i can 100% tell you the mixer ring restricts power.
i did drag runs at heathcote with my mixer ring in, then out and there was huge differences.
major losses in an LPG system are intake manifold volume taken up by LPG and the inlet restriction.

and even the price of converting from a normal LPG install to an LPGi install is massive, way more then the idea of developing a swichable pipe.

i can see NO reason why it woulnd't work.

Yeh unclewoja, i know you didn't convert your car and that it was purchased on the 28th with an ELKO system that you described as gutless in another topic you posted.

Any comments i made regarding (tick)ford were there to highlight that even big budget manufacturer have as yet not improved power output on converter based lpg systems as compared to petrol injected systems (though they are close). I never said your car has a tickford system.

My view is that any carburettor type system is a poor cousings to any injection based systems whatever the fuel.

Again, my view is that if you want more power and the economy of lpg, you can't go past a liquid injected lpg system. This will become apparent when such systems start to come onto the market and people start to drive these cars. At this point, if you still had a desire to run one fuel, it may become lpg you pine for.

As for my comments related to power loss due to an intake restriction caused by the mixer, it seems that my view of an appreciable power loss is very differant to others but i never said there was no power restriction or power loss. Guess appreciable is just a little too subjective a word so i will agree that there are gains to be had by removing intake restrictions.

Pity EFFalcon didn't post any data on his heathcote runs as this would have been interesting but i must say, wide open throttle runs are a very differant world from daily driving.

As for your desire to build a dual intake system, i still feel that this is a complex undertaking and aproaching the problem backwards. A liquid injection system on the other hand will allow you to obtain more gains once it is installed by following the normal aproaches of intake, exhaust cams, and engine managment mods.



You made the above statement but you fail to see that i have challenged this view and also failed to see what benifits an liquid injected system will provide as it solves so many of the problems that cause a lower power output compared to petrol. Liquid lpg injection will give you the best of both worlds and more. Imagine what (tick)ford could achieve with such a liquid lpg system if they are within 7kw of a pertol injected I6

Why ford has tested a number of cars (>50) running lpg liquid injection and not yet released such a systyem says more about ford and its customers than it says about the system itself. Make no doubt, when you see it it will blow you out of your seat.

If it is cost that is a real limitation, then i would suggest save your time and money by making sure the current system is well tuned. Then when liquid lpg injetion busts onto the market place, take a lok at it and then you can make a better informed choice of how you want to solve your problem.

If dual intake is what you really want to do, i do wish you luck and hope to read some post in future with some data to back claims of improvements.

Cheers, Itchione

Ok. Let me get something straight. My views on fuels is this:

I don't want the LPG system to create more power, I want the petrol system to create the power it can.

in my view, LPG = cheap, petrol = power

According to this site and this site, the calorific values of petrol and LPG are actually the same (you need to do some converting because the calorific values are quoted in different units. see google's conversion here

So, assuming that information is right, the extra power you get from an LPG injection system is purely from the optimised spark timing. If you optimised the spark maps for petrol, you'd get the same power outputs.

for identical systems, and if both are tuned to their optimal.

the petrol system would make a little more power.
no matter what was done to it its just the properties of the fuel.

liquid lpg injection removes lpg vapour from the intake plumbing leaving more space for air.
liquid lpg injection cools your intake air as it turns to vapour.
liquid lpg injection allows better control of fueling as the ecu allows you to control all sorts of parameters to optimise the burn.

There is much more than just optimised spark timing at play with liquid lpg injection

All these will give power improvements above what (tick)ford was able to accomplish with their converter based system (which most would agree was rather good for it's time).

lpg also allows you to increase compression as lpg has a higher octain rating than even premium unleaded.
And then there are the other more familiar engine mods one could also apply to such an engine giving other improvments.

My beleif is that a liquid lpg injection system will give more power on a mechanically identical engine running petrol as the ecu can be optimised for the specific fuel used. A dual fuel arrangement is also possible but then the question would be why would one bother, and the only answer would be that access to lpg may be limited in ones travels.

Check out this site here for just one injected lpg system which clearly slows an improvement over premium unleaded.

Again, for me it would be more interesting to develope an liquid lpg injected system rather than play with dual intakes but we know that already

It's strange that you want petrol power even if an lpg system could deliver more.

In truth i can all too well understand if cost is an issue and maybe we should drop such discussions on the merits of liquid lpg injection and get back to how you propose to handle the piping so that you don't choke the little power available out of the current lpg install you have in your EF.

As for the site links you posted, i haven't looked at them yet but will do so later as i thought lpg had a slightly lower calorific value than petrol.

Cheers, Itchione