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VZ LPG Conversion

heronvzexecutive

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Hi,

Sorry if this has been asked before but i'm so terribly inept when it comes to JC and my car.

I have an 05' VZ Exec sedan and was wondering whats the deal with LPG conversion.

1. What is the total cost of conversion after rebate?
2. Is the fuel cost going to be dramatically different (I drive around 20,000kms a year)
3. Does it effect the resale of the car?
4. I plan to run my car into the ground over five years until I finish uni, will it last this long? will it have any mechanical problems due to the LPG.
5. How does the fuel gauge work? Does it show the petrol left or the LPG left?
6. Will the display show the km's left, dist to empty etc when running on LPG?
7. Is there a button to switch between petrol and LPG?

I appreciate any replies,

Thanks.
 

poweredbycng

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1. What is the total cost of conversion after rebate?
Roughly $4000-$5000 before Federal rebate (the rebate sits on $1750 at this time) depending on what type of system you opt for (i.e. gas injection or liquid injection) and the type of tank you opt for (standard cylindrical vs. toroidal / donut-shaped). That equals $2250-$3250 after rebate. Since all VZs were built after 1/1/2004, you will need an emissions-certified system and that means injection is your only choice.

2. Is the fuel cost going to be dramatically different (I drive around 20,000kms a year)
Find out how much petrol you use (L/100km) and multiply that figure by about 1.3 for a ballpark gas consumption figure estimate (i.e. you'll use somewhere in the region of 30% more gas but chances are you will get a pleasant surprise in this department).

3. Does it effect the resale of the car?
Yes, in a positive way. LPG cars are selling for a healthy premium over petrol-only cars these days.

4. I plan to run my car into the ground over five years until I finish uni, will it last this long? will it have any mechanical problems due to the LPG.
Like anything, if you look after it, it will look after you.

You will notice that any problems will pop up on LPG well before they pop up on petrol (e.g. worn spark plugs and coils will cause misfires and surging on LPG long before the problem shows up on petrol).

5. How does the fuel gauge work? Does it show the petrol left or the LPG left?
The fuel gauge / fuel selection switch is a single-button affair that has a cluster of LEDs showing you the approximate amount of gas in the tank. Some gauges will have additional LEDs to show you what fuel you're on, but the Sprint Gas gauge on our VZ SV6 switches all LEDs off completely when petrol is the selected fuel. Your petrol gauge will only show the amount of petrol left in the petrol tank. Switching between fuels is as simple as pressing the button on the gauge and this can be done at any time under any condition. The fuel switch-over is seamless and you don't feel a thing.

6. Will the display show the km's left, dist to empty etc when running on LPG?
Our VZ SV6 does, but you'd be nuts to rely on it for any kind of an accurate reading.

7. Is there a button to switch between petrol and LPG?
Please see above.

Download my LPG Savings Calculator HERE.

If you have any more queries, please don't hesitate to ask.

Regards,
Dave
 

jimmyd17

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I was speaking to an LPG fitter a while ago about VZ's on LPG and he said they can do a mixer setup which is cheaper than injection, but only on cars built before September 2005. I haven't researched any further so I don't know if this is definitely the case, but that sounds contrary to poweredbycng said about the cut-off date being 01/01/04. Just passing on what I was told. Hope that helps.
 

levymetal

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i would just go with the mixer setup. it's in the gas installers favour to install vsi instead of a mixer anyway, so he wouldn't offer a mixer if it wasn't legal. there may be different laws in different states.

vsi is definitely a better setup, but in terms of money, you'll break even around around about 1 year after a mixer type setup, and 2 years after vsi.
 

poweredbycng

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I have personally NEVER seen a VZ with a mixer-based system and would NEVER recommend anybody install such a system on one. I have asked many taxi drivers with VZs and they all have injected systems (either HSVi-fitted or aftermarket). One of the major issues is the design of the Alloytec intake manifold. it doesn't take well to even the smallest backfire and will rip to shreds in case of one.

Another issue is that the Alloytec is a high-revving engine and fitting a restrictive mixer in the intake system WILL impair performance at above 5000rpm.

And lastly, traction control will be completely disabled if you fit a mixer-based system.

For those who are interested, emissions compliance is a national requirement and applies to ALL cars built after 1 January 2004.

This requirement is where a vehicle converted to LPG, that was manufactured on or after 1 January 2003 for NEW model introduced vehicles and all vehicles manufactured on or after 1 January 2004, be fitted with an emission certified LPG system.

If it is found that a vehicle, that fits the above criteria, is fitted to LPG without an emission certified system, then that registered business may be required to have that vehicle presented to an emissions laboratory for either an IM240 test or a full ADR079 certification on that vehicle, at the Registered Businesses cost.
Regards,
Dave
 

levymetal

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funny that taxi drivers would install a better system, considering how much they drive :whistling:. i highly doubt that a backfire would blow apart a manifold anyway. if you have NEVER seen a vz with a mixer then how on earth do you know how the manifold would cope with a backfire? evidence please.

how often will the op rev his car above 5000rpm, and how long will it stay there for? it looks like the op just has a normal car, who drives it under normal conditions to get to uni. 5000rpm - once a week for 2 seconds - doesn't actually matter. we're talking like, what, maybe 0.1 seconds off his 0-100 on petrol? i drive a v8 with a gas ring, the most restrictive setup, and it didn't affect my power on petrol.

at 20,000kms a year, it's going to take him ages to get his money back on the vsi. too long in fact, for very little benefit (for him).

can you also please provide a link that proves a mixer type setup does not meet emissions compliance.
 
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poweredbycng

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funny that taxi drivers would install a better system, considering how much they drive :whistling:. i highly doubt that a backfire would blow apart a manifold anyway. if you have NEVER seen a vz with a mixer then how on earth do you know how the manifold would cope with a backfire? evidence please.
Most LPG-fuelled VZs are HSVi installs. HSVi installs consist of the IMPCO-BRC Sequent 56 system. Aftermarket installs can consist of anything but let me tell you that the Sprint Gas/OMVL stuff runs so well with the Alloytec engine that it's not funny.

On top of what I have already said, the Alloytec engines have a composite intake manifold design and a drive-by-wire throttle which does not behave well with mixer-based LPG systems. Also, mixer-based LPG systems completely by-pass the petrol ECU air/fuel mixture controls and you WILL have issues with Check Powertrain lights etc.

how often will the op rev his car above 5000rpm, and how long will it stay there for? it looks like the op just has a normal car, who drives it under normal conditions to get to uni. 5000rpm - once a week for 2 seconds - doesn't actually matter. we're talking like, what, maybe 0.1 seconds off his 0-100 on petrol? i drive a v8 with a gas ring, the most restrictive setup, and it didn't affect my power on petrol.
You can't say that your power on petrol is not affected with a ~50% reduction in intake manifold diameter. This WILL affect performance on petrol as less air in equals less fuel burnt. Again, this is most noticeable at high revs but the impact can most likely be felt throughout the rev range.

As for how long you'd spend above 5000rpm? I'd say quite a bit, because the Alloytec is such a rev-happy engine and struggles at the low end.

And I would say that a mixer-based system on such a rev-happy engine where the power is achieved high up would impair the 0-100km/h time by two seconds.

at 20,000kms a year, it's going to take him ages to get his money back on the vsi. too long in fact, for very little benefit (for him).
You wanna bet?

DOWNLOAD

can you also please provide a link that proves a mixer type setup does not meet emissions compliance.
Ask any DECENT gas fitter and s/he will tell you.

Regards,
Dave
 
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