AFR with LPG ?!?!?!?

[csimoes]

hi

after some reading about tuning with MS i have a few questions that maybe
you can help me out.

my RR 3.9 runs on LPG 99.9% of the time, only use gas to start and warm up till 45º then
it switchs to LPG.

all the AFR tables i've seen are based on stroich of gas 14.7 but if LPG is 15.5
shouldn't there be a table based on LPG 15.5??

if gas AFR is 12.5(power) - 14.7(effyciency) - 16.1 (economy) (more or less)
a simple translation to LPG (if that's possible..) is

13.3 (power) - 15.5 - 17.1 (+-)

if using the gas AFR with LPG, won't it allways be richer than it should?

or i should just forget about this because LPG is less efficient than gas and thus running rich
will compensate for it?

cheers

Carlos

[elbekko]

Won't that only matter if you have a wideband lambda?

If you use a normal lambda sensor, it'll just see the result of the combustion, and tune for that.

[Quagmire]

From what I have read lambda is lambda whatever fuel you use, AFR is just a numerical conversion of that lambda value to give you something more meaningful to work with. You can therefore just tune using petrol afrs as if you were running on petrol. This saves reconfiguring anything or any confusion with fuel ratios

[Bowie69]

Yup as above, it will tune to the correct mix of whatever fuel you run, assuming it's not too wildly out.

[csimoes]

Ok less work then

Thanks