LPG economy tuning

[oztracktuning]

I am about to do some basic changes of the calibration on a LS1 Statesman that runs on LPG. The owner just wants improved fuel economy.

Any concepts different than a Petrol car.

I am anaware of what type of system its running at this stage.

Will my wideband a PLX M300 work with LPG and what are the desired afrs??

[TAQuickness]

You will need to know the stoich ratio for LPG. Might be able to find it in the B3601 or google. You may also want to do a little research on the LPG to become a little more familiar with it's properties.

Bringing on DFCO a little sooner, and leaning out the cruise area should improve the fuel economy.

[oztracktuning]

Have been researching.
Stoich is 15.5
But the M300 will just say 14.63 same as usual.

I wonder how they like timing compared to petrol. Higher octane i guess it may like more than usual.

[TAQuickness]

I would have thought the M300 would allow you to switch fuel types. Not sure if you will be able to use it if you can't set lamda. Or if you do use it, how it will effect the tune.

[oztracktuning]

Apparently it doesnt matter. 14.63 represents Lamda 1.0 so in truth 15.5 (stoich) for LPG will be displayed as 14.63 on the M300

[Highlander]

Try to maximize timing... tune for best power and/or throttle response regarding to timing and you will always get best fuel economy.

[Rico]

How did you make out?

10 deg at idle, then lots after?

Propane likes compression so I who think you could use lots of advance under power. I run an old HIE ignition on another truck. The low idle timing helps keep it smooth at idle.