AEM 30-6905 Universal Programmable EMS-4 User Manual
Page 124
Page 124 of 279 EMS-4 Install and Tuning Guide_Rev 1.6
Turbocharged Piston Engines W/ Pent roof Combustion Chamber
Air/Fuel Ratio
L
300
13.0:1
12.5:1
12.2:1
12.2:1
12.2:1
12.2:1
12.2:1
12.2:1
O
275
13.0:1
12.8:1
12.5:1
12.5:1
12.2:1
12.2:1
12.2:1
12.2:1
A
250
13.0:1
12.8:1
12.5:1
12.5:1
12.2:1
12.2:1
12.2:1
12.2:1
D
225
13.0:1
12.8:1
12.8:1
12.8:1
12.5:1
12.5:1
12.5:1
12.5:1
200
13.0:1
12.8:1
12.8:1
12.8:1
12.5:1
12.5:1
12.5:1
12.5:1
I
175
13.0:1
13.0:1
13.0:1
12.8:1
12.8:1
12.8:1
12.8:1
12.8:1
N
150
13.0:1
13.0:1
13.0:1
13.0:1
13.0:1
13.0:1
12.8:1
12.8:1
125
13.0:1
13.0:1
13.0:1
13.0:1
13.0:1
13.0:1
12.8:1
12.8:1
K
100
13.0:1
13.0:1
13.0:1
13.0:1
13.0:1
13.0:1
12.8:1
12.8:1
P
75
14.0:1
14.2:1
14.2:1
14.2:1
14.2:1
14.2:1
14.2:1
14.2:1
A
50
14.0:1
14.7:1
14.7:1
14.7:1
14.7:1
14.7:1
14.7:1
14.7:1
25
14.0:1
14.7:1
14.7:1
14.7:1
14.7:1
14.7:1
14.7:1
14.7:1
Idle
Maximum
RPM
The AFR is often referred to as a Lambda (
) number. A Lambda of 1.00 is equal to the
stoichiometric ratio for the reactants in a system. For our purposes, the stoichiometric ratio is
the ratio for the amount of ANY fuel used in an internal combustion engine. With Lambda
measurement, any number higher than 1.00 is considered lean (more air than necessary to
react with the fuel) and any number lower than 1.00 is considered rich.
Although Lambda is the term most often used when working with O2 sensors, we will use AFR
in this manual because it is the most common term used when referring to internal combustion
engines. The following is a chart for converting Lambda values to AFRs.