LPG Chimaera (Follow My Conversion)
Discussion
Ok, so the latest development is complete in the form of two new ECU inputs.
1. Gas pressure
2. Gas temperature
The theory is being a gaseous fuel rather than a liquid it's volume changes much more than petrol over a much narrower range of temps, this in turn has a far greater impact on air fuel ratios.
We have already learned these fluctuations in AFRs can be managed effectively using a targeted close loop strategy, this being a post combustion correction process we wanted to see if adding a pre combustion strategy could help deliver even more consistent AFRs?
The idea is to measure the pressure using a manifold absolute pressure sensor after the vaporiser but before the injectors, along with a temperature sensor for good measure.
David Hampshire very kindly added the inputs and created an addition to the software that included two separate correction tables. A Prins filter assembly was then fitted to the car that houses a special Bosch LPG sensor reading both pressure & temp.
The new features were added in the form of a new exchange dual fuel ECU as it made sense to do things this way, it also allowed for various other additions and software updates in line with the Canems policy of continual development of their excellent products.
The whole package was fitted and then carefully mapped by Lloyd Specialist Developments, the first part of the mapping process being to log the fluctuations in LPG pressure & temperature to see what was really happening post vaparisor.
The results are quite interesting and in many ways somewhat unexpected.
1. Gas pressure
2. Gas temperature
The theory is being a gaseous fuel rather than a liquid it's volume changes much more than petrol over a much narrower range of temps, this in turn has a far greater impact on air fuel ratios.
We have already learned these fluctuations in AFRs can be managed effectively using a targeted close loop strategy, this being a post combustion correction process we wanted to see if adding a pre combustion strategy could help deliver even more consistent AFRs?
The idea is to measure the pressure using a manifold absolute pressure sensor after the vaporiser but before the injectors, along with a temperature sensor for good measure.
David Hampshire very kindly added the inputs and created an addition to the software that included two separate correction tables. A Prins filter assembly was then fitted to the car that houses a special Bosch LPG sensor reading both pressure & temp.
The new features were added in the form of a new exchange dual fuel ECU as it made sense to do things this way, it also allowed for various other additions and software updates in line with the Canems policy of continual development of their excellent products.
The whole package was fitted and then carefully mapped by Lloyd Specialist Developments, the first part of the mapping process being to log the fluctuations in LPG pressure & temperature to see what was really happening post vaparisor.
The results are quite interesting and in many ways somewhat unexpected.
Edited by ChimpOnGas on Sunday 15th March 23:52
The vapouriser on my Jeep was playing up a few weeks back, basically not getting hot enough to do the job..... The liquid gas that got through, buggered up a full set of injectors, and caused emission lights and loads of error codes....
New injectors...and new vapouriser, and all is good
New injectors...and new vapouriser, and all is good
ChimpOnGas said:
Ok, so the latest development is complete in the form of two new ECU inputs.
1. Gas pressure
2. Gas temperature
The theory is being a gasseus fuel rather than a liquid it's volume changes much more tha petrol over a much narrower range of temps, this in turn has a far greater impact on air fuel ratios.
We have already learned these fluctuations in AFRs can be managed effectively using a targeted close loop strategy, this being a post combustion correction process, but we wanted to see if adding a pre combustion strategy could help deliver even more consistent AFRs?
The idea is to measure the pressure using a manifold absolute pressure sensor after the vaporiser but before the injectors along with a temperature sensor for good measure.
David Hampshire very kindly added the inputs and created an addition to the software that included two separate correction tables. A Prints filter assembly was the fitted to the car as this houses a special Bosch LPG sensor that gives pressure & temp.
The new features were added in the form of a new exchange dual fuel ECU as it made sense to do things this way, it also allowed for various other addition s and software updated in line with the Canems policy of continual development of their products.
The whole package was fitted and then carefully mapped by Lloyd Specialist Developments, the first part of the mapping process being to log the fluctuations in LPG pressure & temperature to see what was really happening post vaparisor.
The results are quite interesting and in many ways somewhat unexpected.
Now your moving into the realms of complexity Dave the costs must be going up exponentially now if not for the sum of parts but labour, not a pop just an observation 1. Gas pressure
2. Gas temperature
The theory is being a gasseus fuel rather than a liquid it's volume changes much more tha petrol over a much narrower range of temps, this in turn has a far greater impact on air fuel ratios.
We have already learned these fluctuations in AFRs can be managed effectively using a targeted close loop strategy, this being a post combustion correction process, but we wanted to see if adding a pre combustion strategy could help deliver even more consistent AFRs?
The idea is to measure the pressure using a manifold absolute pressure sensor after the vaporiser but before the injectors along with a temperature sensor for good measure.
David Hampshire very kindly added the inputs and created an addition to the software that included two separate correction tables. A Prints filter assembly was the fitted to the car as this houses a special Bosch LPG sensor that gives pressure & temp.
The new features were added in the form of a new exchange dual fuel ECU as it made sense to do things this way, it also allowed for various other addition s and software updated in line with the Canems policy of continual development of their products.
The whole package was fitted and then carefully mapped by Lloyd Specialist Developments, the first part of the mapping process being to log the fluctuations in LPG pressure & temperature to see what was really happening post vaparisor.
The results are quite interesting and in many ways somewhat unexpected.
Edited by ChimpOnGas on Sunday 15th March 21:48
its clever stuff though 
ChimpOnGas said:
Ok, so the latest development is complete in the form of two new ECU inputs.
1. Gas pressure
2. Gas temperature
The theory is being a gasseus fuel rather than a liquid it's volume changes much more tha petrol over a much narrower range of temps, this in turn has a far greater impact on air fuel ratios.
We have already learned these fluctuations in AFRs can be managed effectively using a targeted close loop strategy, this being a post combustion correction process, but we wanted to see if adding a pre combustion strategy could help deliver even more consistent AFRs?
The idea is to measure the pressure using a manifold absolute pressure sensor after the vaporiser but before the injectors along with a temperature sensor for good measure.
David Hampshire very kindly added the inputs and created an addition to the software that included two separate correction tables. A Prints filter assembly was the fitted to the car as this houses a special Bosch LPG sensor that gives pressure & temp.
The new features were added in the form of a new exchange dual fuel ECU as it made sense to do things this way, it also allowed for various other addition s and software updated in line with the Canems policy of continual development of their products.
The whole package was fitted and then carefully mapped by Lloyd Specialist Developments, the first part of the mapping process being to log the fluctuations in LPG pressure & temperature to see what was really happening post vaparisor.
The results are quite interesting and in many ways somewhat unexpected.
Take my hat off to you ,will you be looking at saving one or maybe two mpg ?1. Gas pressure
2. Gas temperature
The theory is being a gasseus fuel rather than a liquid it's volume changes much more tha petrol over a much narrower range of temps, this in turn has a far greater impact on air fuel ratios.
We have already learned these fluctuations in AFRs can be managed effectively using a targeted close loop strategy, this being a post combustion correction process, but we wanted to see if adding a pre combustion strategy could help deliver even more consistent AFRs?
The idea is to measure the pressure using a manifold absolute pressure sensor after the vaporiser but before the injectors along with a temperature sensor for good measure.
David Hampshire very kindly added the inputs and created an addition to the software that included two separate correction tables. A Prints filter assembly was the fitted to the car as this houses a special Bosch LPG sensor that gives pressure & temp.
The new features were added in the form of a new exchange dual fuel ECU as it made sense to do things this way, it also allowed for various other addition s and software updated in line with the Canems policy of continual development of their products.
The whole package was fitted and then carefully mapped by Lloyd Specialist Developments, the first part of the mapping process being to log the fluctuations in LPG pressure & temperature to see what was really happening post vaparisor.
The results are quite interesting and in many ways somewhat unexpected.
Edited by ChimpOnGas on Sunday 15th March 21:48
SILICONEKID345HP said:
Take my hat off to you ,will you be looking at saving one or maybe two mpg ?
I know you'll struggle to get your head around this Daz, but it's not about saving one or two MPGs.It's about about learning the fuel, it's all about research; there are no specific targets to the development other than improving our knowledge.
Like all research it starts by recording data to understand what's really going on, for this I needed sensors & additional ECU inputs, I also needed some further additions to the already very clever software.
What we are doing here is studying the unique behavior of a gaseous fuel, what we are not doing is guessing.
Only once the behaviors are fully understood can we look to deploy the new strategies to alter injector durations to compensate for swings & inconsistencies in AFRs we have observed from the outset, but only if there's a proven benefit in doing so.
To be honest closed loop nails it already, but that doesn't mean we stop the learning & developing process there, it also doesn't mean we stop trying to make things even better than they are already.
I fully appreciate people struggle to understand my obsession with this fuel, and even more so when I openly reveal it's not a cost driven exercise. The truth is I just like learning things and I particularly like applying logic to solve a problem or make something better.
If Thomas Edison listened to all the people who kept pointing out he could have bought a lifetime supply of candles for the cost of all his lab equipment, he would have never developed the light bulb.
I'm not suggesting we're breaking serious new ground here, indeed much of what I'm learning is already well understood, the thing is it's a hobby for me and LPG has and always will be a fuel that fascinates me.
It's cheap, super clean burning, very high octane, and most importantly available virtually everywhere.
I've driven a lot of LPG cars that are an extremely disappointing experience, I've also driven one or two that are what I would class as acceptable, but I've never driven one that that actually drives better on gas than petrol.
A "cake & eat it" LPG performance car that drives better, makes more power & torque on gas than petrol has always been my goal.
To that end I've already achieved most of my objectives, but that doesn't stop me wanting more, and it certainly doesn't stop the process of ongoing development.
I know I'm a bit weird, but I can't believe I'm the only one that thinks like this
Now that I've sorted the Hemi....I have to say, I honestly can't tell the difference between LPG and petrol... I've fitted and had set up a new 450bhp rated vapouriser, (the old one was 350bhp) and its spot on, no longer switches back to petrol on kick down, and is doing more to the gallon than it's ever done...
ChimpOnGas said:
I know you'll struggle to get your head around this Daz, but it's not about saving one or two MPGs.
It's about about learning the fuel, it's all about research; there are no specific targets to the development other than improving our knowledge.
Like all research it starts by recording data to understand what's really going on, for this I needed sensors & additional ECU inputs, I also needed some further additions to the already very clever software.
What we are doing here is studying the unique behavior of a gaseous fuel, what we are not doing is guessing.
Only once the behaviors are fully understood can we look to deploy the new strategies to alter injector durations to compensate for swings & inconsistencies in AFRs we have observed from the outset, but only if there's a proven benefit in doing so.
To be honest closed loop nails it already, but that doesn't mean we stop the learning & developing process there, it also doesn't mean we stop trying to make things even better than they are already.
I fully appreciate people struggle to understand my obsession with this fuel, and even more so when I openly reveal it's not a cost driven exercise. The truth is I just like learning things and I particularly like applying logic to solve a problem or make something better.
If Thomas Edison listened to all the people who kept pointing out he could have bought a lifetime supply of candles for the cost of all his lab equipment, he would have never developed the light bulb.
I'm not suggesting we're breaking serious new ground here, indeed much of what I'm learning is already well understood, the thing is it's a hobby for me and LPG has and always will be a fuel that fascinates me.
It's cheap, super clean burning, very high octane, and most importantly available virtually everywhere.
I've driven a lot of LPG cars that are an extremely disappointing experience, I've also driven one or two that are what I would class as acceptable, but I've never driven one that that actually drives better on gas than petrol.
A "cake & eat it" LPG performance car that drives better, makes more power & torque on gas than petrol has always been my goal.
To that end I've already achieved most of my objectives, but that doesn't stop me wanting more, and it certainly doesn't stop the process of ongoing development.
I know I'm a bit weird, but I can't believe I'm the only one that thinks like this
It must of been done already by car manufactures ,they spend millions on development .It's about about learning the fuel, it's all about research; there are no specific targets to the development other than improving our knowledge.
Like all research it starts by recording data to understand what's really going on, for this I needed sensors & additional ECU inputs, I also needed some further additions to the already very clever software.
What we are doing here is studying the unique behavior of a gaseous fuel, what we are not doing is guessing.
Only once the behaviors are fully understood can we look to deploy the new strategies to alter injector durations to compensate for swings & inconsistencies in AFRs we have observed from the outset, but only if there's a proven benefit in doing so.
To be honest closed loop nails it already, but that doesn't mean we stop the learning & developing process there, it also doesn't mean we stop trying to make things even better than they are already.
I fully appreciate people struggle to understand my obsession with this fuel, and even more so when I openly reveal it's not a cost driven exercise. The truth is I just like learning things and I particularly like applying logic to solve a problem or make something better.
If Thomas Edison listened to all the people who kept pointing out he could have bought a lifetime supply of candles for the cost of all his lab equipment, he would have never developed the light bulb.
I'm not suggesting we're breaking serious new ground here, indeed much of what I'm learning is already well understood, the thing is it's a hobby for me and LPG has and always will be a fuel that fascinates me.
It's cheap, super clean burning, very high octane, and most importantly available virtually everywhere.
I've driven a lot of LPG cars that are an extremely disappointing experience, I've also driven one or two that are what I would class as acceptable, but I've never driven one that that actually drives better on gas than petrol.
A "cake & eat it" LPG performance car that drives better, makes more power & torque on gas than petrol has always been my goal.
To that end I've already achieved most of my objectives, but that doesn't stop me wanting more, and it certainly doesn't stop the process of ongoing development.
I know I'm a bit weird, but I can't believe I'm the only one that thinks like this
Quinny said:
The vapouriser on my Jeep was playing up a few weeks back, basically not getting hot enough to do the job..... The liquid gas that got through, buggered up a full set of injectors, and caused emission lights and loads of error codes....
New injectors...and new vapouriser, and all is good
Thats a common one Quinny.New injectors...and new vapouriser, and all is good
The solution to consistent vapariser temperatures is to improve the circulation of coolant through the vapariser's water jacket.
And here's how.
http://www.daviescraig.com.au/Images/Categories/EW...
All you need is the little EBP model (Electric Booster Pump), no bigger than a tennis ball this tiny pump is designed to assist the mechanical water pump, not replace it.
http://www.jjcraceandrally.com/race/electric-water...
During winter months the constant cold ambient temperatures can be sufficient to drag the vaporiser's temperature below an acceptable level, remember, a mechanical water pump is not a positive displacement pump, it is just a paddle to promote flow and assist the natural process of thermosyphon.
Use this little pump to keep the coolant moving through the vaporiser in a more consistent way and you should never have the same problem again.
I also recommend the use of thermostatically controlled injector heaters, these will keep your LPG injectors at the correct temperature and help control the accumulation of heavy end propane deposits that kills gas injectors.
http://www.ebay.co.uk/itm/LPG-INJECTOR-RAIL-HEATER...
You can buy two injector rail heaters and the Davies Craig EBP for around £130 all in, this is cheaper than buying new injectors and a vaporiser.
Keep in mind, if you don't invest in a solution the problem will come back one day.
Hope this helps, Dave.
Quinny said:
Now that I've sorted the Hemi....I have to say, I honestly can't tell the difference between LPG and petrol... I've fitted and had set up a new 450bhp rated vapouriser, (the old one was 350bhp) and its spot on, no longer switches back to petrol on kick down, and is doing more to the gallon than it's ever done...
KME Twin Quinny?
http://www.lpgshop.co.uk/kme-twin-410hp-reducer-in...
What injectors are you running?
SILICONEKID345HP said:
It must of been done already by car manufactures ,they spend millions on development .
Quite right, the people that really understand the behavior of LPG are companies like Prins & LPG Tech.They have research & development departments I would die for, they also have vast knowledge of this fuel that I'd love to tap into.
What I have is an inquisitive mind, David Hampshire of Canems Engine Management Systems, and the boys as Lloyd Specialist Developments.
Actually I was only thinking today as I pulled a gas powered 138 leptons on the M11....
"it's a team that works quite well"
ChimpOnGas said:
KME Twin Quinny?
http://www.lpgshop.co.uk/kme-twin-410hp-reducer-in...
What injectors are you running?
The old unit was rated at 350 if you used both outlets.... And it used to struggle at high RPM
New unit is rated at 450 with both outlets, and seems much more suited....
Injectors are also magic.....drilled out to 3mm...again I just swapped like for like, as all wiring and fittings are already there..
Not the best kit around, but it is sequential, and it was what came with the car
My older jeep is running OMVL And that seems to be better kit
ChimpOnGas said:
I also recommend the use of thermostatically controlled injector heaters, these will keep your LPG injectors at the correct temperature and help control the accumulation of heavy end propane deposits that kills gas injectors.
http://www.ebay.co.uk/itm/LPG-INJECTOR-RAIL-HEATER...
I use 2 of the above on my 6 cylinder BMW X5 and they work really well. I was looking for a while for something like this and this is the only one that I found, I would have thought more people would be making them.http://www.ebay.co.uk/itm/LPG-INJECTOR-RAIL-HEATER...
Despite being told the Government will pull the tax benefits on LPG.
Despite Daz telling me LPG is getting more expensive.
Actually the exact opposite is true..
Running on gas is getting cheaper and cheaper
It's all in the cost differential between the price of the two fuels at the same station on the same day
Despite Daz telling me LPG is getting more expensive.
Actually the exact opposite is true..
Running on gas is getting cheaper and cheaper
It's all in the cost differential between the price of the two fuels at the same station on the same day
- October 2014: Petrol @ 1.24 per litre / LPG @ 0.68 per litre = 1.823 x 23.2mpg = a petrol cost equivalent of 42.3mpg
- January 2015: Petrol @ 1.057 per litre / LPG @ 0.547 per litre = 1.932 x 23.2mpg = a petrol cost equivalent of 44.83mpg
- July 2015: Petrol @ 1.159 per litre / LPG @ 0.559 per litre = 2.0733 x 23.2mpg = a petrol cost equivalent of 48.10mpg
As part of the continual 'Ol Gasbag' development program I received these little beauties in the post today..
In theory these Hana Golds will support up to 400hp as a set of eight
Famed as the very best 1.9 Ohm LPG injectors in the world, Hana Golds are also lovely looking things to my eyes
Roll on phase three of project 'Ol Gasbag'..
In theory these Hana Golds will support up to 400hp as a set of eight
Famed as the very best 1.9 Ohm LPG injectors in the world, Hana Golds are also lovely looking things to my eyes
Roll on phase three of project 'Ol Gasbag'..
ChimpOnGas said:
As part of the continual 'Ol Gasbag' development program I received these little beauties in the post today..
In theory these Hana Golds will support up to 400hp as a set of eight
Famed as the very best 1.9 Ohm LPG injectors in the world, Hana Golds are also lovely looking things to my eyes
Roll on phase three of project 'Ol Gasbag'..
Bloody hell Dave they are low impedance In theory these Hana Golds will support up to 400hp as a set of eight
Famed as the very best 1.9 Ohm LPG injectors in the world, Hana Golds are also lovely looking things to my eyes
Roll on phase three of project 'Ol Gasbag'..
still cant be to surprised with the volume they need to shift Sardonicus said:
loody hell Dave they are low impedance still cant be to surprised with the volume they need to shift
Peak..and hold, dont forget Simon. still cant be to surprised with the volume they need to shift As a Honda man you'll know all about peak N hold injectors I'm sure.
Basically there are two families of peak and hold LPG injectors..
1. The rather simple solenoid type
2. The way more sophisticated and linear cylinder type, which are also a lot more expensive
You always need peak and hold injectors on a gaseous LPG car because they are the only type of injector that will flow enough volume, and LPG is a very voluminous fuel. But you do need different injector drivers for them to work which are typically hidden inside the separate LPG piggyback ECU used on most conversions.
It's well accepted in the LPG industry that the best, most reliable and fastest LPG injectors are from Keihin, interestingly the Japanese Keihin company are a wholly owned subsidiary of the Honda corporation which makes sense if you think about the huge knowledge Honda holds on peak and hold injectors.
You also may recall I fitted Keihins to 'Ol Gasbag' right at the beginning of the project, the intention was good but the whole thing fell down when I discovered Keihins run at 1.2Ohms instead of the LPG industry standard of 1.9Ohms.
With peak & hold injectors all the heat is at the injector drivers not the injector itself, this meant that running 1.2Ohm injectors through the Canems injector drivers (that we now know are designed for 1.9 Ohm injectors) caused them to critically overheat.
Not fun when you are 1000 miles from home in deepest France, but nothing that couldn't be overcome with the help of David Hampshire at Canems. TBH the problem was all mine, I just didn't understand the impact of running the super low impedance Keihins.
"You Live - You Learn", as they say
The solution in the short term was to fit a set of 1.9 Ohm Magic Jets that have been on the car and performing well ever since the early Keihin debacle.
But I have to say those Keihins were amazing while the ECU tolerated them, you could even start the car from completely stone cold on gas and drive away with no issues. So the idea was always to fit similar cylinder type injectors but we needed to find ones that run at 1.9 Ohms not 1.2.
Enter the latest Hana Golds, basically they are a well proven exact Keihin copy that run at 1.9 Ohms, I've know about these little wonders for a while now but we needed David Hampshire to destruction test his Canems dual fuel ECU with them on the bench before I committed my money.
The good news is there were no injector driver failures at all on the bench and David has given them the full thumbs up
, so as with all testing it's time to take it to the next level and see how they perform in the real world..The theory is these Hana Golds should prove way more controllable and linear than the simple Magic jets, just one advantage being it'll make mapping the car on gas a lot easier.
Typical benefits should be:
- Even better drivability
- Faster warm up phase (quicker switch overs from petrol to gas on warm up)
- Better fuel economy
- Faster response times and better throttle response
- Much more temperature stable (reduced cold start times and less heat soak issues)
- The ability to cope with higher line pressures (which gives other advantages I wont bore you with)
- The option to support anything from 350 - 400hp as a set of eight
To be fair to my simple & cheap as chips Magic Jets they have performed better than they have any right to, but lets see how we get on with these Hana Golds
After all, it's all part of the mater plan
Quinny said:
And in other news......my local LPG station has reduced his price by another 2ppl.......
Nice one Quinny But remember, the most important thing about the price trend of LPG is it's relationship to the price of petrol at the same station on the same day you're filling up.
I always say to myself this when I'm fueling the TVR with gas....
"If I was filling up with petrol instead of LPG right here right now (which being a dual fuel car is always an option), how much more would I be paying to cover the same distance?"
When doing this it's important to factor in the slightly poorer fuel consumption when you run on gas, the easiest way I've found to get a real world petrol cost equivalent MPG figure is to use the following equation.
Petrol price / LPG price X True LPG MPG = The petrol cost equivalent MPG
Here's two examples of how the cost differential can make a difference to the savings:
1. Petrol at £5.50 per gallon / LPG at £2.95 per gallon X Average LPG economy at 22 MPG = The petrol cost equivalent of 41 mpg
2. Petrol at £5.22 per gallon / LPG at £2.85 per gallon X Average LPG economy at 22 MPG = The petrol cost equivalent of 40.29 mpg
As you can see from the above two examples the price of LPG has become cheaper but the cost equivalent mpg has actually become worse. This seems counter intuitive at first but it's simply because the gap between the cost of petrol & LPG has narrowed.
The price of LPG has gone down, the LPG fuel economy of the car has remained exactly the same, but the car is now less economical than it was.
So you see it's less about the direct pump price and a whole lot more about the difference between the cost of the two fuels. And because this differential swings from day to day and from station to station the only time to reliably record your true petrol cost equivalent MPG is on the same day at at the same station that your filling up at.
The truth is the gap between petrol & LPG prices has been widening not narrowing lately, petrol is getting more expensive while LPG is either getting cheaper or at least staying static.
So my petrol cost equivalent MPG on gas is getting better and better by the day. The reality is over the last month or so I'm seeing figures more like this...
Petrol at £5.27 per gallon / LPG at £2.54 per gallon x 23.2mpg = a petrol cost equivalent of 48.13mpg
And I regularly see the magic 50mpg figure from my TVR if I buy my fuel at a certain station.
Not bad for a 140mph full fat V8 TVR using an engine Noah discarded when went with a more modern Mercury outboard
And the only sensible thing to do with all these savings is spend it all on a new fancy set of Hana Gold injectors
Dave's world of LPG is one messed up place folks
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