pKa explanation

[AVP]

When i look at the maps and i see the pKa column i feel a bit dazzled when i try to apply that to the boost/vaccum figures i  see on the gauge.

I understand that 200pKa = 1bar absolute(gauge reading)

Can someone please give me the pKa readings for vaccum though?

on the map i have 30,46,56,80pka and i want to know how that resembles the vaccum readings i get when on idle/cruise so that i can deal with idle VE table settings as well as fueling under cruising speeds.

thanks
vasilis

[gunni]

1bar = 14.7psi = 100Kpa ~ 1013mbar

Kpa´s are ratios basically of 1bar.
50Kpa is half a bar and so on.

[AVP]

i realise that half a bar is 50pKa BUT what happens with vaccum which in gauge terms is -0.5bar etc?

Is it : 20pKa=100-80, therefore -0.8bar(in gauge terms)?

i think something like that was sort of an explanation in wiki.

otherwise,how is the map table done on vaccum conditions?

it should be something like:
pKa vs  vacuum
30   =   -0.7 
46   =   -0.64
56   =   -0.46
80   =   -0.2
100  =   0

[GintsK]

1bar = 14.7psi = 100Kpa ~ 1013mbar

Kpa´s are ratios basically of 1bar.
50Kpa is half a bar and so on.

Just to be precise: 1bar = 14.50...psi = 100Kpa= 1000mbar

[gunni]

i realise that half a bar is 50pKa BUT what happens with vaccum which in gauge terms is -0.5bar etc?

Is it : 20pKa=100-80, therefore -0.8bar(in gauge terms)?

i think something like that was sort of an explanation in wiki.

otherwise,how is the map table done on vaccum conditions?

it should be something like:
pKa vs  vacuum
30   =   -0.7 
46   =   -0.64
56   =   -0.46
80   =   -0.2
100  =   0

100kpa is 0kpa gauge pressure.
So 50kpa is 0.5bar vacuum
And the tables are based on absolute pressure.