Dual Fuel Liquid LPG systems

[TOL]

Thanks Darren.

When do you think the M190 will be available?

You mention a guy with a 4-cyl M800 dual fuel deal. Was he switching back & forth between fuel A & B, or was he blending A+B?

If the M190 isn't going to be available for awhile, and if I decide I really want to "blend" as opposed to just switching between fuels, can you picture a way of doing so with my M800 in a V8 application? Maybe add a second M800 and have the two talk to each other somehow?

[DarrenR]

We don't have a release date for the M1 yet, officially it should be released already but that's what happens when you design and build a world class top end ecu from scratch... We are tentatively looking at the end of the year for release.

I don't have the full details on the system running dual fuel, but it was defiantly blending using hi/lo injection.

You can do it with an m800 (as i have said previously) in pairs of injectors, but if you really want full sequential hi/lo injection, yes you can use 2 m800s linked together. They run as two 4 cylinders so 4 low and 4 high injectors and 4 coils on each ecu. It is a fairly involved setup, but once done they talk to each other on CAN and you only need to tune one ecu.

[SportsCarRacer]

Cool! As i thought!
That's the easy bit solved for this installation with liquid!

302man, what LPGi system hardware are you proposing? Vialle (Boral), Motonic, etc? This has a big bearing on the sucess of the system you propose. The extra ECU is not just a "piggyback", it has extra sesnor inputs for rail pressure, & temperature, lockoff control, and most importantly, pump speed control to control delivery volume & the prime regime for easy starts at all temperaures. You see, liquid LPG always wants to vaporise into a gas, so you run the car, you stop, and the liquid in the rail bolis to vapor...when you return, the system must purge the vapor from the rail to ensure a start. Right now, this is very difficult to execute elegantly in an M800 (it was never designed to do this!), but it could be done with some extra electronics that processed this off-ECU, and sent back signal to the ECU...however, i could easily write an algorithm to do it and much more in M1! (but not until they are released!).

The pump requires speed control via scaled PWM signal to the pump motor controller, ususally continually switching between 5 discrete states.
Injectors are same drive regime as gasoline ones, they are low impedence peak & hold.
IMPORTANT: it will be very difficult to get the injector bat voltage & pressure compensations measure by MOTEC by the nature of LPG vaporising! It would need to be calculated empirically from the slope & offset data from the injector manufaxcturer (not always easy to get!)...failure to do this basic step will result in a substandard system, that will never be right!! Usually curve programmed into piggyback ECU by system manufacturer....
The above is a gross over-simplification...but LPGi (liquid) is quite involved cal wise and knowing the rail temp & pressure and making the appropriate corrections to ensure consistency at any temp and gas mix.....

You could more easily implement the dual fuel system you require with a VAPOR injection system (eg: PRINS)....i'm involved with one on a 400 cleveland in an F-truck tow car. hardware much cheaper too!

Why do you specifically want LPG liquid injection?

[Blu302]

I was looking at the liquid system because of the milage benefit over gas systems and that there is no degradation in power output. The brand i was looking at was lpg liquid inject Ltd, new mob here in Aus that has just managed to get past the government red tape this year and is less than half the price because it is local(Melbourne i think).