LPG mpg

[fassi1]

yeah i couldnt remember the name so i just put pump but it has come to me now and it is the magic jet vapouriser what is good for high bhp so when you put your foot down it doesnt cut your gas out and the power is like using petrol.

I'm really sorry but what a lot of rubbish.
Magic jet is the name for injector, vapouriser is called magic III, which is to small for VR4. This reducer is well known for its dangerous failure.
Some of the inside seals fail and about 7bar of liquide gas enters cooling system, which most often can't take such a high preassure and causes radiator or other parts of cooling system leak, crack etc.

[hardarse]

hey whats with the negativity im just saying what i have on my lpg and if i dont get the names right whats the issue and if they have issues with these things mines been working fine upto now and if it does fail which vaporiser is good then to fit

[fassi1]

There is no negativity at all, just real truth and i don't mean getting names wrong.
Whoever said:
"the magic jet vapouriser what is good for high bhp so when you put your foot down it doesnt cut your gas out and the power is like using petrol."
made it up without testing this reducer.
I'm gonna say that again, there is no negativity, i'm only sharing my experiance.
1 reducer magic III tested on Audi A6 2.4 170bhp was enough and can manage no more than 200bhp.
2 reducers magic III tested on Audi A6 4.2 340bhp just done the job.
1 reducer magic III will never do the job properly on 6A13TT.
High gas pressure drop will cause injectors duty cycle overlap what makes fueling impossible to control (stable AFR) which means bad economy and power loss.
More gase pressure drop will cause lean mixture (high EGT) under WOT and in worst case scenario misfire.
I mentioned common failure cause I've experianced it on my car what caused massive radiator crack, I was lucky i was few miles from home.
Replaced few of those reducers on customers cars with the same failure.
Important is fact that most of the manufacturers reducer's specifications are far from truth, what has been proved many times by testing each of those products on many cars.

[hardarse]

so which vapouriser is good for these cars then.

[fassi1]

2 mid size reducers, I would recommend KME Silver.
If you want 1 reducer it can be only Prins.
No other single reducer will supply enough gas for this engine.

Very important is to have multivalve extra (bigger ID output) fitted on the tank and 8mm OD copper tube or equivalent of flexi pipe running
from the tank to the reducers.

[Nick warwick]

Any more mpg stats? What you guys getting on petrol?

[ex-derv]

hate to agree, because I have a single vaporiser rated to 500bhp, but it doesn't seem to handle the fuel demand and cuts to petrol under high load although they are well known for use on supercharged range rovers. The injectors nozzles are the biggest they can be too. I know ian has the same issue but couldn't tell your which vaporiser he has.

Any more mpg stats? What you guys getting on petrol?

I get about 220 miles off a fill up of v power before the fuel light is on most of the time - I cruise about a fair bit but it gets regular working over too. On LPG the tank of petrol lasts 900 - 1000 miles and I get 180 miles out of 47 litres of LPG on top of that.

The main problem it has is it coughs and misses when it's wet or cold, once the engine is hot. I'm hoping this is a mapping issue to do with it running lean (and that Chris can sort it at eurospec )

[adaxo]

single vaporiser rated to 500bhp

Yeah, working great and cope with demand of 500 bhp engine easy, on idle

they are well known for use on supercharged range rovers

May that's why there are so many broken ones

[ex-derv]

not saying it works properly - just that that's what they claim. Ideally I'd like it changed to a twin set up but it's all ££££ - had 2 lots of car tax and 2 MOT's this month already (although the vr4 went through without even a single advisory (except the chip on the windscreen but you can't blame mitsi for that!))

[adaxo]

not saying it works properly - just that that's what they claim.

I know Tim, hope we manage to made your setup run safer at RR in eurospec. I would suggest (just for time needed to saving for second vap) to set your ECU to run on gas up to, say, 3000RPM and then switch to petrol above this rpm then back to gas below, of course if your ecu allow to do this. This is just to mask the problem temporally and as said above just for time being until you could add second vap and then enjoy the whole rpm range safe on gas only.

[ex-derv]

4000 would be better because then it would cover all normal driving around town. When you say 'safer' what do you mean could happen at higher revs than that?

[adaxo]

Revs mentioned is just a guess, I mean, its probably too lean when on boost, it could be, for example 2200 rpm, I don't know, only way to find out is to stick wideband in exhaust and test drive.

Running lean is VERY dangerous/destructive for engine, it will increase exhaust gas temps to unacceptable level and then many bad things could happen, like oil will not lubricate properly any more, higher temps are not healthy for all rubber components in heads, head itself could crack, walves can stick, pistons could be damaged ect. ect

[ex-derv]

ok, I get you - really really bad then! Gently does it on gas until we've had a proper look then.

[fassi1]

I would take the nozzles out completeley Tim unless they are drilled out with min 3mm drill bit.
What kind of reducer do you have Tim?

[paulg23]

I have a Magic Jet on mine. 20,000 miles on it so far and all ok. I always switch to petrol if I have my 'hooligan' head on. For every day driving it is more than adequate. Mine misses and pops on gas when it is damp. (ok once warmed up). Im pretty sure this due to needing new ignition leads. LPG has a higher ionisation voltage than petrol so leads that are getting a bit tired can break down on LPG.

[elnevio]

ILPG has a higher ionisation voltage

A what now?

[adaxo]

A what now?

'Harder' to ignite

http://www.afcintl.com/pdfs/RAE%20pdfs/ips.pdf

[ex-derv]

I have a Magic Jet on mine. 20,000 miles on it so far and all ok. I always switch to petrol if I have my 'hooligan' head on. For every day driving it is more than adequate. Mine misses and pops on gas when it is damp. (ok once warmed up). Im pretty sure this due to needing new ignition leads. LPG has a higher ionisation voltage than petrol so leads that are getting a bit tired can break down on LPG.

I put magnecor kv85 on mine and it didn't make any difference

[fassi1]

I know somebody who has done more than 50K miles and still ok, but you never know.
LPG likes single elctrode spark plugs with about 0.8 gap.
If you run wrong plugs with bigger gap or plugs haven't been changed for long time or your leads are getting tired that will definitely cause missfire on LPG noticable at the beggining at low revs and high load.

[ex-derv]

I would take the nozzles out completeley Tim unless they are drilled out with min 3mm drill bit.
What kind of reducer do you have Tim?

IMAG0736.jpg

does that help? It's on a zavoli alisei n system