Gday everyone, ive been away recently, spending lots of time researching water injection, talking to a few engineers and chasing up the parts i need for WATER INJECTION For an lpg fuelled falcon (hopefully the result on lpg will smash the result on petrol.
Ive noticed that people with lpg seem to give up there, they have found their happy spot for economy, sure its cheap, but its not free yet

Only a 5 - 10% economy / power gain, your engine stays immaculately clean and its good for the engine life also
This was a quote from an engineer friday, i have heard this from a few qualified people also; three engineers and two mechanics.

Here are the parts needed:
-DIY frequency switch which is available from Jaycar, i will put this together in the next few days.
This gets hooked up to wires reading the rpm of the engine, is adjustable (ie what rpm the switch turns 'on' and at what rpm it turns 'off'.

-Pump, still sourcing a pump that will do high pressure, low volume, not too low though.
(Only drips are needed, anything more will 'wetten' the spark).
I tried running a washer bottle and its pump for 10 - 15mins in a closed loop, the pump got very hot, thought best not to use it as a fail seemed likely.

-Injector / spray nozzle - still sourcing, as above, will require a low volume, high pressure nozzle.
This may not be a concern, maybe an adjustable copper valve can be used


The process:
The rpm switch will hook up to the pump, which i think will be set to turn 'on' at 1600rpm, but not at first, ill start at 2,100 or something high enough so if there is too much water, the idle down may flush it out.
-Thats really badly assumed logic, if anyone can suggest something better
A well trained auto elec from jaycar commented "that low?" when i suggested 1600rpm. As this is for cruise speeds, not extra power as such, im looking to gain as much economy as i can.

The spray nozzle will enter the throttlebody after the piece which twists as the accelerator is depressed. The water 'drips' in here, at a set rate

The pump will run from a washer bottle or something similar, through small piping in a closed loop into a T intersection copper piece which will lead to the adjustable copper piece entering the throttlebody, pre set to 'drip' at a low rate.

The throttlebody will have the nessercary hole drilled into it, from which i will put a thread into the hole to suit the spray nozzle, as i want to be able to remove it, replace it and adjust it.

I think i may have missed a few things, if i have please be nice
If you have anything to contribute, please do, i am going into a new territory, one which not many others have gone into on the new EFI cars.

I have compiled a document which is 5pages long and suggests 15+ ways to increase your mileage very easily, all ranging from 5 - 10% gains, there are 3-5 offering 30 - 40% gains also.
So if i can do say 5 of the things on the list, which i will post up later this week, then i can gain a 50% odd increase in mileage.

This was posted in 6cylinder, as opposed to alternative fuels, as the water is not an alternative fuel in this case and as more people frequent the 6cylinder forum, more exposure will give me greater results.

Im sure you all appreciate that im looking to hear from people with experience in this area to help me out, just a few lines of advice would be great, i dont want to hear "Thats stupid, why do that?" from anyone unless they have done it.

Thanks in advance
Matt

How will the LPG system know that you are using water in the intake? Wont the LPG system still inject the same amount of fuel meaning your economy wont change?

Ive heard of water / meth injection to help reduce pinging but I have never heard of it being used for economy.

Do a google for snow performance water injection to get some ideas of what is currently being used.

My old man did this years ago but on a carby engine. The water itself when turned to a gas form contains oxygen for a smoother longer "bang".

Im not sure how the ecu interacts with the gas system exactly, although the sensor in the exhaust measuring the level of oxygen will make changes to the petrol injection, maybe it will lean out the gas, or not.
Im betting that it wont do this, but require less pushing on the accelerator to get to the same speeds due to the cleaner engine, the 'smoother, longer bang' and slightly higher compression, this along with advanced ignition timing, if i can

Have you considered how the pressure varies on the engine side of "the thing that turns"? This is why the fuel pressure regulator is vacuum compensated and the same reasoning should apply to your water. The fuel injection also takes a lot of other factors into account before operating the injector perhaps you would be better to tap off the injector signals to control your water too.

Good Luck,
C

Google"water injection systems" and find thousands of up the minute water injection systems and advise from people who have done this already

Thanks GtBob, already done alot of that, no one seems to have 'the answer' though, plus i want to rethink the whole thing through having already seen everyone elses idea.

Thanks everyone else

If you run the pipe in copper and wrap it around the exhaust you can get steam injection AFAIK much better than water injection. You won't need a high pressure pump nor a nozle.

EDIT :
found a site that discribes it.
http://better-mileage.com/water4.html

Thats a great twason, after reading through alot of those pages, woulc it be possible to inject the steam into the throttlebody instead of into the pvc inlet (which only allows a small amount of vapour in)?

Thanks again

I suspect that the vaccum differential is the critical part to its operation and would need to be plumbed in as described.

just some thoughts I've had after reading this...I'm not trying to be smart or bother anyone or step on toes, just my ideas...
that site on the vapor system seems less than professional in many ways... ive got no experience with water injection but from what I understand its used to stop pre ignition in turbo cars running high boost, or high compression cars (as you are aiming to do)... its easy for them to say you need to compensate the O2 sensor, but that will obviously give you better milage if the ECU thinks the car is running richer than it is... how do you know thats not going to cause your car to run lean and wreck the engine? the water injection may cause a better burn and produce more power with the same amount of fuel, so as you say you wont need to accelerate as much... but i dont think you should need to change the O2 feedback to the ECU... just sounds like a really bad idea to me... please dont take any of this the wrong way, im not bagging anyone out its just my thoughts, i might be completely wrong, thumbs up to you for trying something new anyways and i hope it all works out, let us know how it goes

i agree with you zxhoon,
leaning the engine out, just like running too high'er boost, must be done very carefully and you need to know how to maximise it without doing any damage.

I figure, i ask a handful of half / fully qualified people their opinions and from there i make my own mind up, based on my own logic, ideas and knowing when i am being s**t.

You raise a very valid point, adjusting the fuel / oxygen inputs into the ecu can potentially lean the engine out too far, the water injection will compensate for this to a degree, another question i need to ask other users here is whether or not the cars temp sensor will give me any indication on whether or not the engine running lean will result in a higher engine temp.

Thanks for your input!
Matt

Bear in mind that the link I gave you is for a site focused on improved economy and you need to take the water injection notes in that context. I would not alter any ECU mapping without having the appropriate measuring equipment, in this case a exhaust gas analyser. Water temp is of no use as a gauge of mixture. Your original post suggests LPG is your fuel of choice and running lean on LPG burns colder not hotter as does petrol.

yeah, water temp will be far too slow reacting and wont indicate much at all...

exhaust gas temps however would be something to look at, but thats pricy gear... depends how much you want to chase economy and for what reasons, saving the environment and finite resources, or money in pocket... theres a point you will reach pretty quickly where it wont save you any money...

on a side note there is some interesting stuff being done with lpg and diesel engines that improves economy and power, etc quite a bit... interesting stuff...

glad i didnt upset anyone, ive made posts on other forums with my thoughts and been flamed before good luck with the efforts anyways

Haha, there are a few people on forums who come across badly, like A grade C###'s, but your not one of those

That page suggests that the vapour injection will ONLY benefit by adding a diy mixture controller, you'll see it if you read through it, ive read about 15pages from that site about the vapour injection.

I dont know where the 'PVC in' and 'PVC out' lines are?? Can someone help me there?

Thanks