what it takes to run E85
what it takes to run E85 im looking into running E85 cause its cheaper than race gas and i have seen a few people running it just looking for tips or hints or how you did it
Get something to tune with and learn how to use it, and be prepared to get worse mileage. Plus keep in mind that you just cant get as much power out of E85 as you can regular gas, energy in a gallon of fuel is measured in British Thermal Units, one gallon of gasoline has 124,000 BTU's, the same amount of E85 only has 81,800 BTU's. Sure the octane raiting is higher but is it really worth it?
I'm sure there are other people on here that can be of more help, the only thing I know about E85 is what was taught to me during my Ford factory training.
I'm sure there are other people on here that can be of more help, the only thing I know about E85 is what was taught to me during my Ford factory training.
Get something to tune with and learn how to use it, and be prepared to get worse mileage. Plus keep in mind that you just cant get as much power out of E85 as you can regular gas, energy in a gallon of fuel is measured in British Thermal Units, one gallon of gasoline has 124,000 BTU's, the same amount of E85 only has 81,800 BTU's. Sure the octane raiting is higher but is it really worth it?
I'm sure there are other people on here that can be of more help, the only thing I know about E85 is what was taught to me during my Ford factory training.
I'm sure there are other people on here that can be of more help, the only thing I know about E85 is what was taught to me during my Ford factory training.
Like I said I really dont know much about it and nothing in terms or performance. I was speaking specifically in terms of energy in the fuel its self, not power output on an engine running on it.
On a side note my wife's '02 civic (not an FFV) ran fine on a 50/50 mix of E85 and regular 87 octane. I mixed it back when gas was above $4 a gallon and the only negative effect was about a 4mpg decrease in mileage.
On a side note my wife's '02 civic (not an FFV) ran fine on a 50/50 mix of E85 and regular 87 octane. I mixed it back when gas was above $4 a gallon and the only negative effect was about a 4mpg decrease in mileage.
Last edited by Drumer919; Dec 19, 2008 at 03:18 PM.
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Check out this thread, it's got some good info...
https://ls1tech.com/forums/lt1-lt4-m...ctane-e85.html
https://ls1tech.com/forums/lt1-lt4-m...ctane-e85.html
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Verdad Gallardo The wot part of it would be easy to accomplish its the part throttle i see having a hard time with. Us lt1 guys dont have a option to change what the computer commands as stoich, the ls1 guys do.
Launching!
Joined: Dec 2002
Posts: 261
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From: ofallon mo
you will need a decent fuel pump and bigger fuel injectors. the tune will need to be reworked but its nothing too bad. you can run more timing which will get you more power and the added fuel helps cool the intake charge.
http://www.e85performance.net/forums/ might help
my budy is running it in his 95 and im going to run it once i hit the streets again.
http://www.e85performance.net/forums/ might help
my budy is running it in his 95 and im going to run it once i hit the streets again.
65# injectors, fuel pumps, and tunercats. assuming your car is tuned already, fill it with e85 and drop your injector constant until you get back to 14.7:1 in open loop on your wideband. go through and tune using your wideband and 1/4 MPH as usual
Yeah its not too hard to run it, but a wideband I would say is a must. You need at least 30% larger injectors, or slightly larger. I liked the E85. The lower BTU's are made up for by adding fuel, thus the reason for the lower mileage. Due to the higher octane, it does like a higher compression, and that's when you will start seeing a little more power out of it as well as better mileage, plus it keeps your fuel system clean, and helps cool combustion temps. You also need to run a colder plug, I would say TR6 to start.
My LE3 headed 385, when built, will be running E85 around 12.1 DCR with a custom cam right about at 9.0 SCR shifting around 6500, so if worse case E85 ever disappears, I could switch back to premium without having to change out my cam or lower the compression. It will not be a daily driver either.
My LE3 headed 385, when built, will be running E85 around 12.1 DCR with a custom cam right about at 9.0 SCR shifting around 6500, so if worse case E85 ever disappears, I could switch back to premium without having to change out my cam or lower the compression. It will not be a daily driver either.
So what about E85's stoichiometric value being 9.765:1 how are you accomplishing that? Because running E85 at 14.7:1 is mighty lean for that fuel. Like i said ls1 guys can program there stoichiometric value to anything they want, ours is a consistent. The only time I have seen tuner cats tables being able to command a afr is in open loop. E85 max power lean is 8.4687:1
Come on guys, think a little bit. Narrow band O2 sensors do not detect air fuel ratios at all they only know stoich rich and lean regaurdless of fuel. With e85 you skew the fueling by telling it the injectors are about 30% smaller than they are so it holds them open longer and fuels it pretty much correctly if your current gas tune is already pretty good. Only other thing is to add to the wot % coolant table because e85 likes to run a little more enrichment than gasoline. This is something fairly easy to do with an lt1, I have done it plenty of times. The cars are generally always faster. Part throttle manners in closed loop are also usually better because alcohol maintains normal combustion at leaner lamda values than gasoline and it helps with part throttle surging.
Ok so what happens when the Stock narrowband o2 sensors see this excessively rich conditions and start cutting fuel back in closed loop. Ltft at 108 then your still not getting the proper afr.
so wait how is the stoichiometric ratio monitored? In the air/ fuel mixture, as registered by the o2 sensors? I'm trying to keep up guys this is good stuff and I'm interested in giving this a try in my Lt1. What other set back can you guys foresee, other than tuning issues. I think the larger injectors more psi fuel pump makes perfect sense.
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From: Decatur, TN (N-W of Athens)
As in previous discussions, I like to run around a 60:40 ratio MAX for Gas:E85. Anything more and the car starts running like ***. Now, two fold for my guesstimation ratio: 1) Max amount of E85 I can get before I stop noticing a little gain in assdyno performance and start getting issues, and 2) it's so friggen cheap 
As for the O2 issue JD mention, I would think if you could insert a resistor to counter that and get it back to thinking it's 14.xx:1, then the computer wouldn't try to 'fix' the AF:R.
As for the O2 issue JD mention, I would think if you could insert a resistor to counter that and get it back to thinking it's 14.xx:1, then the computer wouldn't try to 'fix' the AF:R.
Your o2 sensors will not detect a super rich condition and will not correct when your injector constant is set an appropriate amount smaller. Listen to me very carefully, your pcm tunes to stoich be it straight gas e10 e20 e85 e100 methanol propane etc it is hard wired to tune to stoich it gives less than a **** what the chemicals are going in right along with the actual fuel ratio its using, its looking for oxygen content that signifies stoich fueling.
What you do is if you have 30lb injectors, you tell the pcm that you have 30% smaller injectors ie 21lb. This will make it keep them open long enough to supply 30% more fuel than it would with gasoline for the same airflow or ve. This will keep your fuel trims right near perfect 128 but you may have to tweak the constant somewhat experimentally to get them back to where they were with gas, it kind of depends on the engine and the injectors and winter or summer blend of e85 (I find 24-28% is on the button most of the time, it is very easy to zero in). The blms will work exactly the same as with gas but it is up to you to get them into the ballpark with the injector constant so you are not banging up against the max blm and it can actually adjust itself.
You do not need any fancy gimics or resistors or any other quick fixes. All you need is a tuner who has been around the block a time or two.
What you do is if you have 30lb injectors, you tell the pcm that you have 30% smaller injectors ie 21lb. This will make it keep them open long enough to supply 30% more fuel than it would with gasoline for the same airflow or ve. This will keep your fuel trims right near perfect 128 but you may have to tweak the constant somewhat experimentally to get them back to where they were with gas, it kind of depends on the engine and the injectors and winter or summer blend of e85 (I find 24-28% is on the button most of the time, it is very easy to zero in). The blms will work exactly the same as with gas but it is up to you to get them into the ballpark with the injector constant so you are not banging up against the max blm and it can actually adjust itself.
You do not need any fancy gimics or resistors or any other quick fixes. All you need is a tuner who has been around the block a time or two.
What he is trying to say is, that O2 sensors do NOT read air/fuel ratio, they read lambda, ie. stoich. When all the fuel is combined with all the free oxygen, typically within a vehicle's combustion chamber, the mixture is chemically balanced and this AFR is called the stoichiometric mixture. Stoich is stoich whether you are running gas, E85, methanol, etc. Narrowband O2's, as in stock O2's, only read stoich, they don't care what the fuel is, when they detect stoich, they report stoich. So the stock O2's will report lean if leaner than lambda, rich if richer. So if your car is running gas, at a perfect 14.7 A/F it will read lambda, and with E85 at 9.76 it will read the same thing. So basically to say that O2's measure the A/F ratio is not entirely accurate, they measure stoich and how far rich or lean the mixture is from stoich.
Given that we know that stoich for gas is 14.7, most widebands are programmed to display lambda as an A/F ratio and are programmed at 14.7 for stoich. So... if your gauge is programmed for gas, meaning at lambda the displayed A/F is 14.7 if you are running E85, at lambda, it will still read 14.7, unless you reprogram it to read 9.76 at lambda.
Given this info, as stated earlier, E85 max lean power enrichment mixture is typically 8.4687:1 A/F or .867 lambda, which if your wideband is still setup for gas, will read 12.75 at this mixture running E85 or .867 * 14.7. Although most people will agree that with E85, max power is usually around .82-.80 as there is not as much of a loss of power running a slightly rich with E85 as there is with gas.
Given that we know that stoich for gas is 14.7, most widebands are programmed to display lambda as an A/F ratio and are programmed at 14.7 for stoich. So... if your gauge is programmed for gas, meaning at lambda the displayed A/F is 14.7 if you are running E85, at lambda, it will still read 14.7, unless you reprogram it to read 9.76 at lambda.
Given this info, as stated earlier, E85 max lean power enrichment mixture is typically 8.4687:1 A/F or .867 lambda, which if your wideband is still setup for gas, will read 12.75 at this mixture running E85 or .867 * 14.7. Although most people will agree that with E85, max power is usually around .82-.80 as there is not as much of a loss of power running a slightly rich with E85 as there is with gas.