Fuel Curves

[xxalexx at ix.netcom.com]

Fuel vs airflow is a bathtub curve for non emission cars.
You want smooth idle, good fuel economy and high power.
Thus A/F is rich, lean, rich 
alex
> 
> What would an ideal plot of manifold vacuum versus injected fuel
> quantity look like? I am still on the job of tuning my Lucas mechanical
> injection - last night I measured the fuel curve and it seems a bit dodgy to
> me (although my opinion is not very qualified). At low vac the fuel
> delivery is high, and it drops very rapidly (and linearly) until it reaches
> about one third of its original quantity, and then it changes slope and
> linearly decreases until it gets to max vac. This means that about the first
> 10% of the total vac increase reduces the fuel quantity by about 66%
> and the last 90% of vac reduces it by 33% (the two parts of the graph
> are both linear of course because it relies on springs to derive the
> curve). Does this seem good/bad/otherwise to anybody who knows?
>