giardinetta seconda generazione :)

[rverdoold]

I hate to disillusion you, but that engine makes less torque and power on LPG. Look closely at the graph. Power is torque x RPM, so if it makes less torque at a given RPM, it makes less power, too. The bumps in the LPG power graph are matched by the bumps in the lower torque graph.

During conversion, is anything done to optimize the engine operation for the higher octane rating of the fuel? Timing, manifold heating (more or less with liquid injection?) etc.?

 

No dissolution to me. I know I have less power on LPG. But the graph seems coloured incorrect to me then. I agree with you that it matches the HP curve.

I am very curious how much power my 1.6 has on LPG having to pull about 1300kg without me. While that outback with nearly a liter more of displacement weights about 200 kg more. I should have 70 KW and about 143 NM on gasoline so -10% is not so much left. It is not a racer and far from fast but ok it is cheap to drive.

 

I have no idea if it got retuned. There are 2 ECUs in the car; the original for the gasoline part and the LPG which communicates with the car-ecu. I thought LPG was octane rated at RON 108 or even somewhat higher. I know it really differs per season, winter LPG has more propane I get lower MPGs compared to cold autumn or spring, not much but noticeable.

The system is basically a tank with a pump pumping liquid LPG to the heat exchanger (connected to the inner circle of the engine heatings system). LPG is heated to about 60 degrees C and from there a single hose goes to the piezo injectors. These injectors wear somewhat faster compared to gasoline. About 120k KM but that depends on the driving style I think. The LPG ECU gets all sensor data from the normal ECU and manages knocking and spark timing as well as injection pulse length. I can monitor these values from the ecu with romraider.

Things I can not change but are possible are switching temperatures gasoline to lpg, power pressure (some systems can give double injection at full throttle or even combining gasoline and LPG parallel) but that is for racing cars.

Edited January 27, 2012 by rverdoold

[robm]

Yes, the colour coding on the graphs is wrong.

 

So is the LPG injected as a liquid under (very) high pressure or does the exchanger vapourize it?

 

Here in North America, we figure 20% less power on propane using vapourizers, as that is about how much air it displaces. In practice, it was often a bit better than this, only 10 -15% down, especially if timing is adjusted and manifold heating is eliminated. If the engine can have its compression ratio raised, it was theoretically possible to have the same power output, but I don't know of anyone who achieved this goal. This was the state of the art 20 years ago. Today's engines are probably more efficient on gasoline, and it may be hard to get this sort of combustion improvement on LPG.

 

70 kW*.9/746 = 84 HP from your 1.6 l engine. My Loyale is supposed to produce 90 HP. On a good day, 20 years ago. I think I could live with what you have.

Edited January 27, 2012 by robm

[rverdoold]

It should be still liquid (according to the specs) it is heated to prevent the injector from freezing. Because it chills at the moment it is injected. But it should be hot enough I would think so.

 

Sorry: The system I have in the 1.6 is vapourised (VSI). And the system my father had in the 2.5 outback (2005) was liquid injection (LPI) The car from the movie has most likely the liquid injection.

Edited January 27, 2012 by rverdoold
my mistake :D