Those who run LPG converted 2.2's

[kibby]

Re: lpg

Hi what system are you intending on using

[diesel des]

Correct. Lpg ecu gets its input from the petrol injector. Then when running on petrol the Lpg ecu petrol output fires the petrol injector. On gas the Lpg ecu gas ouput fires the gas injector. This is replicated for each cylinder.



Sent from my LG-H955 using Tapatalk

[hunker7]

I guess nothing beats soldering. Looking at wiring diagram, I cut the wire at petrol injector, and connect the lpg ecu output? So essentially signal goes through LPG ecu before reaching petrol injector?

[diesel des]

I cut and soldered the loom. Less connections the better so solder joints are best.

Sent from my LG-H955 using Tapatalk

[hunker7]

Trying to buy as much as I can before fitting the LPG. So what connectors do people suggest to use when connecting to Petrol Injectors? I'd like to do least amount of damage to the existing wiring.

[prj]

Yes, "certified LPG installers" usually have no idea what they are doing besides just fitting the physical stuff.
And even then, sometimes the physical fitting is shockingly bad.

[hunker7]

Thanks guys for the explanation, now I fully understand why I need wide band lambda kit. I will get that too then when buying and installing the kit, not entirely sure how it works but I'm sure I'll get my head around it.

So if I understand correctly than "certified lpg installers" have no idea about this and they wouldn't be able to help me with this?

I am not tracking the car and it's just a daily I will search for a cheaper kit possibly.

Thanks again

[prj]

diesel_des nailed it.

Though IME after 0.9 it won't produce any more power and just increase EGT.
Also, EGT's will be higher than petrol at 0.85 I believe, if you do not adjust ignition timing.

Considering Motronic tends to run around 0.76-0.77 when it is detecting knock and around 0.79-0.8 in normal conditions, one can see why it is important to map it correctly.

[diesel des]

This is pre turbine temperatures by the way.

[diesel des]

Yes. Richer afr than 0.9 or 0.85 on lpg causes higher egt and power reduction on lpg. Spraying extra gas into an engine causes no cooling effect. Spraying extra petrol in does cause a cooling effective as it's liquid.

But on my car with an afr of 0.85 :1 temperatures are 30 degrees c cooler on lpg than petrol. It's just extreme rich mixtures like 0.75:1 that some people think are safer that cause problems.

[bernsaudi]

On LPG enriching the mixture has exactly the opposite effect compared to gasoline. It's a downward spiral from there - the ECU helps to melt the engine.

Do you mean enriching the mixture past lambda on LPG causes high egt?

[prj]

No need for WBO2...I've tunes 8 S6 on LPG / only 1 has WBO2/ - and no blown engine so far. You should be very creative and persistant to blow the engine with Motronic.

You will trash the head sooner rather than later if you let it build any significant boost on LPG without tuning for it.

EGT will be constantly high with gasoline style mixtures and gasoline ignition timing. Fuel will continue burning in the exhaust ports/near the exhaust valves.
The AAN heads already suffer from cracking near the valves, even in stock tune and improperly tuned LPG accelerates this significantly.

And you do not need to be persistent at all. Motronic always enriches the fuel mixture to combat possible high EGT's. On LPG enriching the mixture has exactly the opposite effect compared to gasoline. It's a downward spiral from there - the ECU helps to melt the engine.
Unfortunately as I have learned with LPG installers it tends to be the norm that they have no idea about the inner workings of engines let alone ECU's, at least in this country they just want to make a quick buck.

The OP's mindset is also disturbing "cheap cheap cheap cheap". If you don't have the resources to do it right, then don't do it all or wait until you do. I've seen so many engines messed up by badly tuned LPG in the past few years... and then it's full engine rebuild time in a good case scenario and replacement head in the worst.

[hunker7]

No need for WBO2...I've tunes 8 S6 on LPG / only 1 has WBO2/ - and no blown engine so far. You should be very creative and persistant to blow the engine with Motronic.

good to hear. I was thinking, I am not buying off the shelf kit, is there a software available that I can use to calibrate it? Or it comes with the ECU?

[doncecone]

No need for WBO2...I've tunes 8 S6 on LPG / only 1 has WBO2/ - and no blown engine so far. You should be very creative and persistant to blow the engine with Motronic.

[hunker7]

You should be fine. But ideally get a wbo2 and do it right.

If finance will allow it I will get it, but it's not cheap, I will look into cheaper options possibly.