Can somebody explain Lambda to me....
AudiWorld Senior Member
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I'll bite
From the Haynes FI Techbook:
Lambda: The greek symbol used by engineers to describe a ratio of one number to another. Expresses the air-fuel ratio in terms of the stoichiometric ratio compared to the oxygen content of the exhaust. At the stoichiomnetic ratio, when all of the fuel is burned with all of the air in the combustion chamber, the oxygen content of the exhaust is said to be at lambda=1.0. If there is excess oxygen (lean condition) then lambda > 1.0; if there is an excess of fuel in the exhaust ( a shortage of oxygen is read by the sensor) then Lambda is less than 1.0
Does that help?
Lambda: The greek symbol used by engineers to describe a ratio of one number to another. Expresses the air-fuel ratio in terms of the stoichiometric ratio compared to the oxygen content of the exhaust. At the stoichiomnetic ratio, when all of the fuel is burned with all of the air in the combustion chamber, the oxygen content of the exhaust is said to be at lambda=1.0. If there is excess oxygen (lean condition) then lambda > 1.0; if there is an excess of fuel in the exhaust ( a shortage of oxygen is read by the sensor) then Lambda is less than 1.0
Does that help?
Junior Member
Joined: Mar 2000
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YA
I assume you mean Lambda as it represents 14.7:1 air/fuel ratio? Actually, it depends.. If you want maximum power, you want Lambda to roughly = 12.5:1. Best emmissions is around 14.7:1 which is also called Stochiometric (probably spelled wrong.. I'm kinda drunk at the moment). Basically if you modify your car and measure the O2 level, you can then tune so that the approximate value is between 14:1 parts air to 1 part fuel and 12 parts air to 1 part fuel. For a stock car, this will do basically nothing for you..
Dave.
Dave.
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Joined: Mar 2000
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Uhhm not quite, but concept is true. Lambda = 1 = stoichiometric = 14.72:1 air-fuel mass ratio =
O2 sensor cycling back and forth from 0.4 to 0.6 V in close loop operation. The O2 sensor is sometimes refered to as lambda sensor because it generates a higher value of lambda with increased values of O2 in the exhaust stream and vice versa. So to put in perspective, A lambda of 0.8 represents about 12:1 ratio, A 1.2 lambda is about 17:1. Now my question is, how do I enter that symbol in here (upsidedown y) :P
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