I have a guys 2010 Camaro that's decided to add a flex fuel sensor. What do I need to change in the tune to support that and tune using the flex fuel sensor? Never really done a flex fuel conversion, just E85 cars normally. Not really sure what I should change or look out for.
Thanks
So this got put on the back burner but revisiting.
Looks like under Engine, Open & Closed loop, flex fuel sensor. Change from disabled to enabled.
Engine, fuel, General, stoich AFR table needs to be adjusted so that 0.0% is 14.67 and 100% is 8.97. Essentially how it was sock.
Engine, spark, advance, Flex Fuel Spark. This table is all 0. Do I populate with how much spark it adds to base spark? or what actual spark values I want?
Engine, spark, advance, Mult vs. Composition. This has 5 cells of "interpolation factor" vs % 0 to 100. Cells are all 0 by default but need to be populated. Any ideas with what? It appears to be related to the Flex Fuel Spark table listed above. How much to use it.
I think those are the main items to address.
Thanks
Does anyone know of factory flex fuel cars that used the same ECU as this 2010 camaro? I see the tune repo is back up and I could possibly figure it out that way.
Flex fuel trucks get you real close for the stoic table and the multipliers. Flex fuel spark is an adder to the main spark tables. The stock truck flex fuel spark table is way out in left field. I zero it out and then add where I need for power. Usually in the upper half of the airmass.
Thanks I tried a 2010 Silverado truck and found the settings for the Mult vs. Composition. The Flex Fuel Spark I will use to add spark into E85 for power just like you did. That's how I was hoping it worked. Seems easy enough.
I noticed under:
Engine, Fuel, Flex Fuel, Maximum Ethanol Percentage: 80%
Is that set that way because that's the limits of the GM flex fuel sensor? or set there so ethanol content over 80% is ignored? Seems like A/F would go off from E80 to E85 if it's capped there. I know our local pumps have anywhere from E70 to E90 depending where you fill up. Most commonly around E85 ~ E86.
ive had mine with over 89% reading in there and the setting was still on max 80% so im not sure what it actually does but i have changed it to 100% now
Interesting. I'm noticing this car is reading around 77 ~ 78% (almost 80%) and it's giving the full amount of timing I put on the "Engine, spark, advance, Alcohol" table I think it is. I wonder since you changed yours to 100% if now it'll ratio out to a 100 and at 80% ethanol only give 80% of the additional spark for ethanol?Originally Posted by 07GTS
think it should be ok had a look thru and the multipliers have 1 for 80% or 100% so should be the full change of timing and fuel
The 80% max for the flex fuel is so that it matches the flex fuel multiplier table. The last multiplier comes on at 80%, I think both of those need to match otherwise you wont get the last multiplier table.
Makes sense, thanks.
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