Lambda value/ AFR correlation

[Brad Sheridan]

>I am also curious about this question. I have an Autronic SMC computer
>driving my race car. when i log the A/F ratio and convert it to lambda at
>14.7 it shows lean numbers of .87 , i adjust so the readiout is .9 but car
>goes slower
>i guess af->lambda is not linear
>
>doug

 I'm not familiar with the Autronic, but if its using a standard O2 sensor,
that is probably why the AF->lambda may not appear linear. The O2 sensor
won't give you an accurate AFR, which would result in an inaccurate lambda
value. The relationship between AFR and lambda should be linear, the
relationship being
(1/stoichAFR) * measuredAFR = lambda, as Frank stated.

  This leads to another question. Is the stoich AFR something that varies
according to location? An archived post refered to 14.57:1 being an
Australian
stoich number. If it does vary, how much? I'm curious as to whether or not I'd
see noticable variance across the US at ground level (sea level to approx 1
mile above).

Thanks,
Brad