I need some help on what your setup is to run E85
Edited 1 time(s). Last edited Saturday, October 20, 2012 11:28 PM
13.1 @ 115
I'm not aware of anyone sucessfully running e85 on a stock pcm. It's a pretty big risk at this point given the tables available in HPT. Leafy is convinced that it can be done, but when you're talking about changing to a fuel that at any given point on the map demands at least 1/3 more fuel mass, it's kind of tough to commit w/o all the right tables.
If i was to even think of a way to attempt this, the first step would be lots of extra injector. If you run 42 lbs on gas, plan on at least 60lbs on e85. Next, i would probably have to committ to ditching closed loop. The way Leafy theoretically described tuning it was to tune the extra fuel mass via the injector constant and trust the narroband in closed loop. I just don't have that trust until i see it, and i don't know what other implications there are in fudging fuel trims via the injector constant. Next, you have to be ready to deal with cold starts if you live in a region where it gets frigid. We don't have a cranking spark table, and e85 is notoriously known for being b1tchy in cold weather, so there is some sacrifice there.
Bottom lilne is most pros would not recommend it on a jbody pcm. Stand alone is a different story.
Well hmm...injector wise I'm already running 60s but I understand what you mean by the tune and yeah I live in indiana so its cold every morning lol
13.1 @ 115
You "MIGHT" be able to get away with tuning in a 50/50 mix e85/91piss gas (I'd start with a 20% mix), "MAYBE". From what I've seen the only time the full e85 is really needed is running big amounts of boost. My egt's under 21psi boost never go over 1350*. But I'm running a full standalone system.
"The FACTS are always subject to CHANGE once the TRUTH is applied"
"In the entire history of man the only stupid questions are the ones that don't get asked"
Dual-mapping is the way to go, I say... Plus, look-around to find a shop anywhere that does flex-fuel conversions. I've read in Popular Hot-Rodding about a shop that takes the inline sensor GM uses & adds it to any factory computer (OBD-I or II) via "unused" input terminals, so there's a possibility.
Go beyond the "bolt-on".
^^ I saw that also but the other concern I have is are a stock fuel lines even strong enough to hold e85 theres horror stories about hondas switching and it eating through there fuel lines lol
13.1 @ 115
That's just a matter of materials used... Change what fuel-system parts aren't compatible with ethanol with ones that are & you'll be fine. This is where doing the most research possible is good.
Go beyond the "bolt-on".
it can be done, but people here tend to not know how to use their tuning software, nor how to setup a fuel system.
-Trailblazer SS - not so custom 6.0L - custom intake - custom tune
- (1) 2.4L on an engine stand (1) blown trans (2) good quad trans (1) eco trans = party
oldschool, why no love for the narrowband? No matter what fuel you put in the car its going to give the same reading at stoich. It doesnt care about fuel at all, just how much free oxygen is left in the exhaust pipe. I have some testing I want to do related to cranking advance, but I'm going to have to buy a new hpt cable since my disappeared.
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^That is correct! The makeup of the classic narrow-band is platinum & zirconia, with combined generates a low voltage (0-1v) while in the presence of oxygen. The first GM-used Bosch digital fuel-management systems were all just variants of the Bosch Lamba-Sond K-Jetronic system (intro'd '77) the determined the fuel amount required at any given moment during non-full-throttle operation by reading the voltage generated, then adjusting the metering slightly one way or the other several times a second, in order to try to maintain a voltage level of a certain ideal (Usually about 0.7v).
Go beyond the "bolt-on".
I realize that, but don't take the NBO2 statement out of context. I also said we don't know the implications of fudging the fuel trims via changing the injector constant. I'm excited to see what you come up with.
The other thing that in the pipeline is borrowing my friends tactrix cable and see if I can make my own definition for this car in Rom Raider, then I get stuff hpt cant do and I'll say screw the hpt cable and buy a 100 dollar tactrix cable instead. But who knows if that cable and ecu flash will even read our pcm.
1994 Saturn SL2 Home Coming Edition: backup car
2002 Chevy Cavalier LS Sport Coupe: In a Junk Yard
1995 Mazda Miata R-package Class=STR
Sponsored by:
Kronos Performance
WPI Class of '12 Mechanical Engineering
WPI SAE Risk and Sustainability Management Officer
well if you figure something out let me know..ive been looking at switching for a while now to be more safe on my engine lol
13.1 @ 115
my boosted 98 z24 is tuned on e85 and it runs and pulls hard. my hp numbers and torque was very impressive. it can be done safely with HPT. anyone that wants to do this or has been thinking about doing it...DO IT!
See guys I told you you could do it. I even told you how. @!#$ now that I'm going to be rocking the 2.4 swap I should try and look for e stations around here again, buy a racetronic pump and some 80 lb'ers.
1994 Saturn SL2 Home Coming Edition: backup car
2002 Chevy Cavalier LS Sport Coupe: In a Junk Yard
1995 Mazda Miata R-package Class=STR
Sponsored by:
Kronos Performance
WPI Class of '12 Mechanical Engineering
WPI SAE Risk and Sustainability Management Officer
Only thing that has been stopping me from going e85 is the lack of fueling stations by me.
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same here....i would LOVE to convert...nothing stopping me....other than the fact the capitol city of texas only has 1 e85 station....and that one is pretty far from my house...not to mention if i have to go outta town.
Leafy wrote:oldschool, why no love for the narrowband? No matter what fuel you put in the car its going to give the same reading at stoich. It doesnt care about fuel at all, just how much free oxygen is left in the exhaust pipe. I have some testing I want to do related to cranking advance, but I'm going to have to buy a new hpt cable since my disappeared.
Yeah but remember stoich on gasoline is 14.7 E85 is 9.765. So the j computer will be commanding a stoich afr that in reality is extremely lean for e85.
No the narrow band tells the computer the car is ruining at/high/low stoich, whether stoich is 14:1, 9.8:1 or over 9000:1.
1994 Saturn SL2 Home Coming Edition: backup car
2002 Chevy Cavalier LS Sport Coupe: In a Junk Yard
1995 Mazda Miata R-package Class=STR
Sponsored by:
Kronos Performance
WPI Class of '12 Mechanical Engineering
WPI SAE Risk and Sustainability Management Officer
Club Teh Jeffie wrote:Only thing that has been stopping me from going e85 is the lack of fueling stations by me.
this we dont have very many E85 stations in FL so its 93 for now and if i need it down the road race fuel
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This thread cracks me up......
P&P Tuning
420.5whp / 359.8wtq
Why's that? Because you don't think its possible? We have the exact same controls that are related to this that the lnf guys just got and they can do it. they too only have an injector constant and no ability to change the computers stoich value.
1994 Saturn SL2 Home Coming Edition: backup car
2002 Chevy Cavalier LS Sport Coupe: In a Junk Yard
1995 Mazda Miata R-package Class=STR
Sponsored by:
Kronos Performance
WPI Class of '12 Mechanical Engineering
WPI SAE Risk and Sustainability Management Officer
Leafy (Club Jeffie FEA man) wrote:Why's that? Because you don't think its possible? We have the exact same controls that are related to this that the lnf guys just got and they can do it. they too only have an injector constant and no ability to change the computers stoich value.
No we don't! The LNF also commands EVERYTHING in Lambda... Our PCM coding does not! Adding these factors and knowing we have no STOICH control, this is just a recipe for disaster. I have tuned sh!tloads of both (LNF and Jbody) and I know what does and does not work. Anybody attempting to do this should be be warned! Can you run E85 on a Jbody PCM, YES! Can you do it RELIABLY AND SAFELY, NO! Now I get that you are learning EFI Leafy, and I applaud you for wanting to learn.... But fact is, you still have a lot to learn about it. You need some real world experience doing more before you start telling people what can/can't be done. Lets face it, Jbody owners are a bunch of cheap @sses that want everything handed to them (including tuning).. Most people also do not do research like you do, and tend to read something and jump on it without knowing any of the real consequences....
P&P Tuning
420.5whp / 359.8wtq
I still don't know how it can tell its at 14.7 or 9.8, do we use some sort of o2 sensor that I've never heard of? All narrow bands that I've ever heard of can only tell you if the car is running at, not what the actual afr is. Hell, wide bands can't even do that, you need a 5 gas analyzer to do that.
1994 Saturn SL2 Home Coming Edition: backup car
2002 Chevy Cavalier LS Sport Coupe: In a Junk Yard
1995 Mazda Miata R-package Class=STR
Sponsored by:
Kronos Performance
WPI Class of '12 Mechanical Engineering
WPI SAE Risk and Sustainability Management Officer
