GTI Uses factory ECU, Remove Factory Injectors, Install GTI Injectors. Modify Factory Fuel Rail.

The rest is the same as a standard Conversion : Regulator , Line to Tank, Tank.

The trick with GTI is that you could always drill your manifold for a second injector and run both!. If theres room of course.

Nigel

just so youy all know. there is actually no LPi available on the market in australia. regardless of what you hear.
there is a vapour injection system available but from what i've heard it's nothing too special.

the vialle LPi system runs 2 injectors per cylinder, one for petrol, one for gas. the changeover unit is essentially a relay box about the size of a pack of cigarettes. when the car is on gas it still thinks it's on petrol and so self learns the mixtures etc.
the line pressure is at 5 bar above tank pressure and has a pump in the tank which swirls internally while it picks up the liquid.
only things i can see that are a drawback to the vialle system are that it uses a multivalve in the tank and so if the pump fails (none of the test ones have yet) you'll need to replace the entire multivalve unit. or if anything else on it fails for that matter. so it could be rather expensive.
the pumps have their own oil reservoir and liftscrew to lubricate it due to lpg not having any lubricating properties.

the current injectors in use have been tested to something stupid like 100 000 000 cycles (from memory) and there hasn't been any problems with them yet either.
there was problems with the first type of injectors tested but they have since been upgraded.

100000000 cycles doesn't sound like a lot (someone correct me pls if I am wrong) and definitely not in taxi terms.

Running two injectors will require special or modified intakes.

Using the same ECU for petrol and gas unless special signals etc are send to it probably be a problem, we all know a ECU doesn't learn that quick, if they did there would be other problems caused by this.

Multi valves suck, and you know that Scott, one of the reasons LPG fitters prefer separate valve tanks if they aren't just in it for the profit of install. (Pity Myttons stainless tanks were multi valves)

Will the fuel pump be as loud as it was in Liquid phases setup, reportedly it was loud, as would most fuel pumps being closer to the passengers. (We have probably all heard the funny noises from LPG tanks being so close to the cabin at times, and this isn't a noisy fuel pump)

How do they compensate for pressure changes in the tank with heated liquid LPG from pumping and running through engine heated fuel rails. Reportedly a problem with Liquid Phase in both versions of reusing petrol injectors (dual fuel using only one set of injectors) and separate injectors for LPG and petrol.

Guessing multi valve will require two lock offs, one for outlet and one for fuel return.

Sounds good they are using as non standard fuel pump, unlike Liquid Phases setup which originally used a Magna pump.

The ideas of liquid injection instead of vapour appeals to me because of intake temperature reductions, but will they have the same problems as other did with gas expansion being so high that actually interfered with air/fuel mix? Reportedly this was an issue with some early trials using standard petrol injector positions.

Liquid or vapour LPG contains no lubricates other than what came from the LPG bowser, liquid injectors in theory should be cooler because fuel flowing pass them, but will this be enough for durability over vapour injectors, hopefully GTI gets off the ground for us to find out as Vialle is definitely coming as it is already sold overseas.

Scott you are probably to young to remember how long a closed loop LPG system took to being sold as the norm, it was two expensive when it was first release, and as it hardly has any bearing on a taxi that is on and off the throttle all the time, so taxi companies weren't going to run out and pay close to an extra $1000 for using it, this might end up being GTI's selling point, if all they have to supply extra over a standard setup is injectors, modified fuel rail and special regulator, but remember to take out the cost of extra ECU controller, mixer and converter, I think GTI is on a winner, it wouldn't be much harder to fit than a standard setup and probably less tunning involved.

I would really love to see and use both setups in the flesh, to get a real comparison instead of theory and here say.

As with any LPG installation, LPG isn't petrol, it should have different advance curves for a start, higher initial (especially in a low compression petrol engine) and less total advance, I don't know if these requirements are within most ECU's self learn standard scope of tune, I am guessing not.

So for any type of install, I think they warrant either modified ECU's or piggy back units, for the LPG side to get full potential.

the switching box does have a couple of other little bits and pieces in it that intercept and modify the ecu's injector pulse to suit the application.
the conversion kit comes with an exchange manifold that has 2 injector holes per cylinder. one for the petrol and one for the lpg injector.
yeah, i hate multivalves. i can see it being an issue later on but apparently they haven't had any problems with em yet.
never thought of the pump noise. it'll probably be fairly loug\d come to think about it. being as there's nothing insulating it from being attatched to the body. it's metal all the way.
the presure is regulated to be 5 bar above tank pressure (i think there's an exact pressure figure there somewhere but it's about 5 bar above)
apparently it's gonna cost almost $1k more than the current closed loop systems but the selling points are there. less moving parts, more reliable, no backfires (not the type of backfires they get now anyway), better economy, more power, lower maintenance costs.
it's enough for the smart people to buy it. all the crazy arab's will prolly stay with the cheapest closed loop systems they can get hold of until they find out just how much cheaper running a cab is on LPi

apparently they've got a couple with over 500 000kms on em now with no injector, pump, or multivalve issues yet.

Would someone like to enlighten me about Parnells Sequential Vapour Injection set up.Sounds good and is available now.

Thanks for the replies everyone,

and yes I'd appreciate any documentation that any of you have on the subject.
What is this multivalve you refer to? The self lubing pump sounds cumbersome and interesting at the same time.
I actually saw an EL with the Liquiphase brand system on it many years ago...it had some pretty fundamental problems but ran very well when actually switched over.
I am interested in liquid injection mainly because I know it can provide the power and torque and probably most importantly the throttle response that vapour cannot.
If I can get a system that works like petrol injection I won't bother with dual fuel at all.
Another idea I've had is to use double injection ie; vapour with petrol for transient fueling. So a fuel rail with 8 injectors and Gas rail with another 8 injectors.
Of course this all means extra weight and complexity so liquid would be the way to go in the end.
Nige, what was your EEC catch code again?

Cheers,
Pete.

I did email and corresponded to someone at the university that has or had Liquid Phases patents, lost the email, lost the URL to the uni's LPG web page.

This is the only magazine article I could find, I had or still have (lost) later articles about using separate injectors instead of dual fuelling through modified factory injectors.

If you can get onto the bloke who owns this car or did own, he might be able to tell you the URL or university that now has the patents.
http://homepages.tig.com.au/~dolls/xe/main.html
This bloke did have LPG injection. I did have his email address (lost it), I contacted him originally through his sister, found through the web page. (cant find it now)

NO s**t

hey scott want to try again LOL

mm that info is really good and expaions the multivlave so i can understand it LOL

You wouldn't be being sarcastic would you Frank?


What explanation did you get shown about the multi valve.

Basically all a multi valve is one assembly that contains all these devices in one valve:

1) pressure relief valve.

2) fill valve (one way valve)

3) AFL (Automatic Fill Limiter, stops tank from filling more than 80% to allow for expansion).

4) fuel level sender (AFL float is combined with this)

5) Outlet tap & valve (contains high flow lock off in case of accidents etc, still allows small leakage to allow line pressure balance)

6)outlet lock off solenoid.

Non multi valve tanks contain these separate valves:

1) pressure relief valve.

2) Fill valve (one way valve), AFL and fuel sender. (Automatic Fill Limiter, stops tank from filling more than 80% to allow for expansion).

3) Outlet tap, outlet lock off solenoid & valve (contains high flow lock off in case of accidents etc, still allows small leakage to allow line pressure balance, these are all normally one assembly these days)

Probably forgot something but this will give you a general idea, problem with multi valves is they are generally a throw away unit, they are normally more problematic (valves and senders) and expensive.

Separate valves allow for separate valve replacement, reducing repair costs, they are far cheaper.

Every 10yrs LPG tanks have to be checked and relief valve is replaced, if the other valves are not faulty they do not get replaced.

I am sure Scott could post a better description and cost differences as he is currently in the game, not like me where it has been a long time.

no sarcasam at all,, umm i got an email here somewere u want it pm you email addy and i forwad it i think...

Unless it has copyright issues, just copy and paste the info in here, I think most members would all like to read about it.

You can email damage181@yahoo.com if you want.

xr9, the vialle system will be sold as a dual fuel system and will come with an exchange manifold to run a petrol and a gas injector per cylinder.
in terms of power, they dynoed their test unit BA's after converting them. 2 straight power runs, same time, same dyno, same day. the lpg ran 2hp higher than petrol at the treads.

Get onto Vialle/Boral and advise them that they have no real web marketing available, here or overseas, Vialle doesn't have to disclose all information but it really keeps everyone in the dark.

Here is Australia this is about all we get, and this isn't from Vialle.

http://www.alpga.asn.au/documents/Injec ... utogas.pdf

well you just got a whole bunch of info :p assuming i sent it to the right email addy.