Here's a chart to help explain the Stoichiometric A/F ratios and maximum power points for different fuels. Stoichiometric is the theoretically ideal air-to-fuel ratio, or as a scientist would call it, Lambda 1.0. Lambda 1.0 is the air/fuel ratio for engines that are running well under low to moderate loads, such as when cruising. But for maximum power, you have to be on the rich side of Stoich, usually 80 to 85 percent. The A/F fuel ratio for a normally aspirated Methanol engine under full load is around 5.4:1. Maxed-out blown alcohol engines often run all the way down to 4:1. We will use EGT sensors on the dyno to help decide what A/F ratio will be best for this engine, but our initial target will be 5:1.
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