Looks like my Flex Fuel Tundra is pulling timing for E85, is this how all of them are tuned?
I would have thought it would be the other way around as E85 is higher octane. It also only adjusts to a max of 75% alcohol.
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Looks like my Flex Fuel Tundra is pulling timing for E85, is this how all of them are tuned?
I would have thought it would be the other way around as E85 is higher octane. It also only adjusts to a max of 75% alcohol.
Attachment 90898
Also wanted to ask about timing tables in the base section. I know in GM when tuning you would copy the high octane spark values and paste them into the low octane spark values. Anyone know if this is the same for Toyota? Would I copy the high octane values and paste them into the low as well as the base spark table to ensure optimal timing in all situations except for when knock is detected? When I hover my curser over the base spark button it states "[ECM] 42223 - Base Spark vs. RPM vs. Load: The lowest of this table and the High Octane, Low Octane, knock learn adapt combination is used." wouldn't this mean that if I don't input the high octane values into all 3 sections that it will use the lower of all? It may not require this because it states it uses a combination but wanted to clarify.
Thanks in advance
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Post a log with as many parameters as possible.
Ok thanks, would you recommend bumping them all up by the same percentage at all or just the high octane and base, or high octane only?
Any input on the flex fuel values? I'm assuming just treat it as you would gasoline and increase timing until loss of power or knock is detected, I see much potential gains being possible there with the higher octane of E85. And aim for a AFR of 7-8 if the widebands are capable of readouts of that fuel as I only see a stoich AFR in the Fuel section of 14.6 with no AFR section or adjustment based on Alcohol content, just fueling variations.
Toyota's E85 code calculates an additional fuel multiplier (like a fuel trim) based on the calculated alcohol % instead of adjusting the stoich value as GM would (although it has the same effect). I've being working to add some more stuff there but like most Toyota stuff it seems non-intuitive. The knock control is another area that has design principles that escape me...
Thank you both very much for the info, I look forward to any and all updates you guys have going forward.
Toyota's mapping strategy is not very intuitive as Chris pointed out. There's a lot more going on with the timing maps than meets the eye. But in short, my advise for dialing in your timing would be to first adjust each cell equally in each map (HO, LO, Base). Add one degree to base, add a degree to LO/HO in that same cell.
As far as flex fuel values, I do not have enough experience with the platform and E85 to offer you any solid advice there.