c5 flex fuel questions
09-26-2016, 07:06 PM
#22
yea, the 0411 and p59s are generally the same. I've used p59 unmodified harnesses and everything worked when i plugged in the 0411. Some of the pinout "grounds" and what not might be different, but if you follow the diagrams, it all ends up being the same crap. plug and play most of the time.
10-25-2016, 10:16 PM
#23
Yes it works in a c5 Vette. In fact, I found this first working on a c5 with an ls3. The owner wanted a DBC throttlebody but keep everything OEM, I stumbled upon the capability of the express van PCM having a "iac chip". More details on that here,
http://www.lt1swap.com/cable_conversion.htm
So I ended up converting the c5 to a DBC and noticed that the express van OS had 3 bar upgrade available AND it had a flex fuel option. After that, I implemented it in my fbody.
It's a shame people make this out to be some black magic deal and don't share the info. Keep in mind i pinned the PCM (added wires) to accompany the IAC motor, and TPS so for a total of 7 wires.
But yes, if you know what youre doing, itll work.
http://www.lt1swap.com/cable_conversion.htm
So I ended up converting the c5 to a DBC and noticed that the express van OS had 3 bar upgrade available AND it had a flex fuel option. After that, I implemented it in my fbody.
It's a shame people make this out to be some black magic deal and don't share the info. Keep in mind i pinned the PCM (added wires) to accompany the IAC motor, and TPS so for a total of 7 wires.
But yes, if you know what youre doing, itll work.
EDIT: I see that you provided the part numbers in the above link but are they 3bar equipped?
Last edited by Monte4ever; 10-25-2016 at 10:41 PM.
10-25-2016, 11:06 PM
#24
After reading more and understanding things better I see that you only have to add the wires if you are converting to DBC from DBW. Basically all that needs to be done if already using a 411 PCM and 4l80e trans is pinning for the flex fuel sensor and tuning the Express Van PCM. Thank you very much for this info. One more question, how would you know if you have a Express Van PCM with 3bar capability?
10-26-2016, 01:13 AM
#25
Just purchase a 04+ express van pcm with the following build numbers like on that link, thatll ensure that you can run a DBC throttle body first of all. Then youll scan the pcm without licensing it first and checking if it has an available 3 bar upgradable OS. If it doesnt, download one from the repository that dors have 3 bar capability then license that file and then license the file in the current pcm you purchased for a total of 200$ in credits if your computer didnt initally have a 3 bar upgradeable OS. Then flash your pcm with the 3bar upgradeable OS u found in the repository then pin the flex fuel to your pcm, and activate it in the file, and everything else is self explanatory TBH. I have unlimited creditd fot most if not all chevy v8 vehicles so i dont have to pay for the 200$ penalty in credits, making it a much more "economical" choice for me. And yes add the wires for the tps and the iacv unless you already have an 0411 then just swap computers.
10-29-2016, 07:04 AM
#27
Just purchase a 04+ express van pcm with the following build numbers like on that link, thatll ensure that you can run a DBC throttle body first of all. Then youll scan the pcm without licensing it first and checking if it has an available 3 bar upgradable OS. If it doesnt, download one from the repository that dors have 3 bar capability then license that file and then license the file in the current pcm you purchased for a total of 200$ in credits if your computer didnt initally have a 3 bar upgradeable OS. Then flash your pcm with the 3bar upgradeable OS u found in the repository then pin the flex fuel to your pcm, and activate it in the file, and everything else is self explanatory TBH. I have unlimited creditd fot most if not all chevy v8 vehicles so i dont have to pay for the 200$ penalty in credits, making it a much more "economical" choice for me. And yes add the wires for the tps and the iacv unless you already have an 0411 then just swap computers.
Last edited by Monte4ever; 10-29-2016 at 11:34 AM.
10-31-2016, 03:02 AM
#28
If you have to flash the PCM for the 3bar OS does it have to be "Write Entire"? Asking cause I never performed a mod like this before. Also, I've read that there is more that has to be done for this mod to work correctly excuse there are other tables that may need to be added. One example is getting the timing to automatically adjust upwards hen E85 is added to the system. On your setup is ALL the tables populated and functioning correctly? One of the main reasons for me to use E85 is to be able to add timing automatically.
and yes, timing is adjusted "automatically" the way I am talking to you about, thats the whole purpose behind the flex fuel os and the sensor. Once you setup the tables accordingly, the flex fuel sensor will tell the pcm how much ethanol content the fuel has, and will adjust the fuel, and ignition timing based on your table values, or whatever preferences you end up going with. FOR EX.
you set up the tables to add 5 degrees everywhere in the HO table once the flex fuel sensor spits out anything higher than 70% ethanol. or you can blend the set up so that it adds 7 degrees when it sees 100% ethanol, 5 degrees for when it sees 70% ethanol, 3 degrees for when it sees 50% ethanol, and no timing added below 50%. THIS IS PURELY AN EXAMPLE, YOU CAN TAILOR THE TABLES TO WHATEVER YOU WANT AND IT'LL DO SO "AUTOMATICALLY".
10-31-2016, 09:56 PM
#30
yes you have to perform a "write entire" to change the OS. and populating the flex fuel tables, that is something your tuner will have to do hence why i never mentioned it. If you are going to the tuning, i will post here exactly what tables you need to populate with exactly what values.
and yes, timing is adjusted "automatically" the way I am talking to you about, thats the whole purpose behind the flex fuel os and the sensor. Once you setup the tables accordingly, the flex fuel sensor will tell the pcm how much ethanol content the fuel has, and will adjust the fuel, and ignition timing based on your table values, or whatever preferences you end up going with. FOR EX.
you set up the tables to add 5 degrees everywhere in the HO table once the flex fuel sensor spits out anything higher than 70% ethanol. or you can blend the set up so that it adds 7 degrees when it sees 100% ethanol, 5 degrees for when it sees 70% ethanol, 3 degrees for when it sees 50% ethanol, and no timing added below 50%. THIS IS PURELY AN EXAMPLE, YOU CAN TAILOR THE TABLES TO WHATEVER YOU WANT AND IT'LL DO SO "AUTOMATICALLY".
and yes, timing is adjusted "automatically" the way I am talking to you about, thats the whole purpose behind the flex fuel os and the sensor. Once you setup the tables accordingly, the flex fuel sensor will tell the pcm how much ethanol content the fuel has, and will adjust the fuel, and ignition timing based on your table values, or whatever preferences you end up going with. FOR EX.
you set up the tables to add 5 degrees everywhere in the HO table once the flex fuel sensor spits out anything higher than 70% ethanol. or you can blend the set up so that it adds 7 degrees when it sees 100% ethanol, 5 degrees for when it sees 70% ethanol, 3 degrees for when it sees 50% ethanol, and no timing added below 50%. THIS IS PURELY AN EXAMPLE, YOU CAN TAILOR THE TABLES TO WHATEVER YOU WANT AND IT'LL DO SO "AUTOMATICALLY".
Last edited by Monte4ever; 10-31-2016 at 10:03 PM.
10-31-2016, 11:05 PM
#31
you read it, the tune comes up and you decline to license it. you cannot save any changes to it, but you can copy and paste from it to a licensed tune.
got my PCM today. flashed in the '04 express van OS. changed to 3 bar ---no RTT available for this OS
--- and glanced around the fueling tables. looks like some fun.
Just need to hunt down a sensor, plumb and wire it and find some alky
got my PCM today. flashed in the '04 express van OS. changed to 3 bar ---no RTT available for this OS
--- and glanced around the fueling tables. looks like some fun. Just need to hunt down a sensor, plumb and wire it and find some alky
11-01-2016, 05:38 PM
#35
the first picture shows what stoich the pcm will command based on the top column which is %ethanol. so 100% ethanol=8.77 AFR
The second picture gives you the blend factor and the OL fueling for alcohol.
The blend factor is the most important here.
The blend factor will signify how much "weight" the flex fuel tables will have. You can see in the picture the 80% composition gives you a full 1 point.
This signifies that for instance, if you have 80% ethanol, it will blend 100% of the open loop fuel table, or simply put, it will reference 100% of the alcohol open loop table. If the ethanol content was say, 50% it would blend 62.5% of the alcohol table, or in other words itll weight 62.5 % of the value in the alcohol table and 37.5% of the weight will be that of the gas table.
Simply put, if we put on the flex fuel spark table a value of 10 all across (table on the 3rd image, note: this table doesnt have 10s everywhere, it was just referenced from a stock ff calibration), if we have 80% ethanol or higher, the blend factor will give a multiplier of 1 (100%) of the value in the spark table, which is 10. So 1*10=10 , 10 degrees of additional timing.
If we have 50% ethanol, the multiplier is 62.5% or .625*10=6.25 degrees of added timing whenever you have 62.5% ethanol or e62.
I can make a video later this week if you still dont got it, just a little busy ATM with petroleum exams
The second picture gives you the blend factor and the OL fueling for alcohol.
The blend factor is the most important here.
The blend factor will signify how much "weight" the flex fuel tables will have. You can see in the picture the 80% composition gives you a full 1 point.
This signifies that for instance, if you have 80% ethanol, it will blend 100% of the open loop fuel table, or simply put, it will reference 100% of the alcohol open loop table. If the ethanol content was say, 50% it would blend 62.5% of the alcohol table, or in other words itll weight 62.5 % of the value in the alcohol table and 37.5% of the weight will be that of the gas table.
Simply put, if we put on the flex fuel spark table a value of 10 all across (table on the 3rd image, note: this table doesnt have 10s everywhere, it was just referenced from a stock ff calibration), if we have 80% ethanol or higher, the blend factor will give a multiplier of 1 (100%) of the value in the spark table, which is 10. So 1*10=10 , 10 degrees of additional timing.
If we have 50% ethanol, the multiplier is 62.5% or .625*10=6.25 degrees of added timing whenever you have 62.5% ethanol or e62.
I can make a video later this week if you still dont got it, just a little busy ATM with petroleum exams
11-01-2016, 07:22 PM
#36
GREAT info Subeone. This helps a lot. Now I gotta sit down and go over it a hundred or so times lol. Question, the Blend Factor table blends both the OL Flex Fuel table and the Flex Fuel spark table? Also, I understand that the flex fuel sensor signal wire goes to p56 blue. What pin does the ground and power wires go to?
Last edited by Monte4ever; 11-01-2016 at 10:17 PM.
11-01-2016, 11:36 PM
#37
no problem, and yea the blend factor is for both the ol fuel table and the flex fuel spark table. Some newer OS's i think have a separate blend factor for the flex fuel spark table alone, dont quote me on that. I know e38s do for sure, not sure on p59s.
the ground just goes to any chassis ground, and the power goes to any key switched power. neither have to go to a pin, except for the signal wire which goes to 56 on blue connector.
EDIT: forgot to mention that in the 2nd image, at the far right you can see the flex fuel "enabled" drawdown box. Make sure that is enabled in your file and the the default percentage is 38%. Make those changes in yours, as it will be disabled in yours, make sure to click the drop down box and select enabled.
the ground just goes to any chassis ground, and the power goes to any key switched power. neither have to go to a pin, except for the signal wire which goes to 56 on blue connector.
EDIT: forgot to mention that in the 2nd image, at the far right you can see the flex fuel "enabled" drawdown box. Make sure that is enabled in your file and the the default percentage is 38%. Make those changes in yours, as it will be disabled in yours, make sure to click the drop down box and select enabled.
Last edited by subeone; 11-02-2016 at 03:33 AM.
