Warning. This is experimental and theoretical, it has not been attempted on this platform. Just because it should work in theory doent mean it will.

Its actually quite easy. We will be modifying the the fuel injector constant in order to trick the PCM into supplying the correct amount of fuel without raping your VE maps.

Step 1:
Get your tune on 93 damn good. Your LTFT's should be 0 or damn close, all the time.

Step B:
Get the tank almost completely empty and then fill with e85.

Step III:
create a custom pid with the value [current injector constant]*[SENS.114]
Make a histogram with 1 cell with this value as the displayed value.

Step 4:
Once the car is filled with e85 drive aways from the pump and log your car until the fuel trims even out, they may not, if thats the case just wait for them to max out.
Stop logging and shut off the car.
Take the value from the histogram and past special add it to your fuel injector constant.
flash
If you maxed out your fuel trims repeat this step again

Step 4.5
Adjust pid to reflect new injector constant

Step E:
Now go drive around for a few hours.
Paste special that value again

Step E.5
repeat step 4.5

Step 6:
You should be good now, just tune like normal to take care of the STFT's.

This works for the LNF's which also happen to lack the proper values to tune for e85.

If any part of this is incoherent please let me know and I'll fix it tomorrow night. Right now I'm wacked on caffeine and I want to sleep so I though 4 shots of vodka in 5 minutes would help that and its not. So; wacked on caffeine and slightly drunk.



Edited 1 time(s). Last edited Wednesday, March 30, 2011 12:39 PM

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 wrote:Its actually quite easy. We will be modifying the the fuel injector constant in order to trick the PCM into supplying the correct amount of fuel without raping your VE maps.

Step 1:
Get your tune on 93 damn good. Your LTFT's should be 0 or damn close, all the time.

Step B:
Get the tank almost completely empty and then fill with e85.

Step III:
create a custom pid with the value [current injector constant]*[SENS.114]
Make a histogram with 1 cell with this value as the displayed value.

Step 4:
Once the car is filled with e85 drive aways from the pump and log your car until the fuel trims even out, they may not, if thats the case just wait for them to max out.
Stop logging and shut off the car.
Take the value from the histogram and past special add it to your fuel injector constant.
flash
If you maxed out your fuel trims repeat this step again

Step 4.5
Adjust pid to reflect new injector constant

Step E:
Now go drive around for a few hours.
Paste special that value again

Step E.5
repeat step 4.5

Step 6:
You should be good now, just tune like normal to take care of the STFT's.

This works for the LNF's which also happen to lack the proper values to tune for e85.

If any part of this is incoherent please let me know and I'll fix it tomorrow night. Right now I'm wacked on caffeine and I want to sleep so I though 4 shots of vodka in 5 minutes would help that and its not. So; wacked on caffeine and slightly drunk.

This is NOT the same as the LNF. Our PCM is not coded in Lambda like the PCM in the LNF, and we don't have the other injection window criteria...... Also, on the LNF, there are many other fueling tables that aid with this, mainly to keep the load factors correct because when you skew the MAF the load % is off. This is not as simple as you are trying to describe above... You are trying to compare apples to oranges here.... I would not advise this to anybody......






P&P Tuning
420.5whp / 359.8wtq

The LNF are now (will) using this rather than skewing maf.

I dont understand how our computers wouldnt be programed in lambda. They get lambda from the narrowband the narrowband doesnt output an afr. The computer has to be working in lambda. And all this is essentially doing is telling the computer that the injectors are ~30% smaller than they actually are so the car will basically give it more fuel based on the same VE map because it thinks the injectors are smaller. When in closed loop once tuned your wideband will still read around 14.7:1 because once again, thats a lambda sensor, It just reads lambda and then the wideband gauge converts lambda to afr based on the conversion you gave it.

And even if the computer doesnt use lambda, lets say for some retarded reason it converts lambda to afr or converts it to some units related to penis length, it doesnt matter what the units are, its still going to be based on a lambda measurement from either your narrow band in closed loop and your wideband in open loop (through your tune). Lambda is just a unit-less form of air to fuel ratio, if you give lambda units its still based on lambda. For instance, multiply lambda by 14.7 and you get the afr for gas, multiply by 9.7 and you get the afr for e85. But still its based on lambda. Does having an actual box to define your afr make life easier (like on the lsj)? Yes because you dont have to fool the computer into thinking the injectors are smaller, and that you dont have to do conversions in your head from the gas afr's to the e85 afr's every time you want to do something involving afr's on your car.

There is only 1 concern I have with this, and its only a minor one. Doing this could possibly make the minimum injector pulse width do funny things but I dont think it should be an issue.


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 wrote:The LNF are now (will) using this rather than skewing maf.

I dont understand how our computers wouldnt be programed in lambda. They get lambda from the narrowband the narrowband doesnt output an afr. The computer has to be working in lambda. And all this is essentially doing is telling the computer that the injectors are ~30% smaller than they actually are so the car will basically give it more fuel based on the same VE map because it thinks the injectors are smaller. When in closed loop once tuned your wideband will still read around 14.7:1 because once again, thats a lambda sensor, It just reads lambda and then the wideband gauge converts lambda to afr based on the conversion you gave it.

And even if the computer doesnt use lambda, lets say for some retarded reason it converts lambda to afr or converts it to some units related to penis length, it doesnt matter what the units are, its still going to be based on a lambda measurement from either your narrow band in closed loop and your wideband in open loop (through your tune). Lambda is just a unit-less form of air to fuel ratio, if you give lambda units its still based on lambda. For instance, multiply lambda by 14.7 and you get the afr for gas, multiply by 9.7 and you get the afr for e85. But still its based on lambda. Does having an actual box to define your afr make life easier (like on the lsj)? Yes because you dont have to fool the computer into thinking the injectors are smaller, and that you dont have to do conversions in your head from the gas afr's to the e85 afr's every time you want to do something involving afr's on your car.

There is only 1 concern I have with this, and its only a minor one. Doing this could possibly make the minimum injector pulse width do funny things but I dont think it should be an issue.

I understand how Lambda works, thats not what this discussion is about. You are trying to compare the recent LNF tables to the lack of tables in the Jbody PCM and thinking that would allow the Jbody PCM to properly run E85. These are too different systems and the Bosch PCM is much more complex. I have tuned MANY of both platforms. You bring up the LSJ PCM. With the LSJ PCM you do have a commanded Stoich which is ideal and the most accurate way to do this. They also have tables to put in the correct Injector data. Our PCMs don't. Our PCM's also have many other fuel and timing multipliers that we don't have access to either. With our Injector constant, its mostly a hack. With each different size/type of injector being out there, not having offset voltages/flow rate/dead times/ETC, There is no way to make it as good as it should be. With direct injection, the injectors have calibrations on them (which are programed to the PCM/been this way for years in the Diesel world) .I understand what you are trying to say as far as your conversions, but in reality with our PCM its just not SAFE to run E85 without the correct tables. Too many factors come into play, and people will be melting pistons.





P&P Tuning
420.5whp / 359.8wtq

This probably goes without saying, but your gonna need a lot more injector to get this to work. A bone stock eco is pretty much maxed out at 7k rpm with the stock injectors and a good tune. You'll need cobalt ss/sc injectors for a stock car.


This is of course, in addition to the concerns QWK is pointing out. I'm curious to see how the testing goes on your car. However like QWK said, strange/bad things can happen when you make a change to one parameter to make up for the lack of several others. How cold does it get where you live? LNF guys can adjust cranking advance to help light the high % alcohol for cold starts, but we cannot (at least not ecotecs). That is just one example off the top of my head.

Its gets cold here (will be snowing tomorrow and friday, have to drive friday in the snow with my summers on), and I have a few reasons why this wont be tested on this car. 1, I'll run out injector (65% idc's already, lowish fuel pressure for some reason). 2, If I advance my timing to take advantage of the e85 connecting rods could come out to say hello because honestly I could run 3 more degrees of timing than I do on 93 because I'm limiting power (because its cheaper than buying a bigger pulley, and I'm not too worried about melting the cast stock manifold). 3, I dont want to spend any more money on a fwd pos.

qwk ln2, it seems like what your saying is that no one should tune are pcm's are all for hardly anything because we dont have @!#$ for tables. Certainly no one should use the stock PCM for a turbo car, even the blower setup is a hack job. you either have to make do with what you got or dont bother.


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 wrote:Its gets cold here (will be snowing tomorrow and friday, have to drive friday in the snow with my summers on), and I have a few reasons why this wont be tested on this car. 1, I'll run out injector (65% idc's already, lowish fuel pressure for some reason). 2, If I advance my timing to take advantage of the e85 connecting rods could come out to say hello because honestly I could run 3 more degrees of timing than I do on 93 because I'm limiting power (because its cheaper than buying a bigger pulley, and I'm not too worried about melting the cast stock manifold). 3, I dont want to spend any more money on a fwd pos.

After reading this, I think you need to do some more research..... I don't see any reason why your rods would say "hello".....

Leafy wrote:qwk ln2, it seems like what your saying is that no one should tune are pcm's are all for hardly anything because we dont have @!#$ for tables. Certainly no one should use the stock PCM for a turbo car, even the blower setup is a hack job. you either have to make do with what you got or dont bother.

Can you please re-word this? I am having a hard time desiphering what you are trying to ask or say.....





P&P Tuning
420.5whp / 359.8wtq

QWK LN2 (P&P Tuning) wrote:
After reading this, I think you need to do some more research..... I don't see any reason why your rods would say "hello".....

I'm worried about making too much power with a 2.8" pulley on the mp62 with stock internals.

QWK LN2 (P&P Tuning) wrote: Can you please re-word this? I am having a hard time desiphering what you are trying to ask or say.....

What I was trying to say is. We dont really have the tables/ability to tune for boost either. And by your logic for why we cant run e85 we shouldnt be able to be turbo'ed either.


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

Your not gonna make too much power on the blower, you're gonna make too much heat But in all seriousness, if you are going to run a 2.8" pulley on an otherwise stock engine, e85 is the only way to go. At the blower speeds with that pulley, there is going to be a good struggle against hot air and knock.

So just so i understand, are you suggesting in this thread that someone else try this or that you intended to try it and reconsidered? I see you added the disclaimer up top, but i wanted to understand your original intentions. I read it as this is something that you are doing to your car, and was interested in seeing how it turned out in the end.

It was an idea I came up with, and I should have formatted it better but I wasnt in the right state of mind the other night. I wont be doing it but the idea and process are in the wild now so anyone with the proper inclination can use it.


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

I also just thought if this now, but I have no way to test it as I cant seem to find my hpt cable (I hope its in my dorm room in worcester, else someone broke into my car to steal just the cable and nothing else). Anyways, what needs to be tested is if the iat and ect spark correction tables do anything to cranking and cold startup spark advance. If they do then we have a way to tune those to compensate for e85 startup. Both tables go cold enough to where anyone turbo'ed or blown should never see the cells we'd be changing in boost, or even while normal driving.


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