E85 Conversion
Burning Brakes
Joined: Nov 2013
Posts: 1,036
Likes: 119
I think the issue comes when you try to do flex fuel. I know I could tune it for e85, ONLY fill it with e85, and be golden. The problem is, there are only 2 or 3 stations in town with e85, and it gets REAL spotty outside of town. (strange since I'm right in the middle of the corn belt) Also, they change the blend pretty drastically from summer to winter, and I still drive my car in the winter as long as there isn't snow. I think I've read it goes all the way down to ~40% ethanol in my area.
Melting Slicks
Joined: Feb 2001
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From: Northville, MI
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2020 Corvette of the Year Finalist (performance mods)
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ok I see, from what I understand you can still use an older truck pcm along with some wiring modifications and a sensor to make flex fuel work on the c5... I have enough stations around me and I don't go on long trips so I have chosen to just run e85 full time for now
Intermediate
Joined: Mar 2019
Posts: 43
Likes: 3
From: NYC
Hey guys, sorry for the late response. I had completely forgot about this thread. The install was a breeze. I did not use the fuel lines that were sent with the kit. I used aftermarket lines with new added fuel rails so the ethanol sensor was installed. The main injector harness plugs in between the injectors and the injector connectors. Install your ground and install the commander unit and that’s it. I’m in the middle of a tune so I haven’t had time to see what this kit can do. But I will for sure chime in on it once I do
Thread Starter
Melting Slicks
Joined: Mar 2018
Posts: 2,502
Likes: 187
From: California
Sorry for late get back all. I still haven’t pulled the trigger on it. Although with the new booster application I think I would need at least 100lb injectors to keep up with demand. I also have one more variable the methanol injection. Kit claims 91 to 116 octane increase. E85 plus methanol injection = what octane level? Got the bap,58psi jet pump. @ Jett’s how is it? Noticeable gains?
Last edited by Speedy007; May 26, 2019 at 03:16 AM.
Thread Starter
Melting Slicks
Joined: Mar 2018
Posts: 2,502
Likes: 187
From: California
Was reading something with e85 how methanol is a great insurance policy for knock control especially with boosted cars. How did you do your setup ? Did you use the proflex or similar? Just put in a flex fuel sensor and re tune ?
Last edited by Speedy007; May 26, 2019 at 01:52 PM.
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that is true, more so for pump gas, but e85 has about the same octane as methanol and if you aren't seeing knock with e85 then adding meth on top of that is just going to add unnecessary octane and richen your afr... just as an example my car was at 16 degrees of timing with 93/meth and we were able to bump that up to 22 degrees safely with e85 and no meth... I believe my tuner actually went to 24 degrees on the dyno but it wasn't picking up much power past 22 degrees, at that point the risk isn't worth the reward on a street car so he backed it down to 22... even at 24 degrees there was no knock... I am not running a flex setup, it's tuned on e85 and I monitor the content and watch my widebands to make sure the afr doesn't fluctuate too much, the place I buy mine from is fairly consistent so I haven't had any issues... I built a boost referenced system with twin walbro 450s in the tank and 1650cc injectors... you don't need a flex sensor if you are going to tune it on e85 and leave it alone, you only need that sensor with a flex setup so the pcm knows the content to be able to adjust the tune on the fly
Heel & Toe
Joined: May 2018
Posts: 18
Likes: 8
Figured this was worth posting on this thread, I recently did a PCM swap to gain all the benifits including my car adjusting the timing accordingly.
https://www.corvetteforum.com/forums...onversion.html
https://www.corvetteforum.com/forums...onversion.html
Advanced
Joined: Dec 2017
Posts: 65
Likes: 30
Just an FYI, Grassroots Motorsports just installed the Proflex kit on their project C5Z and dyno'd 15hp, 18lbsft additional. No, it didn't require new injectors or fuel pump or ECU or all the other scary stories. 40 minute install, no cutting of wires, and it includes the flex fuel sensor so it is fully compatible with variations in alcohol content. Grassroots is a non-biased and honest mag so i trust their feedback. Granted, if you're already modified and pushing the limits of your fuel system, this will likely be a non-starter.
On a side note, for all the folks wondering what magic this does to override the ECU, it simply takes the incoming injector signal and increases the pulse width as needed based on alcohol content.
On a side note, for all the folks wondering what magic this does to override the ECU, it simply takes the incoming injector signal and increases the pulse width as needed based on alcohol content.
Heel & Toe
Joined: May 2018
Posts: 18
Likes: 8
Just an FYI, Grassroots Motorsports just installed the Proflex kit on their project C5Z and dyno'd 15hp, 18lbsft additional. No, it didn't require new injectors or fuel pump or ECU or all the other scary stories. 40 minute install, no cutting of wires, and it includes the flex fuel sensor so it is fully compatible with variations in alcohol content. Grassroots is a non-biased and honest mag so i trust their feedback. Granted, if you're already modified and pushing the limits of your fuel system, this will likely be a non-starter.
On a side note, for all the folks wondering what magic this does to override the ECU, it simply takes the incoming injector signal and increases the pulse width as needed based on alcohol content.
On a side note, for all the folks wondering what magic this does to override the ECU, it simply takes the incoming injector signal and increases the pulse width as needed based on alcohol content.
Awesome! Although I don’t think you will get the full Benefits of the flex fuel, does this kit adjust the ignition timing in correlation with the ethanol content? Because that’s the BIGGEST benefit in my opinion
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exactly, if it can't adjust timing why bother?... at that point it would not be worth the money or effort in my opinion, if you just want to say you're running e85 and have your exhaust smell good then this would work
Heel & Toe
Joined: May 2018
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Advanced
Joined: Dec 2017
Posts: 65
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You’re right, it doesn’t adjust timing. It simply allows the ecu to run the higher timing values in its maps more frequently because it won’t see KR. You can still benefit by bumping up the timing across the board. The controller then just adds more fuel. It’s not a true closed-loop flex fuel system, but an intermediate option.
But, that $900 price tag is a bit outrageous. I also wonder about corrosion within fuel components that were not designed for E85...
But, that $900 price tag is a bit outrageous. I also wonder about corrosion within fuel components that were not designed for E85...
Heel & Toe
Joined: May 2018
Posts: 18
Likes: 8
You’re right, it doesn’t adjust timing. It simply allows the ecu to run the higher timing values in its maps more frequently because it won’t see KR. You can still benefit by bumping up the timing across the board. The controller then just adds more fuel. It’s not a true closed-loop flex fuel system, but an intermediate option.
But, that $900 price tag is a bit outrageous. I also wonder about corrosion within fuel components that were not designed for E85...
But, that $900 price tag is a bit outrageous. I also wonder about corrosion within fuel components that were not designed for E85...
Drifting
Joined: Sep 2017
Posts: 1,959
Likes: 690
From: Avon Lake OH
One other thing most folks don't realized is that you need up to 30-35% more ignition energy to burn E85 than pump gas. It gets worst with colder ambient air temperatures and higher humidity. So one other thing to add to the list is swapping out the LS1/LS6 coils for the Gen III flex fuel truck coils, AC/Delco D585, aka the "Escalade coils", the ones with the aluminum heat sinks on top. Besides needing the coils, mounting brackets with the harnesses for the D585 swap you also have to run correct ignition dwell map for the D585 coils, which of course is different than for the stock LS1/LS6 coils. You have to down load that table when re-flashing the ECU, so you might as well start with the GM truck flex fuel ECU and use the tuner software of your choice.
Heel & Toe
Joined: May 2018
Posts: 18
Likes: 8
One other thing most folks don't realized is that you need up to 30-35% more ignition energy to burn E85 than pump gas. It gets worst with colder ambient air temperatures and higher humidity. So one other thing to add to the list is swapping out the LS1/LS6 coils for the Gen III flex fuel truck coils, AC/Delco D585, aka the "Escalade coils", the ones with the aluminum heat sinks on top. Besides needing the coils, mounting brackets with the harnesses for the D585 swap you also have to run correct ignition dwell map for the D585 coils, which of course is different than for the stock LS1/LS6 coils. You have to down load that table when re-flashing the ECU, so you might as well start with the GM truck flex fuel ECU and use the tuner software of your choice.
Drifting
Joined: Sep 2017
Posts: 1,959
Likes: 690
From: Avon Lake OH
Well maybe you can get away with the stock LS1/LS6 coils in warm dry weather. But when you look at the Gen III truck coils, you have the AC/Delco D585 found on the flex fuel trucks and the AC/Delco D581 found on the gasoline only trucks. There is a big different in energy output between these two coils. But keep in mind that GM has to make sure that the flex fuel truck engine will start in cold damp weather every time, even if the winter grade of E85 is actually only E50 or even less ethanol content.