LPG Chimaera (Follow My Conversion)
Discussion
Hi Hugo,
The advance curve will be very different on LPG.
In the simplest terms LPG requires a lot more advance early on, but as engine speed rises the curve will flatten significantly when compared with petrol.
It is of course more complicated than this, as we know the picture is a three dimensional one, strategies will differ between the fuel types under the same RPM, air temperature & load conditions.
Fuel & ignition requirements work hand in hand, alter one & the other will be affected, but it's the different ignition requirements of LPG that are most often the downfall of a lesser conversion.
This is the reason why the ignorant continue to insist LPG will lose you power.
The truth is LPG shouldn't lose you any power whatsoever, this has been proven time & time again & in the real world, modern systems have banished the LPG power loss theory to the history books, FACT!
It's almost always the crude ignition control systems that conversions are often burdened with that are the culprit.
Sadly some people are still reading the old history books and really should update their knowledge on LPG engine management systems before making the outdated assumption LPG will lose you power.
Like all things engine management things have moved on immeasurably in the last few years, & LPG systems have finally caught up delivering very very impressive results.
It's well accepted that (until very recently) you really needed to replace the distributor to get the best performance from LPG.
I say "until very recently" because those still burdened by the distributor can now resolve many of the distributor's disadvantages for less than £200 by fitting something like this:
http://www.aldonamethyst.co.uk/
The Aldon Amethyst gives you back a lot of the control you need to make a half decent job of an LPG conversion for a relatively small outlay, of course to get the best from it you will still need the ignition mapping by someone that properly understands the unique requirements of LPG.
http://questmotorsport.co.uk/
Fuelling is a whole different subject, but essentially the same, by that I mean each fuel type has very different characteristics so will require very different strategies.
The LPG conversion industry get around these ignition & fuelling differences by fitting a second ECU, essentially this second ECU looks at the petrol injector durations & ignition timing and completes a little calculation to correct things for LPG.
This is known as a piggyback system & is what you will always find on every single modern LPG conversion out there, however not all piggyback systems are created equal.
Piggybacks range from the very crude to the extremely sophisticated, the difference typically being the amount of correction that's available to the installer.
I was given a demo of the Prins system, & you would be amazed how clever it is, yet also how simple the software & set up is too.
Select number of cylinders, lambda feedback ect ect & click OK.
Turn the key & it runs, a few very minor tweaks of the vaporiser ect and the mapping is complete, the ECU does the rest.
While this is extremely impressive and makes life incredibly easy for the installer, a piggyback system like this is only as good as the algorithms within & the correction inputs available.
At the end of the day all piggyback ECUs are trying to work with second hand petrol signals that are fundamentally wrong for LPG, it then makes assumptions that if it's "X" on petrol it should be "Y" on LPG.
It's a dumb system if you like, the LPG piggyback isn't looking directly at engine sensor inputs but trying instead to work out what's best for LPG from what essentially is only best for petrol.
As you can see, this is far from ideal.
In the ideal world what you actually need is an ECU that lets you build a unique LPG map based on first hand direct engine sensor inputs, just like you would on petrol.
Of course this does indeed exist in the form of the excellent Emerald system,.... MegaSquirt and many many others.
However, here's the problem....
You can easily get these systems delivering fantastic results on LPG, or petrol....
BUT NOT BOTH....
When you set up one of these stand alone systems you start by telling it the impedance of your injectors, & your petrol injectors will always have a very different impedance to your LPG injectors.
Surprisingly, these stand alone ECU systems do not have the ability to readily fire the petrol injectors on map one & the LPG injectors on map two.
It's a one or the other type deal, which is no good for a dual fuel vehicle, so even if you have an Emerald or similar you are still forced to fit a piggyback ECU
Consequently you are back to twisting second hand petrol signals to try and get the best from LPG.
Enter the Canems Dual Fuel ECU
Canems took the fundamentally flawed operation of the piggyback LPG system, & designed it out.
The Canems DF system for the first time not only allows you to build the perfect fuel & ignition map for petrol, but also allows you to build the perfect map for LPG based on first hand engine sensor inputs, not the second hand petrol information that's completely wrong in the first place.
For the driver it's simple, just flick the changeover switch on the move and you seamlessly switch from your perfected petrol map firing the petrol injectors, to your perfected LPG map firing the LPG injectors.
This sounds like quite a simple thing to design into an ECU, but I'm reliably informed it most certainly isn't.
I'm sure if you approached Phil Ringwood he could do it on a MegaSquirt or Dave Walker for the Emerald.
But as it stands & to my knowledge, the only people that have achieved the dual fuel ECU holly grail in an off the shelf proven package is Canems.
Canems also took the opportunity when designing the dual fuel system to add in other essential LPG specific requirements like LPG solenoid control, this contributes to making the system a much neater & integrated package for anyone looking to move to dual fuel.
The reality is all this is great in theory, but to really explore the potential advantages of the Canems DF ECU will require some extremely skilful mapping, however in practice these skills are no different to those used when mapping on petrol.
But you do need someone who truly understands the different requirements of the two fuels, and more importantly the specific & unique requirements of LPG.
The bottom line is, it doesn't matter how good the Canems DF system is, it doesn't matter how many advantages it seems to offer in theory, if the LPG mapping isn't done well it stands to be no better or worse even than a good piggyback.
As with all these things, the devil is most definitely in the detail
The advance curve will be very different on LPG.
In the simplest terms LPG requires a lot more advance early on, but as engine speed rises the curve will flatten significantly when compared with petrol.
It is of course more complicated than this, as we know the picture is a three dimensional one, strategies will differ between the fuel types under the same RPM, air temperature & load conditions.
Fuel & ignition requirements work hand in hand, alter one & the other will be affected, but it's the different ignition requirements of LPG that are most often the downfall of a lesser conversion.
This is the reason why the ignorant continue to insist LPG will lose you power.
The truth is LPG shouldn't lose you any power whatsoever, this has been proven time & time again & in the real world, modern systems have banished the LPG power loss theory to the history books, FACT!
It's almost always the crude ignition control systems that conversions are often burdened with that are the culprit.
Sadly some people are still reading the old history books and really should update their knowledge on LPG engine management systems before making the outdated assumption LPG will lose you power.
Like all things engine management things have moved on immeasurably in the last few years, & LPG systems have finally caught up delivering very very impressive results.
It's well accepted that (until very recently) you really needed to replace the distributor to get the best performance from LPG.
I say "until very recently" because those still burdened by the distributor can now resolve many of the distributor's disadvantages for less than £200 by fitting something like this:
http://www.aldonamethyst.co.uk/
The Aldon Amethyst gives you back a lot of the control you need to make a half decent job of an LPG conversion for a relatively small outlay, of course to get the best from it you will still need the ignition mapping by someone that properly understands the unique requirements of LPG.
http://questmotorsport.co.uk/
Fuelling is a whole different subject, but essentially the same, by that I mean each fuel type has very different characteristics so will require very different strategies.
The LPG conversion industry get around these ignition & fuelling differences by fitting a second ECU, essentially this second ECU looks at the petrol injector durations & ignition timing and completes a little calculation to correct things for LPG.
This is known as a piggyback system & is what you will always find on every single modern LPG conversion out there, however not all piggyback systems are created equal.
Piggybacks range from the very crude to the extremely sophisticated, the difference typically being the amount of correction that's available to the installer.
I was given a demo of the Prins system, & you would be amazed how clever it is, yet also how simple the software & set up is too.
Select number of cylinders, lambda feedback ect ect & click OK.
Turn the key & it runs, a few very minor tweaks of the vaporiser ect and the mapping is complete, the ECU does the rest.
While this is extremely impressive and makes life incredibly easy for the installer, a piggyback system like this is only as good as the algorithms within & the correction inputs available.
At the end of the day all piggyback ECUs are trying to work with second hand petrol signals that are fundamentally wrong for LPG, it then makes assumptions that if it's "X" on petrol it should be "Y" on LPG.
It's a dumb system if you like, the LPG piggyback isn't looking directly at engine sensor inputs but trying instead to work out what's best for LPG from what essentially is only best for petrol.
As you can see, this is far from ideal.
In the ideal world what you actually need is an ECU that lets you build a unique LPG map based on first hand direct engine sensor inputs, just like you would on petrol.
Of course this does indeed exist in the form of the excellent Emerald system,.... MegaSquirt and many many others.
However, here's the problem....
You can easily get these systems delivering fantastic results on LPG, or petrol....
BUT NOT BOTH....
When you set up one of these stand alone systems you start by telling it the impedance of your injectors, & your petrol injectors will always have a very different impedance to your LPG injectors.
Surprisingly, these stand alone ECU systems do not have the ability to readily fire the petrol injectors on map one & the LPG injectors on map two.
It's a one or the other type deal, which is no good for a dual fuel vehicle, so even if you have an Emerald or similar you are still forced to fit a piggyback ECU
Consequently you are back to twisting second hand petrol signals to try and get the best from LPG.
Enter the Canems Dual Fuel ECU
Canems took the fundamentally flawed operation of the piggyback LPG system, & designed it out.
The Canems DF system for the first time not only allows you to build the perfect fuel & ignition map for petrol, but also allows you to build the perfect map for LPG based on first hand engine sensor inputs, not the second hand petrol information that's completely wrong in the first place.
For the driver it's simple, just flick the changeover switch on the move and you seamlessly switch from your perfected petrol map firing the petrol injectors, to your perfected LPG map firing the LPG injectors.
This sounds like quite a simple thing to design into an ECU, but I'm reliably informed it most certainly isn't.
I'm sure if you approached Phil Ringwood he could do it on a MegaSquirt or Dave Walker for the Emerald.
But as it stands & to my knowledge, the only people that have achieved the dual fuel ECU holly grail in an off the shelf proven package is Canems.
Canems also took the opportunity when designing the dual fuel system to add in other essential LPG specific requirements like LPG solenoid control, this contributes to making the system a much neater & integrated package for anyone looking to move to dual fuel.
The reality is all this is great in theory, but to really explore the potential advantages of the Canems DF ECU will require some extremely skilful mapping, however in practice these skills are no different to those used when mapping on petrol.
But you do need someone who truly understands the different requirements of the two fuels, and more importantly the specific & unique requirements of LPG.
The bottom line is, it doesn't matter how good the Canems DF system is, it doesn't matter how many advantages it seems to offer in theory, if the LPG mapping isn't done well it stands to be no better or worse even than a good piggyback.
As with all these things, the devil is most definitely in the detail
Edited by ChimpOnGas on Monday 4th March 10:54
I am so pleased we live in a free country - then we can have forums like this one and freely express our views and ideas. LPG always has been an interesting question, and clearly still is.
The majority seem to applaud Dave for having the balls to do this and wish him every success with it.
I would no more attempt what Dave has done with his car than take my car's engine completely to pieces and hope that the car would ever work again, but I will be very pleased to see and hear Dave's car running when it is all finished.
By the way, I think Tom Daly is a fantastic diver, but you wouldn't get me on a 10 metre board for love nor money. Same goes for bungee jumping, paragliding, sky diving. Track day? BRING IT ON!!!!! Horses for courses.
The majority seem to applaud Dave for having the balls to do this and wish him every success with it.
I would no more attempt what Dave has done with his car than take my car's engine completely to pieces and hope that the car would ever work again, but I will be very pleased to see and hear Dave's car running when it is all finished.
By the way, I think Tom Daly is a fantastic diver, but you wouldn't get me on a 10 metre board for love nor money. Same goes for bungee jumping, paragliding, sky diving. Track day? BRING IT ON!!!!! Horses for courses.
Nobody, myself included, is "discrediting" your project. Far from it: if you read the whole of my post I give you credit for a really nicely engineered project and I wished you success.
There is no need for this thread to "descend into a pathetic and irrelevant spat", as you put it. My post wasn't pathetic, it wasn't irrelevant, and it is only the start of a "spat" if you choose to respond in the way you have.
I, and others, are simply pointing out that ultimately the success of the project, in cost-benefit terms, hangs entirely on the price of LPG - and that is entirely at the whim of the chancellor. You are, in effect, playing Poker with George Osborne and those who follow him.
And actually, by pointing out the risk that you're taking, I'm doing you a favour. As I say, the fewer people who go down this route, the more successful it'll be for those who do. Do you seriously think that chancellors are going to sit back and watch hordes of people migrate from petrol to LPG without doing something about it?
There is no need for this thread to "descend into a pathetic and irrelevant spat", as you put it. My post wasn't pathetic, it wasn't irrelevant, and it is only the start of a "spat" if you choose to respond in the way you have.
I, and others, are simply pointing out that ultimately the success of the project, in cost-benefit terms, hangs entirely on the price of LPG - and that is entirely at the whim of the chancellor. You are, in effect, playing Poker with George Osborne and those who follow him.
And actually, by pointing out the risk that you're taking, I'm doing you a favour. As I say, the fewer people who go down this route, the more successful it'll be for those who do. Do you seriously think that chancellors are going to sit back and watch hordes of people migrate from petrol to LPG without doing something about it?
Dr Mike Oxgreen said:
Do you seriously think that chancellors are going to sit back and watch hordes of people migrate from petrol to LPG without doing something about it?
And that's just it, hordes of people aren't migrating from petrol to LPG.The truth is since the abolishment of Congestion Charge dispensation for LPG vehicles by the London Mayor Borris Johnson, the picture is quite the opposite.
My own company has now replaced our central London LPG delivery fleet (at the end of their natural life) with diesel Merc Sprinters because of this.
While we were saving £10 a day on every vehicle, LPG made perfect sense, now the LPG dispensation rule has been abolished it's back to giving London kids asthma with our carbon particular rich diesels
The truth is I'm actually more concerned that the recent fall in converted vehicles in the south will alter the economic viability of LPG being offered at a decent enough number of petrol stations.
However, what we do know now for sure is how the Tax Man works, & how he focusses his revenue harvesting energies.
He will look at easy quick wins that deliver high yield gains.
As such I personally very much doubt he will be focussing his efforts on a small niche market like LPG.
You may argue why not, isn't it's easy for him to raise the duty on LPG, and isn't it a case of every little helps?
Well not if that revenue stream dispersals the moment it's been created.
How so?
Here's how so - the typical man on the street who converts his car to LPG does so to save money.
This chap will soon stop filling up with LPG if he sees the price approach petrol, you must remember these conversions are dual fuel, they still run on petrol just like they always did.
So as fast as the Tax Man can stick up the price of LPG, the cost conscious duel fuel user will be hitting the petrol switch and passing the LPG pumps by.
No LPG sales = no additional tax & the whole revenue stream disappears as quickly as it was created.
But the biggest driver is my first point, LPG is still very much a niche market, so the Tax Man isn't really going to be investing his time looking closely at it.
I may be wrong of course, but I prefer to work with this type of evidence that pessimistic speculation, so here's some more evidence.
Historically LPG has always followed the same price differential to petrol, & for years & years, even when there was a small Congestion Charge discount bubble in LPG and conversions became quite popular in and around London, the Tax Man still wasn't interested.
I doubt he'll be interested in it now either as it represents an even smaller prize.
Fast forward five years when we start producing lots of shale gas, this may change, (for the better or worse) but my conversion will have easily paid for itself by then so again I'm not unduly worried.
Finally we need to look at the LPG taxation policies of other countries that have a lot more LPG vehicles on the road than us.
I have recently returned from Brazil, where you have three choices: Alcohol (Ethanol), Petrol or LPG.
Even with the abundance of cheap Ethanol literally millions of taxis still take the the LPG option because it's cheaper, for years each fare they take consistently delivers more profit on LPG than any other fuel.
The price difference remains the same between LPG & Petrol in Brazil as it is in the UK, and that's in a country where a gallon of petrol will cost you less than £4.00 BTW.
The Brazilian Tax Man isn't interested in LPG any more than UK Tax Man is.
It's the same story in France, Germany, Holland, Italy, Denmark ect ect, all countries where LPG is way more popular, and all countries where the price difference has remained static for years & years & years.
Finally, what are we going to do with all this LPG if we don't use a bit of it in our cars?
It's only a by-product of the petrochemical industry anyway.
Perhaps we should go back to 20 years ago when it was simply burnt off at the refinery releasing wasted energy into the atmosphere?
For a multitude of well considered reasons I doubt very much if LPG is going to rocket in price any time soon.
Like I say people have been pedalling this old chestnut in the UK for well over 10 years now as a reason why not to convert, and in all those years it simply never ever happened, here or anywhere else in the world for that matter.
If those considering an LPG conversion had listened to the LPG tax hike doomsayers back then, they'd have missed out on literally thousands of pounds of savings, FACT!
Ok it's always going to be a gamble, I'll give you that, but I believe history and a bit of reasoned logic places the odds in my favour.
Only time will tell.
Edited by ChimpOnGas on Tuesday 5th March 07:39
^^^ Well said Dave - I am more than impressed by your research, factually knowledge and measured, unbiased, informative responses posts throuhgout this thread.
Was given this link over on the Wedge forum - is this LPG commentary now out of date do you think?
http://www.mez.co.uk/TuningTheRoverV8-pt7.html
I did a 200 mile round trip at the week-end in the Griff and used £25 worth of fuel with still 1/3 of a tank left.. as you say "what's not to like"...
Keep up the good work and look forward to comparing notes when you are up and running.
Paul.
Was given this link over on the Wedge forum - is this LPG commentary now out of date do you think?
http://www.mez.co.uk/TuningTheRoverV8-pt7.html
I did a 200 mile round trip at the week-end in the Griff and used £25 worth of fuel with still 1/3 of a tank left.. as you say "what's not to like"...
Keep up the good work and look forward to comparing notes when you are up and running.
Paul.
pjac67 said:
^^^ Well said Dave - I am more than impressed by your research, factually knowledge and measured, unbiased, informative responses posts throuhgout this thread.
Was given this link over on the Wedge forum - is this LPG commentary now out of date do you think?
http://www.mez.co.uk/TuningTheRoverV8-pt7.html
I did a 200 mile round trip at the week-end in the Griff and used £25 worth of fuel with still 1/3 of a tank left.. as you say "what's not to like"...
Keep up the good work and look forward to comparing notes when you are up and running.
Paul.
Hi Paul, thanks for giving us those figures, its great to hear some real world results from an existing TVR LPG user.Was given this link over on the Wedge forum - is this LPG commentary now out of date do you think?
http://www.mez.co.uk/TuningTheRoverV8-pt7.html
I did a 200 mile round trip at the week-end in the Griff and used £25 worth of fuel with still 1/3 of a tank left.. as you say "what's not to like"...
Keep up the good work and look forward to comparing notes when you are up and running.
Paul.
If you did 200 miles on £25 & I've got my maths right, you're seeing a real world 27mpg.
That's a good figure for these cars on petrol, never mind LPG that should by rights reduce direct fuel economy by 15%.
I believe you are running an Emerald ECU which is still one of the best & easiest to work with engine management systems available.
It's also giving you proper mapped ignition, which is essential if you want decent LPG economy & no loss of performance.
Clearly it's set up extremely well & the piggyback ECU is a good one doing an excellent job.
Lets look at that 27mpg figure again for a minute.
I use the 0.55 multiplier, you can check it works like this:
Petrol @ £1.35 litre x 0.55 = LPG at £0.75 per litre
So at a real world LPG consumption of 27mpg it looks like this:
27mpg x 0.55 = 14.85
14.85 + 27 = 41.85
Please feel free to correct my maths if its wrong, but from what I can see thats a truly excellent cost equivalent of 41.85mpg
I dont know what fuel economy you were getting on petrol in your Griff but knowing these cars typical fuel economy figures, it looks unlikely your losing much if any economy on LPG, let alone the much touted 15%.
If that's correct I speculate you would have spent £45.00 on petrol to cover those same 200 miles, so you've just saved £20.00 in only 200 miles, or put another way, £0.10p saved for every mile you drive the car.
Lets say your conversion cost you £1500, at £0.10p a mile saved it will have paid for itself in just 15,000 miles.
Assuming the tax man doesn't stick the duty up, even if you're only do 5,000 miles a year the conversion has paid for itself within only 3 years.
Or just 18 months if you do 10,000 miles a year
After that you are laughing all the way to the bank & driving an epic TVR Griffith that returns Ford Focus fuel economy.
Congratulations Paul, I call that a truly amazing result.
On the other hand if you take a litre price of petrol at £1.35 then times it by 1.80 you get the true LPG price of £0.75p a litre.
And having been following pump prices for a while now, these seem to be the correct average real world pump prices of both fuels.
If we use the 1.80 multiplier with Paul's figures it actually looks like this:
27mpg x 1.80 = 48.6
So Paul is actually seeing a mind bending cost equivalent of...
48.6 mpg
That conversion will pay for itself in no time mate
Edited by ChimpOnGas on Monday 4th March 16:20
Not sure of the maths there Dave? - I fill up at 69p (soon to be 64p when I get my Countrywide a/c) so my 200/£25 is 25mpg (was a boring motorway/A road procession - I normally average closer to 20 when 'hooning' 
)
This is equivalent to 49 mpg assuming equivalent MPG (or knock 10% off if you wish to assume some MPG loss = 45 mpg equiv.)
The saving of 66p/litre means my £1400 system payback is within 2121 litres /466 gallons x 20 mpg av. = 9323miles which will be 18m for my 6k+ pa...
Does this look right or is there a flaw in my maths..?
)This is equivalent to 49 mpg assuming equivalent MPG (or knock 10% off if you wish to assume some MPG loss = 45 mpg equiv.)
The saving of 66p/litre means my £1400 system payback is within 2121 litres /466 gallons x 20 mpg av. = 9323miles which will be 18m for my 6k+ pa...
Does this look right or is there a flaw in my maths..?
Edited by pjac67 on Monday 4th March 16:59
Really interesting thread. My Dad converted a Range Rover p38 back in 2000, and ran that for about 5 years.
For that time he had his own bulk tank at home, the convenience of which sticks with me, having removed the spare wheel well and with bespoke tanks fitted he had approx 300 miles range.
Thus he rarely filled up anywhere but home.
For that time he had his own bulk tank at home, the convenience of which sticks with me, having removed the spare wheel well and with bespoke tanks fitted he had approx 300 miles range.
Thus he rarely filled up anywhere but home.
pjac67 said:
Not sure of the maths there Dave - I fill up at 69p (soon to be 64p when I get my ountrywide a/c) so my 200/£25 is 25mpg (was a boring motorway/A road procession - I normally average closer to 20 when 'hooning' )
This is equivalent to 49 mpg assuming no equivalent MPG (or knock 10% off if you wish to assume some MPG loss = 45 mpg equiv.
The saving of 66p/litre means my £1400 system payback is within 2121 litres /466 gallons x 20 mpg av. = 9323miles which will be 18m for my 6k+ pa...
Does this look right or is there a flaw in my maths..?
Nice one Paul, your maths are indeed better than mine. )This is equivalent to 49 mpg assuming no equivalent MPG (or knock 10% off if you wish to assume some MPG loss = 45 mpg equiv.
The saving of 66p/litre means my £1400 system payback is within 2121 litres /466 gallons x 20 mpg av. = 9323miles which will be 18m for my 6k+ pa...
Does this look right or is there a flaw in my maths..?
I assumed an LPG price of £0.75p a litre, but I do live inside the M25 and we get ripped off on everything here.
Your price of £0.69p a litre is excellent, and £0.64 is amazing.
Your cost equivalent of 45mpg is what I'm aiming for with my baby 4.0 litre on the expensive stuff I will be buying.
Mind you, I do find it mildly amusing I'm referring to £0.75p a litre as expensive
I looked at getting a Countrywide acc but they mostly seem to be in the more rural areas, which I guess makes sense for the type of business they are.
My nearest Countrywide fill point is 30 miles away in Surrey, I'd really need one closer to home that that to make an account worthwhile
I do however have three LPG stations on my doorstep, BP that robs you at £0.78p a litre, while Sainsburys serves up the gas at £0.75 a litre.
So you are doing very well indeed with those prices mate, or more likely I'm just getting mugged again
The third option is as yet un-tested, it's a boat yard at the bottom of my street that advertise as selling Auto Gas.
I may just walk down there now & see what price they sell at.
GasMunkey said:
Am I the only one flicking through just for the pictures?
Dave not quite sure what's happened on this post or if some of the posts have been deleted? I didn't get the impression that Dr Oxgreen was sending you up so I am slightly 
has I have said already I have no intention of ever going LPG but I still find this post interesting same as the others & look forward to seeing the old girl running on the stuff 
Sardonicus said:
Dave not quite sure what's happened on this post or if some of the posts have been deleted? I didn't get the impression that Dr Oxgreen was sending you up so I am slightly has I have said already I have no intention of ever going LPG but I still find this post interesting same as the others & look forward to seeing the old girl running on the stuff Dr Oxgreen was actually just opening the debate wider, it wasn't the direct challenge I first thought it was at all.
I guess it's the way I read things sometimes, God knows Ribol & I have had some similar banter in the past
Apologies to Dr Oxgreen, I will try and read your responses better in future.
Actually from what I can see you are enjoying the debate & are interested in the project, if you really unpick it there are actually elements we agree on too.
I'll try & wind my arrogant neck in
Best regards, Dave.
chimpongas
just got the heads up from zig, good to see someone else taking this route, my wedge has only got a 55ltr tank ( as not designed for golf clubs and hairdressers bags )and the auto stop works at 80% that gives me about 46ltrs i get around 210-220 miles and that is usually spirited,that gives me around 21-22 mpg if on a long run i can get up to 25-26mpg. Its a bog standard 350i with flapper system, the gas is a sequential injection set up. The filler is hidden behind the number plate it hinges down for access neat as can`t be seen and can fill up from either side of the dispenser. The routing of the feed pipe from the tanks can be a pain too route to get the req 250mm from the exhaust otherwise heat shields all over the place. I like your idea of the 2 tanks 1 on top of the other, the fill line should have built in back check valves in the tee to prevent flow of gas from 1 tank too the other, but if you use a standard tee without back checks and doctor the auto stop on the bottom tank so the gas can flow between the tanks and leave the top autostop as standard you will retain some ullage space on the top tank that would give 54ltrs gas capacity almost 12 gallons @25mpg =300miles. Lpg prices dont worry me too much as i have used it for over 25 years and it has always been around half bat, currently the duty rate is about 18p per ltr so there is along way to go before it catches up with petrol and diesel.
just got the heads up from zig, good to see someone else taking this route, my wedge has only got a 55ltr tank ( as not designed for golf clubs and hairdressers bags )and the auto stop works at 80% that gives me about 46ltrs i get around 210-220 miles and that is usually spirited,that gives me around 21-22 mpg if on a long run i can get up to 25-26mpg. Its a bog standard 350i with flapper system, the gas is a sequential injection set up. The filler is hidden behind the number plate it hinges down for access neat as can`t be seen and can fill up from either side of the dispenser. The routing of the feed pipe from the tanks can be a pain too route to get the req 250mm from the exhaust otherwise heat shields all over the place. I like your idea of the 2 tanks 1 on top of the other, the fill line should have built in back check valves in the tee to prevent flow of gas from 1 tank too the other, but if you use a standard tee without back checks and doctor the auto stop on the bottom tank so the gas can flow between the tanks and leave the top autostop as standard you will retain some ullage space on the top tank that would give 54ltrs gas capacity almost 12 gallons @25mpg =300miles. Lpg prices dont worry me too much as i have used it for over 25 years and it has always been around half bat, currently the duty rate is about 18p per ltr so there is along way to go before it catches up with petrol and diesel.
gas wedge said:
chimpongas
just got the heads up from zig, good to see someone else taking this route, my wedge has only got a 55ltr tank ( as not designed for golf clubs and hairdressers bags )and the auto stop works at 80% that gives me about 46ltrs i get around 210-220 miles and that is usually spirited,that gives me around 21-22 mpg if on a long run i can get up to 25-26mpg. Its a bog standard 350i with flapper system, the gas is a sequential injection set up. The filler is hidden behind the number plate it hinges down for access neat as can`t be seen and can fill up from either side of the dispenser. The routing of the feed pipe from the tanks can be a pain too route to get the req 250mm from the exhaust otherwise heat shields all over the place. I like your idea of the 2 tanks 1 on top of the other, the fill line should have built in back check valves in the tee to prevent flow of gas from 1 tank too the other, but if you use a standard tee without back checks and doctor the auto stop on the bottom tank so the gas can flow between the tanks and leave the top autostop as standard you will retain some ullage space on the top tank that would give 54ltrs gas capacity almost 12 gallons @25mpg =300miles. Lpg prices dont worry me too much as i have used it for over 25 years and it has always been around half bat, currently the duty rate is about 18p per ltr so there is along way to go before it catches up with petrol and diesel.
Excellent John, in some ways you were my early inspiration for an LPG TVR.just got the heads up from zig, good to see someone else taking this route, my wedge has only got a 55ltr tank ( as not designed for golf clubs and hairdressers bags )and the auto stop works at 80% that gives me about 46ltrs i get around 210-220 miles and that is usually spirited,that gives me around 21-22 mpg if on a long run i can get up to 25-26mpg. Its a bog standard 350i with flapper system, the gas is a sequential injection set up. The filler is hidden behind the number plate it hinges down for access neat as can`t be seen and can fill up from either side of the dispenser. The routing of the feed pipe from the tanks can be a pain too route to get the req 250mm from the exhaust otherwise heat shields all over the place. I like your idea of the 2 tanks 1 on top of the other, the fill line should have built in back check valves in the tee to prevent flow of gas from 1 tank too the other, but if you use a standard tee without back checks and doctor the auto stop on the bottom tank so the gas can flow between the tanks and leave the top autostop as standard you will retain some ullage space on the top tank that would give 54ltrs gas capacity almost 12 gallons @25mpg =300miles. Lpg prices dont worry me too much as i have used it for over 25 years and it has always been around half bat, currently the duty rate is about 18p per ltr so there is along way to go before it catches up with petrol and diesel.
It seems you've been enjoying the benefits of gas for many years now, so I really value your input.
Hopefully I'll see you at the BBWF this year?
My boot still has plenty of space left even with the LPG, so I'll make sure I bring my golf bats
And yes.... even with the roof off
Chipmongas can you recommend a good Piggy back system ? I know there is alot of Polsih c
p on the market .
Read through one of your posts above ,you mentioned low and high impedance injectors !there must be LPG injectors to match petrol on`s on the market .Would that do the trick on the "stand alone" ECU.
Will your TVR be excempt from the congestion charge ?
p on the market .Read through one of your posts above ,you mentioned low and high impedance injectors !there must be LPG injectors to match petrol on`s on the market .Would that do the trick on the "stand alone" ECU.
Will your TVR be excempt from the congestion charge ?
SILICONEKID350HP said:
Chipmongas can you recommend a good Piggy back system ? I know there is alot of Polsih cp on the market .
Read through one of your posts above ,you mentioned low and high impedance injectors !there must be LPG injectors to match petrol on`s on the market .Would that do the trick on the "stand alone" ECU.
Will your TVR be excempt from the congestion charge ?
The Prins system from the Netherlands is widely regarded as the best.p on the market .Read through one of your posts above ,you mentioned low and high impedance injectors !there must be LPG injectors to match petrol on`s on the market .Would that do the trick on the "stand alone" ECU.
Will your TVR be excempt from the congestion charge ?
But what you really need Daz, is someone that understands MegaSquirt who's also an LPG expert.
How about having a chat with the LPG chap that fitted your MegaSquirt?
ChimpOnGas said:
gas wedge said:
chimpongas
just got the heads up from zig, good to see someone else taking this route, my wedge has only got a 55ltr tank ( as not designed for golf clubs and hairdressers bags )and the auto stop works at 80% that gives me about 46ltrs i get around 210-220 miles and that is usually spirited,that gives me around 21-22 mpg if on a long run i can get up to 25-26mpg. Its a bog standard 350i with flapper system, the gas is a sequential injection set up. The filler is hidden behind the number plate it hinges down for access neat as can`t be seen and can fill up from either side of the dispenser. The routing of the feed pipe from the tanks can be a pain too route to get the req 250mm from the exhaust otherwise heat shields all over the place. I like your idea of the 2 tanks 1 on top of the other, the fill line should have built in back check valves in the tee to prevent flow of gas from 1 tank too the other, but if you use a standard tee without back checks and doctor the auto stop on the bottom tank so the gas can flow between the tanks and leave the top autostop as standard you will retain some ullage space on the top tank that would give 54ltrs gas capacity almost 12 gallons @25mpg =300miles. Lpg prices dont worry me too much as i have used it for over 25 years and it has always been around half bat, currently the duty rate is about 18p per ltr so there is along way to go before it catches up with petrol and diesel.
Excellent John, in some ways you were my early inspiration for an LPG TVR.just got the heads up from zig, good to see someone else taking this route, my wedge has only got a 55ltr tank ( as not designed for golf clubs and hairdressers bags )and the auto stop works at 80% that gives me about 46ltrs i get around 210-220 miles and that is usually spirited,that gives me around 21-22 mpg if on a long run i can get up to 25-26mpg. Its a bog standard 350i with flapper system, the gas is a sequential injection set up. The filler is hidden behind the number plate it hinges down for access neat as can`t be seen and can fill up from either side of the dispenser. The routing of the feed pipe from the tanks can be a pain too route to get the req 250mm from the exhaust otherwise heat shields all over the place. I like your idea of the 2 tanks 1 on top of the other, the fill line should have built in back check valves in the tee to prevent flow of gas from 1 tank too the other, but if you use a standard tee without back checks and doctor the auto stop on the bottom tank so the gas can flow between the tanks and leave the top autostop as standard you will retain some ullage space on the top tank that would give 54ltrs gas capacity almost 12 gallons @25mpg =300miles. Lpg prices dont worry me too much as i have used it for over 25 years and it has always been around half bat, currently the duty rate is about 18p per ltr so there is along way to go before it catches up with petrol and diesel.
It seems you've been enjoying the benefits of gas for many years now, so I really value your input.
Hopefully I'll see you at the BBWF this year?
My boot still has plenty of space left even with the LPG, so I'll make sure I bring my golf bats
And yes.... even with the roof off
ChimpOnGas said:
SILICONEKID350HP said:
Chipmongas can you recommend a good Piggy back system ? I know there is alot of Polsih cp on the market .
Read through one of your posts above ,you mentioned low and high impedance injectors !there must be LPG injectors to match petrol on`s on the market .Would that do the trick on the "stand alone" ECU.
Will your TVR be excempt from the congestion charge ?
The Prins system from the Netherlands is widely regarded as the best.p on the market .Read through one of your posts above ,you mentioned low and high impedance injectors !there must be LPG injectors to match petrol on`s on the market .Would that do the trick on the "stand alone" ECU.
Will your TVR be excempt from the congestion charge ?
But what you really need Daz, is someone that understands MegaSquirt who's also an LPG expert.
How about having a chat with the LPG chap that fitted your MegaSquirt?
Edited by SILICONEKID350HP on Monday 4th March 22:50
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