Ideally you would get both done at the same time but you need the software to tune the LPG delivery running on the DYNO at the same time as the haltech tuning software to advance the ignition.

The Haltech can create 2 maps for watever you like. You can control both fuel delivery and spark on the petrol side i.e. maybe a sport map and a economy map. Or instead you could use the second map option just to advance spark for something else say LPG but the haltech won't control LPG delivery this is done by the LPG ECU.

The LPG ECU controls the delivery of LPG to the car. The spark timing is controlled by the car ECU and tweaked by the Haltech. Some LPG systems also control the spark timing and again the Haltech can be patched into those systems.

If you have an early P38 then there is NO oxygen sensor which makes it harder for the gas installer to tune as they use the oxygen sensor when setting up there gas map. Thus they tune it by feel In later models the LPG map is probably going to be a lot better because of the inputs from the oxygen sensor. The advantage of having the ignition and the gas tweaked together is you can adjust one against the other and see what difference this makes i.e fine tune. I know with mine while the KW increase was much the same for petrol and LPG, the LPG delivers power very different to the petrol map primarily because the LPG map wasn't optimised i.e. maximum power and torque are quite high in the rev range where as in the petrol map they are much lower and the overall map is much smoother for petrol.

The advantage Ron will have is a torque/power curve to show the LPG installer which might help them improve the lpg delivery but the back and forth tweaking that Ward does on the petrol side won't be possible on the LPG once Ron leaves the shop.

Either way Ron will have a HUGE smile as leaves the driveway for at least a couple of weeks until the thrill wears off