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Old 09-14-2016, 03:11 PM   #21
TSloper

 
Drives: 2016 Camaro SS
Join Date: Jan 2016
Location: Mount Dora, FL
Posts: 779
Quote:
Originally Posted by 97ChameleonTA View Post
Just a thought, not sure tuning to true 85% is a good idea unless you plan on using the E98 to keep it there all the time. On my ZL1 I have my DashLogic setup to show E%. It usually hovers right at 70 - 72% with pump E85. Also, in talking to Dave Steck some time ago, it seems there is little to gain above 70%.
The way the interpolation works on the ECM is that there is a timing adder table for Flex Fuel. At low RPM/load it is primarily taking away timing. At higher RPM/load it is adding timing. It will give you a percentage of the cell value based on the E %.

So on our ECM it is...

E0 -> 0.00
E10 -> 0.00
E20 -> 0.20
E50 -> 0.50
E80 -> 1.00

So for E70 it will be about a 0.83 multipler. I'll tune for the E70. If I end up with something closer to true E85 in the tank it won't be a significant delta on the timing adder.

Tim
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