Originally Posted By Mark Whitener
With an Innovate or some others that's correct, however if his O2 system is set for typical gas stoich at 14.7 your table has no value. Sensor calibration is done in free air, however the gauge calibrations if set and unchangeable at 14.7 (equaling a 1.0 Lambda) will suggest a starting point reading around 12.2 to 12.5, which translates to .83 to .85 Lambda. Those are safe starting numbers, jet from there as needed for best performance.


I agree the 12.2 can be used as a starting point, but with E50 it will be lean, and even more so with 12.5.

As far as I can see the table I published is correct:
- Stoich for E100 = 9.0
- Stoich for pure gasoline (E0) is 14.7

With a 50% mix (E50) the stoich (Lambda=1) will be (14.7-0.5(14.7-9)=11.85, shown as 11.9 in the table.

For max performance with E50 we aim at Lambda = 0.85, which gives us roughly AFR = 10.1 with E50, shown as 10.2 in the table (Lambda target unknown for WOT in the table).

So in my opinion the table is correct, and an AFR gauge set to stoich 14.7 for pure gasoline, should display AFR = 10.1 for max power at WOT with an E50 mix. For ideal combustion (Lambda = 1) it should show AFR = 11.9


Martin, 67 Charger, 512 cui, E85, MegaSquirt MS3X sequential ignition & injection