned) my cost per mile averages almost a quarter a mile, $.24 cents!  

 

Running E30 my cost per mile averages but sixteen cents a mile, $.16!  

 

That's a lot of money folks and free horsepower to boot. 

Edited by swathdiver
grammar
tyler.frost92 Enthusiast

tyler.frost92

Posted
Posted
23 hours ago, JONBLARC7 said:

one more

IMG_0714.jpg

Thanks for the pics, It doesnt look too terribly close to the driveshaft. Im sure if it bothered me i could get creative with some 90 degree fittings. But this is definitely the way I plan on doing it as opposed to $250+ kit. Instead of tapping the harness id probably spend a couple bucks on an extension since I have terrible luck with splicing and soldering. 

 

 

cap23.JPG

JONBLARC7 Enthusiast

JONBLARC7

Posted
Posted

I would have bought that too.  But I was in a hurry for some reason.  I should have bought that extension too but it's been on there for a few months now with no problems

 

 

 

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