lambda

I am enjoying this course. I do not intend to be a Dyno tune specialist but i am very interested in get the best performance from my circuit race car. . I would like to understand what device measures Air Fuel ratio and Lambda measurement? Is it the same sensor? how does this work?

thanks Keith

Hi Keith,

A Oxygen sensor measures the remaining oxygen concentration in the engines combustion gases, this is then converted by the controller for the sensor into a Lambda (or stoichiometric) value. This value can then be further converted into an AFR based on the fuel that is in use. Lambda is the preferred value to use as it doesn't have the further requirement of translation based on the fuel used.

For example, Lambda 1 in Petrol is 14:1, E85 is 9.85, E100 is 9.