What is the afr for a E50 blend of fuel? I would like to use this blend in my engine.
The AFR for E50 is 11.9. Max power would be AFR 10.2
I agree it's easier to use Lambda, but for initial settings you may need the AFR for calculations.
Here is complete info for you:
You can't use those numbers unless the AFR gauge is calibrated for the stoich of the fuel. In other words a gas scaled AFR gauge is calibrated for 14.7 as stoich for the fuel. The easiest way to use a gas gauge is to divide the observed number on the gauge by 14.7, that will give you the Lambda number. On a gas scale shoot for 12.2-12.5 as a starting point, jet for best performance from there.
The Lambda sensor measures the contents of the exhaust gases and when the combustion is optimal all oxygen is used in the combustion process. This is Lambda=1. Then for those people who want to use the old AFR value, you have to program in the stoiciometric value for your type of fuel. Based on the Lambda value measured, the AFR value is then computed based on the stoiciometric value programmed, and displayed if so chosen.
A Lambda sensor (AFR gauge) is calibrated in free air, not with any relation to the fuel type used.
