can a scoob live of this substance? or does it cause them to die? is it a realistic option for an impreza turbo?
how long will it be before the government hikes the price of it up? just like everything else. my wages are the exception to this current trend.

 

bump

 

Why buy a high performance car extracting a lot of power out of 2 litres and then try to run it on gas? Would it not make more sense to look at a performance diesel if you are looking for good MPG with some performance?

 

The cost of an LPG conversion is about £2000. diesel is about £1.18 a litre here, diesel cars are more expensive to buy than petrol.
LPG is £0.52 a litre. if you drive 14000 miles in a year you have saved £1000 with LPG compared with a diesel. in two years you have paid for your conversion.
a performance diesel isn't an impreza with 280 bhp and rapid 0 to 60 times pin sharp handling out of the box instead of remap, bigger turbo, FMIC then new suspension. my questions were is LPG an option for an impreza? would LPG reduce the longevity of the engine? does anyone think the price of LPG is going to rise? also i was having a moan about the price of everything going up and not my wages.

 

someone else on here done this not read it through it properly though, Scooby LPG

 

Partly inspired by Wayne's own conversion I've decided to get mine done...

Will be going to a local LPGA approved place costing £1550 and an extra £75 for flashlube to be on the safe side! He's putting an 80 litre tank in the boot which can only be filled to 80% capacity to allow for expansion so reckoning on 64 litres of gas at 20mpg I should get a range of about 280 miles.. I normally get 25mpg so have taken 20% off as you don't get the same efficiancy out of LPG!

However at 47p a litre compared to £1.12 for Vpower I've worked out that it will take around 20 months to pay back (even allowing for £100 service every 12K and the flashlube top up's). I do 12K a year at the moment in a 02MY WRX which is almost standard...

The government have pledged to allow the difference in fuel duty to narrow by I think no more than 2p before 2011. So If I kept mine for 3 years I will have saved about £1500 on fuel and it will be 8 years old with only 61K on the clock!

So once the conversion is paid for I'm going to be driving a car with more performance than a 'performence diesel' at the equivalent of about 45mpg...

...and I don't need to buy another car with the huge depreciation that entails

 

How much weight does the conversion add?
How much load carrying space do you loose?
What power reduction will there be on an Impreza engine?
On a less stressed engine I seem to recall the power loss was advertised as "only" 15%. Probably more on a stressed, turbocharged 2 litre.
Do you have any figures?

 

Any more info on this?

 

Harvey,

My car is the one on Scooby LPG

You do lose power, although I only run LPG at 1 bar boost at the moment until I get around to logging egts. Its not much to be honest.

The best test is when I have it at 1.4bar and running gas. When it gets above 15ms petrol injector times it switches back to petrol and then you notice the difference. Not a massive kick, but certainly noticeable.

As for MPG, I get 19 - 20 mpg combined. I up the timing globaly 2 degrees when doing motorway runs. I have been keeping records of my fuel usage and after 2 -3 months its around 60% of what it would have been on V-Power, including petrol and flashlube costs.

The tank I have is the largest I can get in the boot. 80litres, although it will only take 64 litres due to expansion. The spare wheel tanks are just too small.

I dont need the boot space as I only use it to go to work. Its a daily driver until I get the new house built and once again have room for a toy. Didn't really want to sell the scoob.

Couple of things to consider.

The tank is HEAVY when empty, never mind when full.

The tank has no baffles, so when its near empty the gas can cut out and return to petrol when setting off sharpish in 1st or 2nd. Its not a bad cut, but I could do without it.

LPG has an octane rating of around 106 so increased timing is ok. I have tried 10 degrees extra which seems to take it way out of the best timing range, but still no increase in knock via the commander. At 2 -3 degrees it seems better.

The calorific value of LPG is only 85% of petrol meaning there is no way without a CR increase that you will see the same power as from petrol.

My DIY kit cost £930 inc vat and del.

I'm saving a genuine £100 per month. So in 9 months I have my money back.

I have found out how to start the car on LPG so have further reduced my petrol costs. I am due to remove the petrol cold start settings from the PFC as the gas simply doesn't need it with being so dense and cold. Again, this will reduce the fuel consumption. Problem with this is that if you drive briskly when the reducer/vaporisor is cold, it freezes and the car runs like a pig. Constantly freezing a vaporisor will eventually cause it to crack and render it useless.

Valve seat recession is possibly a problem on subaru engines. BiGas, Italy even state this in their documentation. When you look into it, any car that is a pig to reshim or adjust valve clearances on is also listed as having possible problems. To me its not a problem. If/when the valves start to cause problems, I will have a new 2.5 ready to go in. So in my case the 2.0 is really a test bed to see how things go.

Cant think of anything else a the moment.

I think that JGM is about to embark down the LPG path.

Cheers,

Wayne.

 

Ambo,

I don't think I payed £75 for my flashlube kit. Its only £33 plus vat from Tinley Tech LPG Equipment - LPG conversion kits, LPG advice, LPG parts

The flashlube itself is cheaper on ebay than anywhere else.

Cheers,

Wayne.

 

Also, a bit more info here.

https://www.scoobynet.com/projects-4...g-project.html

 

all being good my bigger power car I just built from rolling shell should be finished tomorrow (it needs a check over and road tax) but passed mot yesterday
so my other scoob can come off the road and it is ready for conversion.. I'll probably wait a month or so first though.

Simon

 

1550 is not too bad.. which company?

Simon

 

LPG does have a higher octane, and is a very valid fuel for a performance car. One thing you do lose out though, is the cooling effect of injecting a petrol liquid/mist into the airstream.

Not a big deal on low boost setups, but good intercooling is something that must be considered if aiming for higher power. I think most of the single gas regulators, only cope with about 350-400 anyway. Not sure if there are larger ones...but you can run 2.
There is a couple of guys over on the Legacy forum with gas conversions, and they are very happy.

I see no reason why a modern gas injection system, cannot be controlled with a typical aftermarket ecu ( most of the gas computers, seem to piggyback off the std ecu, still relying on what it tells it in terms of ignition, and injector opening ), and performance can be optimised on gas. With dual maps...one for gas, and one for petrol

And not forgetting. If your heating ran off Propane, or you had a boat that ran on Propane or LPG, you could have a tank installed at home, which could work out much cheaper than the road taxed LPG fuel.

Although at less than 50p/l even pump prices look attractive.

 

Wayne : Facinating reading and a good write up. Thanks for that. Impressed.
I don't want to run a Scooby engine on gas, as for me the extra weight and loss of space defeats the object of having a Scooby Wagon in the first place.
I do have some experience of running a fleet of Nissans on Calor and BOC or Calor, I can't remember which, supplied the refuelling equipment on quarterly rental. Basically a hand operated pump attached to large storage cylinder, perhaps 1.5Te capacity. Performance did not matter which is just as well as the weight was noticable. The only problem I ever remember was one in particular that suffered from icing, particularly when it was damp!!!
As Stevie points out, if you have tanked gas for houshold heating already, then the attraction can be even greater.

 

the home tank would need to set up to give a liquid feed to the cars tank as normally they give off gas.

I looked into this as we are building a new house and was thinking about having our own tank. I really dont think its a viable option to be honest.

Wayne

 

I picked up a new Forester XC run around the other month when IM were offering a free LPG conversion or cash. The dealer said go for the cash as the LPG savings would be wiped out by the cost of valve checks at servicing over 3 years.
This doesn't seem to be mentioned in the threads apart from Welloilbeefhooked - is it a minor threat ?

nick

 

stevie,
There are people using the megasquirt ecu to control the gas. I have thought about doing that and letting it run as a standalone system. The piggyback ecu does work well with the current setup but its still a pain having to run a petrol map.

Do the simtek ecus let you have a independant ign and fuel maps?

Also, i run a double vaporisor that will supply enough gas for 350hp

 

the flashlube kit if set up well should stop any valve seat issues. Thats SHOULD though and no one will give a guarantee

 

yes

as standard setup the second map is an offset ign, inj and boost (boost is independent already) but can be setup as totally independent too I believe.

Simon

 

Hi, Autogas Power in Ketley, Telford. Nick

 

Ok, thanks for that. The £75 is a fitted price, but I think I will buy one and fit it myself. The fitting instructions are available from Flashlubes website so i've had a read before I need to decide whether to go DIY!

Cheers, nick

 

do you know the goverment are going to start taxing gas at the start of next year. i read it somewhere a few weeks ago.

 

By then I will have my money back.

The other thing to consider is this. Do you really think that a "green(er)" fuel is going to be that heavily taxed by the govenrment? It may be higher, but as long as my overall running costs are lower then its still viable.

Afaik, the tax duty is remaining the same until the 2009 budget. History has shown that they have committed to a 3 year duty plan on LPG, so we shall have to wait and see what they come up with.

It's the people who wish to convert that would bit hit hard by this.


Wayne.

 

Once more people start using it, you can bet your life the government will start to tax it heavily.

The government doesnt give a toss about green, or the planet, or any of the BS propoganda thats out there. Its just another easy way to extort money from us.

Fuel duty is nothing but extortion. Dick Turpin wore a mask.....and is the spitting image of the current Prime Minister. Robbing *******s.

 

Bigas now offer a petrol added option on their software set up, this turns on the petrol injectors at high load/rpm times, also being billed as a preventative measure for valve seat recession, but personally Flash lube is a simpler option.
Tank wise, cylinders are not the best option really-we prefer to replace the spare wheel-even if this means the boot floor lifts a bit, also a torroidal tank should have less surging issues (but still not none!).

£1550 is about the going rate for a standard 4cyl job, if I was installing on anything hot, I would go for a siamesed vaporiser or a high output KME one-these are a little smaller with less pipe work to consider, injector nozzles would probably factory order 3.2mm or thereabouts-these upgrades would rush you about £50. Flashlube kit is £28 I think.

We converted older Subarus to single point (think pre-historic carb) with only minor issues, so a modern injection system should cope no troubles. Also the KME system we fit has graphed fuel mapping, for fine tuning under different load/rpm scenarios, so if your standard fuel mapping is working well, this will be matched or improved.
Rob (ex PP STi owner ).

 

Not sure where you see the 47pence LPG we struggle to get 59p now around essex. also seems harder to find anywhere. I know of there petrol stations.

 

Rob,

Maybe you could shed some light on the petrol contribution for me. I use the system (BiGas ECU) to switch back to petrol above 15ms. I have seen the function that allows you to add petrol in conjunction with the gas injection.

Now, if my setup will supply enough gas to support 15ms for example, and only that amount, then I could add an extra 2ms of petrol?

What if my injector times go above 15ms? What then happens to the petrol contribution?

I would have thought that when the gas supply maxes out it should just add the required amount petrol to compensate and not do either of the 2 methods above.

Cheers,

Wayne.

 

quite simple, DO NOT DO IT !!!! even with flashlube my '06 forester engine died of the dreaded valve seat recession at 60,000 miles. just in time for the engine out/new clutch/belts replacement stuff. my considered advice is not to contemplate an LPG conversion when some LPG companies have suspended sales of conversion kits and warranties on the rest exclude valve damage. stick to petrol !!

 

the fuel price will rise as lpg gets more popular as diesel has,it may take a while but any excuse the government get to rape us with higher taxes and costs they will.electric and hybrid cars will all go the same way until theres no oil at all left thats economically viable to extract from the earth