"Cant" run E85 on stock PCM? OK.. why cant we run this? - Page 3 - Tuning Forum

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Re:
Wednesday, April 17, 2013 7:31 AM
Just out of curiosity have any of you tuned other platforms than jbody? Meaning subarus, Grand prixs, srt's, or anything of that sort?

Re:
Wednesday, April 17, 2013 7:39 AM
Anyways to add some input to this. Locally in my area we have 1000k+ procharged non intercooled carb'd fox body on e85 who drive roughly 1k miles a month for 3 years now. We have a subie on e85 thats logged 40k miles that makes 450 awhp. The list goes on and on. Everyone is using e85 on almost every platform. I have an 87 GTA that has had e10 in the tank for about 6 years now. I through water remover in it and let it sit for the night. It started right up the next day no problem and i have no rust anywhere. True you should leave e85 sitting for long periods of time. Proper storage is putting fuel stabilizer in and pulling injectors and soaking them in gas or wd40 and cycle them on to prevent the black goo. The only time ive heard of it happening is in vehicles that arent regularly driven. Now thats about all i will touch on that subject until someone has something to say more then i'll add my input.
Re:
Wednesday, April 17, 2013 7:48 AM
Reverant GTP wrote:

Anyways to add some input to this. Locally in my area we have 1000k+ procharged non intercooled carb'd fox body on e85 who drive roughly 1k miles a month for 3 years now. We have a subie on e85 thats logged 40k miles that makes 450 awhp. The list goes on and on. Everyone is using e85 on almost every platform. I have an 87 GTA that has had e10 in the tank for about 6 years now. I through water remover in it and let it sit for the night. It started right up the next day no problem and i have no rust anywhere. True you should leave e85 sitting for long periods of time. Proper storage is putting fuel stabilizer in and pulling injectors and soaking them in gas or wd40 and cycle them on to prevent the black goo. The only time ive heard of it happening is in vehicles that arent regularly driven. Now thats about all i will touch on that subject until someone has something to say more then i'll add my input.






Edited 1 time(s). Last edited Wednesday, April 17, 2013 11:08 AM


FU Tuning



Re:
Wednesday, April 17, 2013 8:16 AM
I'm currently learning Nistune. Its not terribly hard as long as you understand the basics of how an engine functions. Nistune doesn't seem to have the limitations John was explaining to me about the J-body ECU. I'm able to command whatever AFR I want, and view it in either Lamda or standard AFR. It seems when guys on my platform run e85 they disable o2 feedback (closed loop) and just tune for the AFR's they want. Gas mileage can suffer a bit but they don't have drivability issues. Some newer Nissan ECU's allow for the o2 voltage calibrations to be adjusted so they can run closed loop with e85. My platform unfortunately doesn't support that.

Setting up a carb for E85 is much easier than fuel injection. With a carb all you need is the proper jetting for AFR's. So long as you have e85 compatible fuel lines and alcohol safe carb kit you are good to go. That isn't even a good comparison. As for gas sitting in the tank, I've had it go bad in a few months or this last time my car sat for about year and a half and it fired up and ran on the crap that was in the tank. However my very white car had huge amounts of what can only be described as black mold all round the gas door. My old man who has been building race cars for years, gas and alcohol, told me that is from the ethanol.
Re:
Wednesday, April 17, 2013 8:17 AM
Next on to tuning aspect of it all. Several other platforms tune using standard gas afr's rather than tuning in lambda or e85 values. There is nothing wrong with this and you guys are making it harder than it needs to be. First off oxygen sensors read off of the oxygen content in the exhaust stream and try to achieve lambda 1.0. Ok still with me? Lambda 1.0 IS.. i stress that again IS stoich NO MATTER WHAT THE FUEL BEING USED. The o2 sensor sends this info to the pcm it gets converted to afr. Ok what is afr? AFR is a correction of lambda. With me so far? AFR IS A CORRECTION OF LAMBDA... lambda 1.0 is 14.7 gas... lambda 1.0 is 9.76 e85... lambda is lambda is lambda and 1.0 is stoich. So take 14.7 afr for gas and divide that by 1.5= 9.8 afr for e85. Regardless of what your laptop screen says, regardless of what your afr gauge says... AFR is a correction of lambda... and lambda is what and oxygen sensor reads. Stop trying to over complicate things by trying to think of afr and millivolts.

Ok now what most self tuners of other platforms do to switch to e85 is change injector settings. ALOT use the k.i.s.s. (keep it simple stupid) method and tune their car on gas then change injector constant and call it good. From there you can add timing or just leave it alone and you will be fine! E85 is extremely forgiving and can run alot more rich or lean with tons of timing and not have an issue. This is most likely due to the fact of having 28-40% more fuel in the chamber plus the avg 105 octane.

Think of it this way... a flex fuel vehicle is by no mean nowhere near optimized to run on e85. I have a 2002 tahoe... i have no fancy heaters (as some of you ive seen post). Sure it does have stainless lines and an alchohol content anaylyzer. Regardless though it is not optimized at all... i have problems starting in the winter, every e85 car does whoopty doo. No the point of me bringing up this is changing the injector constant will get you in the ballpark just as a flex fuel is. Bringing the timing up will get you even closer than a flex fuel can even get. The manufacturer doesnt want to take the risk cuz obviously they have a name to protect so they get you in the ball park with flex fuel.

Ok i get it that everyone on here is concerned about its not the right way. Ok he's not trying to make 2000k horsepower... he's making what 250... if a carb can run e85 think about it, so can you. The tables you cant adjust or dont even have are way more optimized at every rpm level than any carb could ever be.

Next point e85 adds power to EVERYTHING... i'm pretty sure even in my gm manual in my tahoe it list the power going up on e85. As far as driving i can feel the difference not to mention i can do a burnout on e85 and on 87 octane i can barely chirp them. With zyaa possibly running his m45 over its efficiency he will need the cooler cylinder temps and higher octane to keep everything in check. When and if his eaton is over its efficiency it will produce high heat causing torque to go up and hp to drop along with pressure variances... his motor will want the benefits of e85 to offset his possible diminishing return.

Sorry i know i typed alot and probably out of order but i will await a reply and try to help clarify things as you retort. Thanks for your time.
Re:
Wednesday, April 17, 2013 8:27 AM
Addicted to meth wrote:

Brad our cars do not read in Lamba. They do not.
Our cars read in AFR. It converts the O2 sensor signal to AFR.


This Brad is what is 100% the truth. Our O2 sensors do not output lambda at all. They read strictly in volts and are converted directly to AFR. The Computer has absolutely no programming at all for lambda....at least nothing we can see, read, or infer. The brothers 2010 LNF cobalt reads in Lambda, and then converts it to AFR. They also have tables to modify the AFR to what ever they want....within limit.s That is why the cobalt people can get away with running E85, and we can not.


I know by definition that our sensor is a Lambda sensor. I agree 1000%, but our PCM just sees it as a voltage range which is then hard coated / programed to output a AFR. There is no interpolation at all. Most all other cars read in lambda. That is the best way I can explain it, to the best of my understanding.


Now back to your device. Could you get your car to run on E85, Yes!, would it run within the proper AFR for E85 yes...you can adjust the potentiometer to make it correct. The problem is E85 at one pump is not E85 at another. It has such a large window of makeup, and it varies a lot more than it should just by the "standards" it is made to. You can get it dialed in at X pump on X day, and it will run @!#$ perfect. As soon as you swap pumps, fill up your tank you may be 15-35% off the last fill up. Without a sensor that monitors the amount of Ethonal mix you are getting I wouldn't run E85. I'm positive you can get it to work, but I think you probably are going to have to adjust it "ALL THE TIME."


Added:
Brad your one of the most anal people I know. At best this is a band aid, I would think you would want to do it 100% correctly, and not a get-r-done kind of way.









Edited 1 time(s). Last edited Wednesday, April 17, 2013 8:37 AM


Re:
Wednesday, April 17, 2013 8:53 AM
An oxygen sensor IS IS IS a lambda sensor... you do not have some kind of special sensor that is different from any other oxygen sensor. It reads the content and sends a signal to the pcm. AFR is only calculated from lambda. Can you calculate it from mv.. sure but it is in noway near accurate not to mention NOBODY used mv to calculate afr. EVERYONE uses lambda to convert to and AFR.
Re:
Wednesday, April 17, 2013 8:56 AM
Lambda and millivolts are not the same.... Christ. The ECU has a conversion table that tells it what voltage correlates to what the mixture is. Some ECU's allow you change the tables, others don't. A narrow band only knows 3 things. Stoich, rich and lean and that is going by its programmed table. An example, basically it knows anything less than .35v is lean and anything above .65 is rich and between them two is stoich. So its not even spot on. If you have a wideband, have you ever noticed in closed loop your AFR (on gas) bounce around from about 13.9 to 15.2? That's because of the lack of resolution a standard o2 sensor has and what it considers stoich.
Re:
Wednesday, April 17, 2013 8:57 AM
A carburetor in no way, shape, or form is near as to close as perfect at every rpm as a fuel injected motor. The point i was trying to make with bringing this up is everyone on here seems to think the motor is just going to blow up cuz the afr is going to change at such n such rpm. That simply is not true... if you change the injector it will compensate the entire rpm range. A wideband will show everything will be ok.... and if its not then change back to 91 tune. Its not rocket science as some of you make it out to be.
Re:
Wednesday, April 17, 2013 8:59 AM
Reverant GTP wrote:

Next on to tuning aspect of it all. Several other platforms tune using standard gas afr's rather than tuning in lambda or e85 values. There is nothing wrong with this and you guys are making it harder than it needs to be. First off oxygen sensors read off of the oxygen content in the exhaust stream and try to achieve lambda 1.0. Ok still with me? Lambda 1.0 IS.. i stress that again IS stoich NO MATTER WHAT THE FUEL BEING USED. The o2 sensor sends this info to the pcm it gets converted to afr. Ok what is afr? AFR is a correction of lambda. With me so far? AFR IS A CORRECTION OF LAMBDA... lambda 1.0 is 14.7 gas... lambda 1.0 is 9.76 e85... lambda is lambda is lambda and 1.0 is stoich. So take 14.7 afr for gas and divide that by 1.5= 9.8 afr for e85. Regardless of what your laptop screen says, regardless of what your afr gauge says... AFR is a correction of lambda... and lambda is what and oxygen sensor reads. Stop trying to over complicate things by trying to think of afr and millivolts.

Ok now what most self tuners of other platforms do to switch to e85 is change injector settings. ALOT use the k.i.s.s. (keep it simple stupid) method and tune their car on gas then change injector constant and call it good. From there you can add timing or just leave it alone and you will be fine! E85 is extremely forgiving and can run alot more rich or lean with tons of timing and not have an issue. This is most likely due to the fact of having 28-40% more fuel in the chamber plus the avg 105 octane.

Think of it this way... a flex fuel vehicle is by no mean nowhere near optimized to run on e85. I have a 2002 tahoe... i have no fancy heaters (as some of you ive seen post). Sure it does have stainless lines and an alchohol content anaylyzer. Regardless though it is not optimized at all... i have problems starting in the winter, every e85 car does whoopty doo. No the point of me bringing up this is changing the injector constant will get you in the ballpark just as a flex fuel is. Bringing the timing up will get you even closer than a flex fuel can even get. The manufacturer doesnt want to take the risk cuz obviously they have a name to protect so they get you in the ball park with flex fuel.

Ok i get it that everyone on here is concerned about its not the right way. Ok he's not trying to make 2000k horsepower... he's making what 250... if a carb can run e85 think about it, so can you. The tables you cant adjust or dont even have are way more optimized at every rpm level than any carb could ever be.

Next point e85 adds power to EVERYTHING... i'm pretty sure even in my gm manual in my tahoe it list the power going up on e85. As far as driving i can feel the difference not to mention i can do a burnout on e85 and on 87 octane i can barely chirp them. With zyaa possibly running his m45 over its efficiency he will need the cooler cylinder temps and higher octane to keep everything in check. When and if his eaton is over its efficiency it will produce high heat causing torque to go up and hp to drop along with pressure variances... his motor will want the benefits of e85 to offset his possible diminishing return.

Sorry i know i typed alot and probably out of order but i will await a reply and try to help clarify things as you retort. Thanks for your time.





Edited 1 time(s). Last edited Wednesday, April 17, 2013 11:11 AM


FU Tuning



Re:
Wednesday, April 17, 2013 9:00 AM
I think you need to read this.

http://www.howstuffworks.com/question257.htm

Most specifically this

The oxygen sensor is positioned in the exhaust pipe and can detect rich and lean mixtures. The mechanism in most sensors involves a chemical reaction that generates a voltage (see the patents below for details). The engine's computer looks at the voltage to determine if the mixture is rich or lean, and adjusts the amount of fuel entering the engine accordingly.

See that? voltage! The voltage has a table assigned to it in the ECU that translates what it correlates too. The sensor reads nothing at all...

Re:
Wednesday, April 17, 2013 9:04 AM
Its not a lack of resolution.. it is how a narrow band is supposed to work. An oxygen sensor which by another name is a LAMBDA sensor... As long as the wiring is the same the oxygen sensor works the same regardless the application. Ever heard of or used a universal o2 sensor? They work just fine when wired in correctly. By nature an o2 sensor purpose is to achieve lambda 1.0 which is stoich with is around 450 mv. You will never see a narrow band working properly stick at the same mv.. they are intended to switch back and forth lean to rich in order to work properly.
Re:
Wednesday, April 17, 2013 9:06 AM
Lets switch it up then and see if anyone can understand this.... It is recommended by most whom convert to e85 to only change injector constant. They dont change their commanded afr... they dont change anything closed loop. They work great, no problems, no hiccups and only reap benefits of ethanol.... Explain why.
Re:
Wednesday, April 17, 2013 9:07 AM
I should add your platform is not the only one who cant change commanded afr. Yet they still run e85.
Re:
Wednesday, April 17, 2013 9:09 AM
I can understand why the last person who ran e85 melted their motor with the thinking of this group. You all are trying to way over complicate e85 tuning.
Re:
Wednesday, April 17, 2013 9:13 AM
I love magic sensors! I'm glad you have one. My magic ECU allows me to use either scale because the software has conversion tables for both! And I love how you are trying to compare carbs to EFI. You make me smile.
Re:
Wednesday, April 17, 2013 9:15 AM
Fuel
AFR FAR Equivalence
Ratio Lambda
Gas stoich 14.68 0.068 1.000 1.000
Gas max power rich ~12.5 0.080 1.176 0.8503
Gas max power lean ~13.2 0.0755 1.111 0.900

E85 stoich 9.87 0.101 1.000 1.000
E85 max power rich ~6.98 0.1434 1.40 0.7143
E85 max power lean ~8.47 0.118 1.153 0.8673

E100 stoich 9.00 0.111 1.000 1.000
E100 max power rich ~6.43 0.155 1.40 0.714
E100 max power lean ~7.80 0.128 1.150 0.870
Re:
Wednesday, April 17, 2013 9:18 AM
Lets try working backward then... 14.7 is stoich... stoich is lamda 1.0... lambda 1.0 is 450mv.... stoich afr is mathematically figured off of lambda 1.0 not off mv. How does a computer know what fuel is being used? It doesn't... it only knows to create 450mv i need this much oxygen.
Re:
Wednesday, April 17, 2013 9:19 AM
Well if its simple why is Brad the guy that knows all wanting to run a bandaid box?
Re:
Wednesday, April 17, 2013 9:21 AM
stoich is a ratio of oxygen and fuel.... stoich is used to achieve a number of oxygen the sensor needs to see to output 450 mv
Re:
Wednesday, April 17, 2013 9:23 AM
Then hell he doesn't even need to tune. He just needs to throw in 40% bigger injectors and it should start up and run just fine! Its just like a carb!

Re:
Wednesday, April 17, 2013 9:26 AM
lets use the table posted... stoich of gas is 14.68 to reach a level of lets say oxygen 1.0... 1.0 is the level of oxygen a sensor needs to see to output a voltage to the pcm that it wants to see.
Now this applies to any fuel... e85 needs a ratio of 9.87 to reach 1.0 oxygen level... e100 needs a ratio of 9.00 to reach oxygen level 1.0..... that level of 1.0 is all an o2 sensor wants to see... that in turn is sent to pcm... "hey pcm i have 1.0 here" "pcm says hey ok, thanks" now lets say pcm say " he i have 1.1 here" pcm says thats not right!" ok my tables say i need this and then "magic happens" and the pcm changed fuel to achieve that 1.0 again.
Re:
Wednesday, April 17, 2013 9:30 AM
Reverant GTP wrote:

An oxygen sensor IS IS IS a lambda sensor...

agreed
Reverant GTP wrote:

It reads the content and sends a signal to the pcm.

yep
Reverant GTP wrote:

AFR is only calculated from lambda.

kinda but ours is outputted in volts in a non-linear relationship to lambda.
Reverant GTP wrote:

EVERYONE uses lambda to convert to and AFR.

tell that to our PCMs...
Reverant GTP wrote:

The point i was trying to make with bringing this up is everyone on here seems to think the motor is just going to blow up cuz the afr is going to change at such n such rpm. That simply is not true... if you change the injector it will compensate the entire rpm range. A wideband will show everything will be ok.... and if its not then change back to 91 tune. Its not rocket science as some of you make it out to be.

nope...didnt say blow up...just not run correctly.
Reverant GTP wrote:

I should add your platform is not the only one who cant change commanded afr. Yet they still run e85.

Agreed, but they read in lambda and output in lambda....
Reverant GTP wrote:

I can understand why the last person who ran e85 melted their motor with the thinking of this group. You all are trying to way over complicate e85 tuning.

No he tried to tune with his AFR, simply like you stated.
Reverant GTP wrote:

Lets switch it up then and see if anyone can understand this.... It is recommended by most whom convert to e85 to only change injector constant. They dont change their commanded afr... they dont change anything closed loop. They work great, no problems, no hiccups and only reap benefits of ethanol.... Explain why.

Open a J-body file in HPTuners or EFI live. Then open a GTP file. The J-body file has maybe a 1/5 of the tables/settings the GTP has.


Added: I do not think anyone of us are saying it can not be ran on E85....what were are saying it is not the proper/correct way, and really not even a truly safe way of doing it.





Edited 1 time(s). Last edited Wednesday, April 17, 2013 9:34 AM


Re:
Wednesday, April 17, 2013 9:30 AM
john, yes i love doing things the right way. you know i do. but in this case, doing it the "right" way would mean having me buy some sort of standalone PCM, PAYING someone to wire it up... and PAYING someone to tune it out. mind you this would probably range anywhere from 1000-2000 dollars. it is simply NOT worth it for the m45 and a measily 40whp if i am lucky. so yes, in this case "you got me" OMGZ i wanna do something "WRONG!" the heaven's are falling. look out.

do you feel better out yourself, now? the ONLY thing i can think if that i have given you @!#$ about not doing "right" was the aem alternator pulley. which, cutting a 10 rib belt down to "make it work" in my book is cheesy. i got a 5 rib on my car because i looked outside the box and tried something NOBODY else had. it worked out great. i have a 5 rib off the shelf option and it works flawlessly. now, if i have "hurt your feelings" over something else ive given YOU crap over. then i apologize. but this "i wanna get back at brad" nonscience is quite childish.

i have already decided against using the conversion box. why? because we can do it without it the same exact way. id rather give the tuner that 300 bucks to get my tune closer to the best it can be.

with that said, i am finished with this thread. i am going to run e85, if it blows up, oh well... at least i tried something new, which in the case of our community goes is something we all desperately need to do to at least try and keep up with the rest of the world.



It's nice to be injected but I love being blown.
Re:
Wednesday, April 17, 2013 9:33 AM
The tables still need to add 28-40% more fuel through injector constant in order to change the magic invisible tables. My goodness man do more research this isnt the first time this has been done only using injector constant. Some use adjustable fuel pressure regulators in conjunction with injector constant and make great power. Like i said its not rocket science, its not voodoo, break out of the jbody crowd and learn how various other platforms accomplished it.... if others have done it, so can you guys.
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