Now before people say go speak to your L.P.G. mechanics, I havn't found one here that I trust yet! In the past I would of gone to scott with my questions...

What I'm wanting to know is what other options are avliable for me for the point were the LPG mixes in with teh air at the throttle body.
Because at the moment I've got a BBQ buner type thing fitted into the air intake piping just befor ethe throttle body, and it severly cuts down the size of the hole the air can flow through - at this point the air has 2" or less, compared to the normal 3"'s. Does anyone have a different/better set up? Or know of one? Maybe some sort of spacer thingo that goes between the piping and throttle body, not in the piping, allowing it to be bigger? And does anyone know what this peice is called?

Now I've seen systems like fuzions were the induction piping runs right to the converter then to the throttle body, but that's not really an option for me as it'd involve a new converter and what not to.

yeah i know what you mean, the hole in the mixer is a bit small, it's OD is 76mm, don't know what it's ID is

only relatively easy thing i can think of is something like a cone to direct the airflow into the mixer instead of the air having to find it's own way in ... i was going to try getting a metal funnel and trimming the bottom off until it fitted into the mixer neatly and then cut the top part of it until that fitted into the induction tubing in a neat way also

the thing that complicates using a funnel tho is the difference in the angle to two things are, the funnel would also have to allow for this angle .. if someone was good at sheetmetal work it wouldn't be too hard for them to knock something like a funnel with an offset in the end of it that would be the same as the join at the induction tube and the throttle housing

mm not much u can do.. maybve change to lpi

OR hehehe

go for a twin mixer setup but then that will prolly mean twin convertors....

Not the answers I was looking (or hoping for).

So no one seems to make a larger ring sprayer thingo? That's just stupid!

AFAIK, with any LPG mixer system, you need a venturi to create the needed vacuum to allow things to work correctly.

If you hand built a complete 6 inch intake, you would still have to use a venturi of sorts to allow the gas to be sucked in. That's why every LPG system you see other than liquid injection effectively throttles your intake a little. Theres nothing you can do about that

Even if you place a big trumpet in you standard intake to increase the air volume at speed, then you will run into other issues much like a turbo LPG installation. In a turbo LPG install, i believe you need to run a vacume line to the LPG converter and the system is then very critical to where you get your vacuum from.

The other thing to consider is that it is illegal, at least in victoria, to work on the high pressure part LPG system. That means you can't even change or modify the converter yourself In theory, if you have an accident and it is found out that you worked on the high pressure part of the LPG system, your insurance will not pay out, in theory.

For me this law is a real problem as i was reading up quite a bit on LPG systems and was considering doing my EF I6 and my turbo landcruiser (diesel and LPG at same time) but i could not find anyone that would certify it once installed

Interesting, I am not sure you can use LPG on a diesel, I believe that you need LNG and the downfall is the lack of refueling stations, correct me if I am wrong on this.
Cheers
TW.

yes you can run both at the same time, you get more power and more economy and greater range, only thing to watch out for is overfueling but with modern systems its not really an issue

re the ventrui issue, yes of course it's got to have a venturi and i think that if there was a tapered cone like thing leading into the mouth of the venturi it would still work, after all thats how some carbys work with ram tubes attached to them, long as there is a low pressure zone to create suction it'll be ok

yes the laws the same in WA, i suppose its to stop, or try and stop, d***head from doing bodge jobs ... doubt if it does tho

Hmmm... That sucks.
I remember that story about the d**k who put a backyard LPG install into his old X-Series Falcon, driving a long kids said they could smell gas, he told me they were dreaming, lit a cigarete and boom, he left his kids in the car in the fire, tehy had to get themselves out.

I removed the mixer a turner the centre out of it on the lathe while still keeping the venturi effect with an angled cut. It increased the i.d by almost 10mm. Ran the car on the dyno and checked a.f, which was ok with a small adjustment. Car made an extra 4rwkw. not much i know but the torque difference was noticable.

thats on a v8, but should be similar on i6

just a thought, maybe a better shape would have a tapered bore with the gas holes in the rear face instead of in the centre of the bore

so, the OD of the mixer would be 76mm, same as stock OD, and the ID of the bore tapering from say 71mm to say 60 or 56mm or so

from a machinists point of view it shouldn't be too hard to make, make it in 2 halves, OD side and front face(71mm Dia) on one piece of metal, sort of L shaped and ID side and rear face(60 or 56mm Dia), with gas holes in it, on another piece of metal, just weld the two together to make the complete shape and drill a hole in the side and weld a short piece of tube to it to connect the gas line to

might see what i can do at work when things are a bit slack, i've got access to all the stuff needed to make it up

thats basicly how mine is. works well.

I was also pondering this not long back. I decided to remove the venturi and do a petrol before/after test to determine if there was much restriction. While I didnt run it on dyno, I tried to create similar conditions and determine how much effect it had. The difference was bugger all to say the least.

For higher power (I probably only have around 120rwkw) maybe its worth modifying, but if your looking for a bit more kick on a stock engine I certainly wouldnt spend money on bigger, fancier mixers.

I might add my mixer is very restrictive, it almost halves the intake diameter.

bug, i did this also but did dyno the car, there was a 5 rwkw difference.
hardly noticable as you said.

hmhmhmm interesting