Roland@pcmtec Posted November 21, 2023 Share Posted November 21, 2023 For those of you utilising our canbus or user flex fuel configuration. It appears you can use a hybrid of our custom logic and the Ford OEM logic. NOTE: This is yet to be tested by PCMTEC, however if it works it means you could use the OEM flex logic with our canbus/user flex fuel as the input to the ethanol content. This would mean no learning is required and you set and forget the ethanol content. You must also leave auF35397 "Calibration for Flag for Flex fuel system" disabled. Otherwise it would fight with our custom logic and cause weird things to happen. The FMT Custom OS Wizard will warn you if this flag is left enabled. First step is to calibrate auF29291 which is an AFR to PM % lookup. This will then cause PM percentage methanol (really ethanol but Ford like to call it Methanol) From a datalog this shows even with FFV (OEM flex fuel logic) disabled it still calculates the PM ratio. Note in an F150 where this table is calibrated they use values of 0-1 where 1.0 is 100% ethanol, therefore we would expect the the Mustang should work the same way. If you do not calibrate any of the other tables however, putting 9:100 in the first row may work, but your ethanol % will be completely wrong likely clipped at 1.0 (100% ethanol) From my brief reading of the code it appears that this means tables like the following could be used. auF31238 Load Limit for ethanol (eg if you didn't have sufficient fuel supply for E85 at WOT). This table does not appear to exist in the F150s, but it does exist in the Mustangs interestingly. Torque multiplier This is not tested however I am very confident that even the FFV tables for spark multipliers will be used. 1 Quote Link to comment Share on other sites More sharing options...
mejohn50 Posted November 21, 2023 Share Posted November 21, 2023 Going to try giving this a brief test this weekend. Will report back what I find. Quote Link to comment Share on other sites More sharing options...
junits15 Posted January 27 Share Posted January 27 I was actually able to give this a try. The file is attached if anyone is interested, unfortunately I wasn't able to get it to behave correctly. If I calibrated AuF29291 as you guys did, the ford ethanol percentage would track with the CuOS ethanol percentage measured off the sensor. However the car would idle at .7 lambda, absurdly rich it was targeting 9:1 AFR it seems. Barely started. I then assumed the table was swapped and tried the following: This allowed the car to idle at 1 lambda again, but the two ethanol percentages no longer matched. I tried various combinations but found that unless the top percentage was mapped to 0% the mixture would be off at idle. I also tried using .1 and .85 instead of 10 and 85 but found no change with that. Heres a picture of the car idling on e10 gasoline at 9.7:1 AFR lol. This is a real 9.8:1 because the lambda reading in the datalogger was .7. I also tried swapping all of the flex tables including the can flex tables. I know you guys said it works so I assume I dont have it set up quite right. Either way I wanted to report my findings, I figure the more data you have on this the better! Quote Link to comment Share on other sites More sharing options...
Roland@pcmtec Posted January 27 Author Share Posted January 27 It definitely sets the correct AFR and Lambda in our test car but we never did a full calibration hence the "this is yet to be tested" note. Now your table is upside down. That definitely won't work due to how the table lookup routines work. Have a look at an F150 file for an example of what values they use. Now once you get the AFR/stoich correct there is still probably 60 tables that need calibrating. Using the PCMTEC method is much simpler and what all our tuners use. Though if you have time it's worth persisting with this. Quote Link to comment Share on other sites More sharing options...
junits15 Posted January 27 Share Posted January 27 11 hours ago, Roland@pcmtec said: It definitely sets the correct AFR and Lambda in our test car but we never did a full calibration hence the "this is yet to be tested" note. Now your table is upside down. That definitely won't work due to how the table lookup routines work. Have a look at an F150 file for an example of what values they use. Now once you get the AFR/stoich correct there is still probably 60 tables that need calibrating. Using the PCMTEC method is much simpler and what all our tuners use. Though if you have time it's worth persisting with this. I've got nothing but time right now There are 73 tables to be precise, I made this handy little spreadsheet for anyone who wants to do something similar: F150 Flex tables, ECM to AuF.xlsx Green highlights are what I felt were critical tables. I think I'll start from scratch, something is missing from my tune. Which I also forgot to attach: 05_CustomOS_flex_basic_CustomOS.tec If you guys have seen it work then I definitely want to see if I can replicate it. Quote Link to comment Share on other sites More sharing options...
junits15 Posted January 28 Share Posted January 28 (edited) I was able to get it to function, I checked out the F150 tune and saw that the table was defined as shown below: It looks like it cannot handle values over 1. This explains my issue before, because I believe my table that caused rich running (shown below) was setting the internal value to 10, which the computer interpreted as 10000% and slammed the mixture to the maximum of 9:1 and caused the rich running. Edited January 28 by junits15 1 Quote Link to comment Share on other sites More sharing options...
junits15 Posted January 28 Share Posted January 28 (edited) Its seeming like its going to work, which is exciting. I'll be testing further Edited January 28 by junits15 1 Quote Link to comment Share on other sites More sharing options...
Roland@pcmtec Posted January 29 Author Share Posted January 29 This is interesting. As we never calibrated any of the other tables it set flex alc % to 38.65 in our datalogger when it likely should have been 0.3865 had the other tables been fully calibrated. Thank you for reporting back and we will update/clarify the original post that this is actually most likely a ratio and not % 1 Quote Link to comment Share on other sites More sharing options...
Roland@pcmtec Posted January 29 Author Share Posted January 29 Confirm it is indeed a unitless ratio, not %. I will get the templates updated to reflect this. 1 Quote Link to comment Share on other sites More sharing options...
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