LPG Chimaera (Follow My Conversion)

[ChimpOnGas]

ClassiChimi said:

This must the figment of someone's emagination,,
It's all just words surely,,,,
Fantastic Dave, you must be so satisfied,,, mine does 27 mpg and I'm well happy with that,,
It's just increadable what your doing with your car,,,
You have blown the lid clean off this Lpg thing,,
Keep up the world class work.

Thanks Alun, I appreciate my project isn't everyone's cup of tea but it's pleasing when people understand what I'm trying to achieve here.

The truth is I'm still not quite hitting my own economy target I set when I embarked on this crazy journey. The measure of success for any LPG project is it's efficiency, and the one unavoidable fact about gaseous LPG systems is the engine will always consume more gas than petrol.

This is due to the lower calorific value of LPG by mass when it's in it's gaseous state, saying that if you keep it compressed at 50-60 psi right up to the injector it will remain in its liquid state. And what a lot of people don't know is that liquid LPG actually has a higher calorific value than petrol by mass so that means more power and more economy than petrol.

However if it remains in it's gaseous state the chemistry is unavoidable, these chemical rules dictate that even the perfect gaseous delivery system working under laboratory conditions would always deliver fuel economy no better than 18% behind what the same engine achieves on petrol.

I've proven my TVR will deliver a consistent 31mpg if driven in the same way as yesterday (70ish mph cruise), so my 24mpg on gas is actually a 22% loss of fuel economy and still a way off the magic 18% I'm trying so hard to achieve.

I believe the secret of turning my 22% into 18% lies in the ignition, we've already proved 110 Ron LPG will tolerate levels of advance that would be engine destroying on petrol. I'm already running right up to the maximum 49 degrees offered by the Canems system in the low load cruise sights and I'm convinced it'll take more without running into detonation.

Of course there comes a point where just adding more and more ignition advance will see cylinder pressures fall away but we haven't reached that point yet, and until David Hampshire at Canems increases the available advance we'll never really know where peak torque (and so maximum economy) exists.

The other idea to accompany the additional ignition advance experiment that may help the economy a fraction more is to go from batch fired injection to fully sequential, injecting the LPG at the back of the inlet valve just as it opens will certainly give a smoother idle and possibly even better refinement up to 2,000rpm. After 2,000 rpm I doubt it'll give much benefit, by that time everything is happening so fast you're more or less back to batch injection anyway.

But fully sequential injection remains an irresistible temptation all the same and if I'm having the ECU adapted for more advance I expect the draw of fully sequential injection will be too hard to resist, even if the likely benefits are small.

With both developments I think my 18% efficiency loss over petrol is a realistic target, and if I hit it 'Ol Gasbag' will be giving me 26mpg on gas which equates to the petrol cost equivalent of 60mpg!

After that only liquid injection will better it... Watch this space gas sniffers the next 'Gasbag' development ideas are already in the pipeline

[ChimpOnGas]

ClassiChimi said:

So will the said David Hampshire of Canams fame be able to give you that extra bit of advance to accommodate your experiments Dave?
Seems like a darn good idea to me,,

I expect so mate

He's already added gas pressure and gas temperature correction tables to the ECU and two additional inputs to accommodate the sensor signals.

The whole idea is we've been developing the system together as a three way team, David Hampshire on the engine management side, the Lloyd boys handling installation & mapping with me just coming up with a few daft ideas and the funding.

Actually everyone has their input so I'm far from being the only one with ideas, there's been a lot of those ideas by the way, they get thrashed out amongst the team with some making the real world but just as many never seeing the light of day after the discussions expose flaws in their theory.

Fundamentally if you boil it all down all we've actually done here is make a Range Rover engine run on LPG, and lets be frank... there's absolutely nothing new in that

TBH I feel we've nailed the project already, if I made no further changes the car would still be a massive success in my mind mostly because it drives nicer than I ever could have expected it too. Thats why I'm starting to look at other areas where I can enhance my driving pleasure such as a lighter clutch and deleting the TVR gear linkage to improve the shift.

With the car running so sweetly and economically I've started to notice those little niggles I've put up with in the past, and they suddenly become the primary areas of focus.

[ChimpOnGas]

ClassiChimi said:

,,,
As engineering exercise that even laymen like me can grasp, especially the way this thread has been conducted by its OP
Under sometimes heavy scrutinee is a testament to personal belief and sound engineering ideas,,,
To have got to the point of slickening up the gear change,,,
Dave cannot consider the cost when having to prove theory,,
I applaud the lLpg as a masterpiece,
ps Dave, can you consider the next leg too,,,
If the gearbox mods work, can your engineering team thrash out how to tighten up the drive train from gearbox and on to dif and drive wheels,,, mines had most things done and still it seems miss matched ? Sloppy,,,,
Just an idea sir,,,??

The drive train shouldn't be sloppy Alun, saying that I've added a set of SC-Power engine mounts to the latest works as my originals are really on their last legs.

The SC-Power engine mounts are costly so they better last, I'm lead to believe they're a little stiffer than the standard rubber compound, they'll certainly be a lot stiffer than my cracked and soft wit oil originals. So the hope is my new SC-Power engine mounts should at least tie the engine to the chassis a lot better than what I have now which in tun may help a little with the gear shift.

That's the only thing I can suggest to eliminate the slop you describe, assuming your prop UJs, CV joints and diff buses are in good shape I really can't thing of much else in the drive train to look at.

After my last round of tweaks I'll be taking a break from spending on the car.... apart from my annul dash to Le Mans I missed my normal TVR France touring trip this year due to the house renovations, so next year I'll be doing the grand tour again.

I know you'll understand the excitement and anticipation I'm feeling for my 2016 TVR euro tour more than most Alun because road trips are clearly close to your heart too, and I must admit I'm really looking forward to enjoying some 55mpg TVR continental touring in 2016.

Sometimes you reach such a sweet spot in a car's development it makes sense to slow down on all the fettling and just drive the begger

[ChimpOnGas]

spitfire4v8 said:

You probably don't need canems to do you something special for the extra ign advance.
Say your current least timing is a sensible 12-15deg around idle, you can move your crank reference trigger setting these (say) 12 degrees so your new idle timing number in the map is 0, but is actually 12deg static offset of advance. Then every other number in the ign map becomes offset by that 12 deg. hey presto your previous max of 49 deg is now 61.

Thanks, that makes sense

However I think I'd feel more comfortable seeing the true figures and having a wider table showing the full range of advance from true zero to a true sixty degrees. If I over type a cell with the figure 55, I want to know its 100% genuinely firing the spark at 55 degrees BTDC.

Interestingly it seems LPG needs lots more advance early on and in the low load cruise sites than on petrol, however as you get up towards the opposite corner of the table you may actually need less timing.

The good old bum dyno and the extensive experience of my mapping team has got us this far, but I'd like to see how close we've really got to the best maps? For that the car needs to go on the dyno so we can find where power rises then falls away again at each key load/RPM site, the truth is as it stands we have no conclusive proof where peak torque genuinely lives, only the dyno can tell us that for sure.

Perhaps the first step is to get it on the dyno before we ask David Hampshire for any more advance, if we see the torque is still rising in areas where we currently have 49 degrees then it could be worth while to approach Canems for more. On the other hand if we find peak torque actually lives at say 47 degrees, we'd know it would be pretty pointless to have a table that went any further than it does now (49 degrees).

What we've learned so far is being able to map LPG independently from the petrol is as big an advantage as we predicted it would be, this is especially true of the ignition side. Unsurprisingly given the completely different burn speed characteristics of LPG and it's huge ability to resist detonation you end up with a very different ignition curve/map.

The idea of fudging the timing up the scale is an option, but I think I'd be much happier seeing the true figures rather than needing to do the little sum in my head.

I'm sure David Hampshire will give me what I need, it may even be as simple as a software tweak he can email over?

But thanks for the idea anyway

[ChimpOnGas]

Ok gas sniffers, I've just realised I started "Project Gas Bag" exactly three years ago almost to the day, so I thought you'd like an update on the latest developments and the results arising from them.

Recently we've been testing my theory that there may be some more hidden LPG fuel economy beyond the 49 degrees of advance my Canems dual fuel system currently offers.

'Ol Gasbag' was bolted to Lloyd Specialist Developments hub dyno and the team tested my ignition timing theory on LPG at 50-60kPa load sites at 2000rpm, 2500rpm, 3000rpm and 4000rpm. They experimented with timing values between 40 and 49 degrees for each of these rpm sites.

During the session AFRs were also closely monitored to see how they were affected by changes in timing, and to ensure they remained inside ideal AFR tolerances for the 50-60kPa engine load window we were working in and looking to develop.

Here are the results:

• At 2000rpm torque was not improved beyond 45 degrees ignition timing

• At 2500rpm torque was not improved beyond 47 degrees ignition timing

• At 3000rpm torque was not improved beyond 44 degrees ignition timing

• At 4000rpm torque was not improved beyond 45 degrees ignition timing

Working on the basis that the least amount of ignition timing to produced peak torque at the given engine speed at 50-60kPa of engine load is preferable, a figure was settled on and the perfect light load map was developed.

The above figures clearly debunks my theory there could be benefit in extending the ignition table beyond 49 degrees of advance on light load cruise.

Am I disappointed?

Well no not at all, and here's why!

Firstly the dyno session allowed us to scientifically prove without any dispute where peak torque truly lives, this allowed the LSD team to effectively fine polish what was already an excellent set of maps (petrol & LPG). The team also discovered some more torque under full load at 4000-4500rpm on LPG by actually reducing the ignition timing slightly.

After the hub dyno runs 'Ol Gasbag's' power & torque graphs were compared against a very healthy but completely standard 4.0 litre petrol only Chimaera that had recently enjoyed a session on the same equipment. This back to back comparison using the same hub dynonometer proved conclusively that my Chimaera burning LPG is delivering 7% more power to the road than the fit standard petrol only Chimaera running Lucas 14CUX injection and distributor ignition.

I'm absolutely delighted with that, especially when many doubters tried to convince me I would be sacrificing a big chunk of performance and my TVR would be spoilt by converting it to consume LPG.

Now we've proved the car is actually more rather than less powerful on gas and that I haven't spoilt my TVR at all, we can start to look at how running a TVR Chimera on LPG genuinely improves fuel economy.....

Yesterday on the way back from Lloyds I filled up with LPG at the Murco fuel station Stonehenge. Their 95ron petrol was £1.00 per litre and their LPG was £0.45p a litre, that makes LPG just £2.04p per UK gallon!!!!

The last time petrol prices were £2.04p per gallon was 1983, I was 13 years old so was still 4 years off having a driving licence and many who read these pages were probably still in nappies

But what does all this really mean when compared with running my TVR on petrol which I freely admit has become quite cheap to buy of late?

Well if you take the £1.00 per litre for petrol and divide it by the £0.45p per litre I paid for LPG you get 2.222, now if you take my true LPG fuel economy and times it by 2.222 you get the petrol cost equivalent miles per gallon. IE the fuel economy any petrol car would need to deliver to match the pence per mile my LPG TVR is achieving.

Stay with me boys, here's the simple calculation...

My true LPG fuel consumption = 24mpg X 2.222 = 53.33mpg!!!

Yes that's right folks, while petrol is cheap these days... LPG is cheaper still, in fact if you purchase your LPG wisely its actually less than half the price of petrol.

In conclusion I've achieved a TVR that's both faster than when it was new, and one that now delivers the fuel economy equivalent of 53.33mpg!

All of this would be irrelevant if I'd lost drivability or refinement on gas, fortunately the truth is the Canems duel fuel system actually delivers big improvements in drivability over the standard car's old Lucas injection system & distributor ignition.

I'd say we've nailed it chaps

Now prepare yourselves for the next exciting development where we'll be taking 'Ol Gasbag' into a new stratosphere of 5.0 litre destroying performance while still retaining it's 50mpg plus fuel economy on cruise

Edited by ChimpOnGas on Sunday 28th February 11:17

[ChimpOnGas]

'Ol Gasbag' keeps delivering the goods and it's getting even cheaper to run

I've just worked out my latest cost equivalent economy from the last gas-up.

Last weekend the petrol at the Murco in Stonehenge was being sold at £1.13 a litre, but their LPG was just £0.46p.

So that's £1.13 / £0.46 = 2.456

Take my true LPG economy of 23mpg and times it by the 2.456 and I get a petrol cost equivalent figure of 56.5 mpg.

That is... I would need to be driving a petrol car that did 56.5 mpg to match me old gas powered 4.0 litre V8 engined TVR Chimaera.

Happy with that

[ChimpOnGas]

Four years on since I pulled the trigger on this alternative fuel madness I'm pleased to present Gas Sniffer update no 764.

'Ol Gasbag' continues to deliver the goods, and I'm happy to report the cost of the conversion has long since been covered by the considerable fuel savings I've enjoyed by running my Chimaera on LPG, I therefore declare the project a resounding success.

Admittedly I took a rather expensive approach to my conversion, but I make no excuses for this, I did so because I sought perfect reliability, drivability and best in class LPG economy. Some basic facts.... a full 14 gallon LPG fill costs £35 and easily takes me 290 miles, a full 12.3 gallon fill of petrol in a standard petrol only 4.0 litre Chimaera may take you the same distance if you're easy with the loud pedal, but will typically cost you a whopping £67.

So that's a clear £32 saved on every 290 mile fill and with the conversion cost all completely covered by past savings, that's £32 I'm enjoying spending on something more interesting than fuel. It's not quite half price TVR motoring but its as near as damn it, essentially the conversion has made the car as cheap and cost effective to use as my wife's little 75 horsepower 1.4 litre Nissan Micra yet it loses nothing in the way of performance or TVR magic.

I'll probably do about 6,000 miles in 'Ol Gasbag' this year, so that's more than 20 fill ups and a clear saving of £662, money I'll be spending on a nice return flight to Brazil

I'm still surprised more of you haven't converted to gas

[ChimpOnGas]

Hi Serban,

In the UK we have a saying.......

"There's more than one way to bake a cake"

You don't need to follow my Canems ECU, Hana Injectors & Prins vaporizer recipe... but I can confirm it works extremely well on my car.

I can't really comment on other recipes or the one you're proposing other than to say "untested is unproven", good luck with it though.

The one thing you'll immediately discover when you have the option of driving on either fuel.... is you'll never select petrol.

Dave

[ChimpOnGas]

Hi Serban,

The timing differences will be different for every engine, this is a forum specifically dedicated to the rather rare low production TVR Chimaera, do you own a TVR Chimaera?

If not your questions will be much better answered on a general LPG forum.

http://www.lpgforum.co.uk/

Just be aware the above forum is mostly full of LPG fitters looking for work.

Thanks for your interest in my car and LPG project, Dave.

[ChimpOnGas]

In theory development never ends and even something remarkable can always be improved upon, so the long and rewarding journey that is project 'Ol Gasbag' is set to continue with yet more innovation.

Things move on, so it's important to stay up to speed with the ever improving components available in the world of vapour injected LPG.

• Fluoropolymer coating
• Coil resistance: 1,9 Ω
• Opening time: < 2,0 ms
• Closing time: < 1,0 ms
• Max gas pressure: 4,5 bar
• Max gas flow: 115 l/min
• Temperature range: -40°C – +140°C

The traditionally impossible subzero cold starts on LPG may just have become a thing of the past

[ChimpOnGas]

Just the all-new TECH-YETI injector rail Alun, the latest thing in LPG injectors designed for use in extremely low temperatures.



They are faster than my current excellent Hana injectors offering even more accurate fuel dosing so should allow for an even smoother idle, even better drivability and enhanced fuel economy, also while my Hanas happily work down to 5 degrees these new injectors are designed to work in sub zero conditions which is a first in the world of LPG.

One of the reasons you traditionally cold start an LPG car on petrol is to allow engine coolant to warm the vaporisor, this is well understood but is actually only half the story, what is less well known is warming the injectors so they don't stick is as important... if not more important than warming the vaporiser. 'Ol Gasbag' actually already cold starts on LPG in the summer and autumn months, something long considered impossible by the LPG industry, these new injectors take things to a whole new level and should allow for deep winter cold starts on gas too.

The new LPG Tech Yeti injectors are internally finished with a fluoropolymer coating which not only helps them function in very low temperatures but also makes them extremely resistant to fuel contamination. LPG contains suspended oils that can collect inside and contaminate the delicate LPG injectors. These waxy heavy end deposits are the cause of many LPG issues so I use the latest filtration tech to eliminate it, but having injectors that are more tolerant to these contaminants in the first place just catches the issue at both ends to deliver unparalleled reliability.

Fluoropolymer coatings are blends of high performance resins and fluoropolymer lubricants, the coating is a superior dry film lubricant that produces a smooth, hard, slick internal finish that provides excellent corrosion and chemical resistance. Other benefits of fluoropolymer coatings include reduced friction, resistance to galling, non stick, non wetting, excellent electrical resistance and abrasion resistance too.

In theory these injectors should offer a longer service life, resist contamination better, offer an even better idle, better economy and work right down to the kind of sub zero temperatures that would have most LPG cars switching back to petrol. Better still the Yeti injectors will come with a revised ECU circuit design recently developed by the brilliant David Hampshire of Canems Engine Management Systems, this new strategy now shares the heat generated between the internal injector drivers and the injector itself which is of course super cooled by the LPG that flows through them. Taking a percentage of the heat away from the delicate injector drivers buried inside the Canems Dual Fuel ECU and sharing it with the injector enhances longevity and reliability, basically it will work like petrol where as petrol injectors are cooled by the fuel flowing through them, as we know heat is the biggest enemy of all electronics.

In theory these injectors are better, better, better in every way and offer a number of significant advantages, there's actually nothing wrong with my current excellent Hana injectors that are themselves a big step on from the slow type LPG injectors that were common just a few years ago, its just I can't help using the latest tech on 'Ol Gasbag' as I'm committed to a process of continual development to ensure this is the very best vapour injected LPG system in the world. LPG still carries the stigma of the bad old days where a car on gas typically exhibited poor economy, drivability and reliability issues, however what people need to accept is the reasons for this was all down to the crude systems and components used, during the last ten years especially LPG technology has followed the rapid developments in engine management technology so is a completely different animal these days.

With dirty diesels now exposed as being the polluting evil they've always been, low carbon super clean burning low emission LPG should really the government's solution to a filthy fuel they never should have promoted as the greener choice, diesel is the devils fuel while gas is for the angels

[ChimpOnGas]

Five years on and this project worked out better than I ever could have hoped

I'd also hazard a guess its the only TVR after market engine management conversion that's actually paid for itself.

Vastly improved drivability, no loss of performance, no loss of range, no real loss of luggage space, an engine that's smoother and runs cleaner, no way you'd ever know it's ruining on LPG.... oh and that 50mpg fuel economy too of course

Whats not to like?

[ChimpOnGas]

Tyre Tread said:

ChimpOnGas said:

Whats not to like?

The smug bd who keeps posting about it.

I guess being smug is my reward and response to all those people who said I shouldn't do it, what I'm really saying now is...

"I dont get why other's haven't done it"

Anyone who's ever been around Land Rover products will confirm its really not rocket science to run a Rover V8 on LPG, people have been successfully doing it for years. Ok so I did my best to make a better job of it, but the truth is thousands of 14CUX & distributor equipped Range Rovers and Discoveries have been successfully converted using simple and inexpensive components over the years, proving without any question it can be done on a budget with acceptable results.

We all like to believe our TVR Rover V8s are something special, but the truth is with the exception of the 5.0 litre what we actually all have is a Range Rover engine with some double valve springs and a slightly more progressive cam. The bottom line is if an old cheap Range Rover can be converted at 100,000 miles (and many are), and then go on to give another 100,000 miles service running on LPG (and many do), then the results really aren't going to be any different when you do the same to your RV8 TVR.

When people consider an aftermarket ECU swap for their Griff or Chimaera, as many frustrated with the 14CUX & distributor do, for just couple of hundred quid more than a petrol only Canems system they can have the dual fuel option. They can drive and enjoy the benefits on petrol first just as they would on an MBE or Emerald, but with the Canems Dual Fuel ECU when they're ready and funds permit they can follow my recipe and implement LPG element to give a no compromise 45-50mpg.

I'm not actually trying to be smug here, I'm just genuinely confused why other's haven't followed suit, I've done all the development work and will be more than happy to share what I've learned and the blueprint of my tank arrangement ect... which to be honest is all here for everyone to freely copy anyway. Maybe people are scared of LPG, maybe the stigma associated with the crude old mixer systems lives on? To people with these concerns I can reassure them things have massively moved on in the world of LPG and my system definitely works brilliantly, so well in fact it substantially better's the drivability of any standard petrol Chimaera I've ever witnessed.

The truth is gas isn't going away, and with ever stricter environmental rules appearing every year it may well prove to be the savior of the classic car world as its the only credible low emission strategy for older internal combustion engines vehicles on the road today. In ten years or less make no mistake we will all be driving electric cars, at which point an internal combustion engined car will seem like something from the stone age and driving one will come with a social stigma for sure like smoking cigarettes does today.

At this point I can see the government imposing usage rules on classic cars, perhaps a limit of 3,000 miles per year or less and trackers to monitor and police it, this will cover traveling to car shows and some light leisure use but that's it. However, if the classic is fitted with an engine management system to replace it's carbs and it's running cats & LPG you may well be given an exemption. Make no mistake an industry built around making classic cars greener is on its way, and LPG is just one way this will be achieved.

Of course you may argue this is all speculation, but the fact is some countries already have such rules in place on collector cars so its perfectly reasonable to assume these type of mileage restrictions on classics may be on the horizon for the UK too. And even if it never comes if you convert your Chimaera to LPG you'll instantly turn your 23mpg average TVR into one that averages 45-50mpg, which to me is a no-brainer.

All the environmental benefits aside, basically you swap £0.22p a mile in your TVR (at best) for a genuine £0.12p a mile, all you then need to do is divide the cost of the LPG conversion by the £0.10p per mile saved to show you how many miles you need to drive before you cover the cost. If the conversion cost you £2,500 that's 25k miles, if it cost £1,500 you'll break even at 15k miles.

While I appreciate 25,000 miles sounds like a lot, all I can say count up the miles you've done in the last few years and you may be surprised, this may also start you thinking about how LPG (in the long run) can make your TVR way cheaper to enjoy.... just saying

[ChimpOnGas]

motul1974 said:

Question: my future upgrades include the GEMS ecu I have waiting, how do you think this would manage running LPG?

The answer is it'll work brilliantly, just as it does on a GEMS Range Rover.

The first thing about the GEMS that makes it so much more convenient for an LPG conversion than the old 14CUX, is it has an OB2 connector, LPG ECU designers understandably make good use of this universal connector as it essentially carries all the data needed by the LPG ECU to do its job.

This makes the engine management side of an LPG conversion on a GEMS equipped car a simple plug in exercise, with a bit of additional LPG ECU calibration thrown in. No cutting and splicing wires, and because you've got distributorless ignition with piezo crystal knock sensors the GEMS ECU will keep challenging the point of detonation by continually advancing your timing, then backing it off a fraction for safety as it detects the early onset of det.

This means the GEMS ECU is effectively fuel/octane adaptive, and that's an important advantage with LPG because what a lot of people dont realise is LPG is 110Ron. The GEMS is also fully sequential which should deliver a small benefit over batch fired injection, all be it mostly at idle, finally the GEMS ECU is self learning so as long as you mostly drive on LPG it will find (to some extent) what it feels is your best fuel & ignition calibration.

Essentially the GEMS ECU will help you make a far better job of the LPG conversion than you could ever hope hope to achieve with the old 14CUX & distributor, all you need is a good 8 cylinder LPG ECU that's designed to plug into your GEMS OBD2 port. And the good news is they aren't expensive, for example LPG Tech offer a well regarded OBD2 compatible 8 cylinder LPG ECU for just £210.00.

http://www.lpgshop.co.uk/8cyl-ecu-lpgtech-tech-328...

I wish you all the best with your GEMS conversion, and once it's all working correctly I strongly encourage you to dual fuel the car too, the truth is once you get used to buying your fuel for £0.58p a litre I can guarantee you you'll never want to pay the £1.20p for petrol again.

Gas is good

[ChimpOnGas]

I get it's not for everyone, if your TVR is a low mileage weekend toy the ROI sums at least simply don't add up.

But I'm not that guy, I do use my Chimaera extensively simply because I love driving the car, as far as I'm concerned to leave it locked up in the garage is to complete miss the point of owning a TVR. While making the car more cost effective to fuel was the key driver behind converting my Chimaera duel fuel, ultimately there were a number of additional personal motivations behind the project.

It's important to remember this is a hobby for me too, so not everything I do with my TVR is done solely because I'm seeking cost savings, and I think that would be true for us all . Ignoring the significant price advantage for a minute, to me LPG is a very interesting low carbon high octane fuel and the only alternative fuel that's readily available across a huge number of UK forecourts, and of course it's even more popular on the European continent where I enjoy many rewarding touring adventures in my TVR.

The project was an opportunity for me to explore a better way of managing the fuel with the ECU designer, it's important to explain here that all other LPG conversions use a slave ECU piggybacked to the petrol ECU, what these slave ECUs are actually doing is looking at the petrol injector durations and trying to twist this data to make it appropriate for LPG, they also do nothing with ignition side which to my mind (and experience) misses the biggest potential advantage of running a 110Ron fuel.

The concept of the Canems Dual Fuel ECU different, its a singe box computer that completely does away with the need for the compromised slave ECU concept, this allows you to directly develop dedicated fuel and ignition calibrations for each fuel type. This means you're no longer trying to manipulate what is essentially the wrong (petrol) calibration to run LPG, with the Canems Dual Fuel ECU you are starting from scratch by building the right calibration for LPG in the first place.

For me the project has been a deep dive into engine management, ultimately it's given me the opportunity to prove LPG conversions can be approached in a different and I feel better way. Of course the system is rather 'niche market', most people converting to LPG are doing so on a budget and with so many different vehicles being converted the slave ECU idea becomes the most practical approach, even if in design terms it's a rather compromised Heath Robinson approach.

Make no mistake, if an OEM car maker was starting with a clean sheet of paper approach and designing a factory dual fuel vehicle from scratch, they would undoubtedly tap into their highly intelligent engine management team to eliminate the slave ECU idea completely to create something that follows the 'dedicated mapped by fuel' concept of the Canems Dual Fuel ECU.

This project has been extremely rewarding, not least because I was able to prove all the naysayers wrong and demonstrate you can convert a TVR to LPG without introducing any of the traditional compromises, it also gave me the opportunity to prove it can be done in a better way than taking the traditional slave ECU approach as used on all other LPG conversions.

Of course the 45-55pmg petrol equivalent fuel economy is rewarding too, but it was really the technical challenge that interested me, doing things differently is something I've always enjoyed, and as odd as it may sound to some I found this project significantly more stimulating and rewarding than simply shooting for a big horsepower number. I also strongly believe the Chimaera is the most underrated classic sports car option available anywhere, it's truly better in every dynamic way than an E-Type or Healey both of which I have extensive experience of, only the TVR's significant thirst holds it back from being the very most practical analogue classic sports car there is.

So I turned on that fuel consumption weakness and solved it, while at the same time making the car much much nicer to drive than any 14CUX and distributor equipped Chimaera could ever hope to be. The result quite simply being I use and enjoy my TVR more, which at the end of the day should be everyone's objective if like me you are truly passionate about these cars.

This was a super rewarding project that stimulated my mind, while there have been some challenges along the way solving them has actually been to most satisfying element. Ultimately the project turned our better than I could have ever hoped, so if anyone is interested in doing the same I would be very happy to share my detailed experiences and support them with dual fueling their Chimaera or Griff.

I also hope the above explains my multiple motivations behind dual fueling my TVR Chimaera?

Dave.

[ChimpOnGas]

ric355 said:

ChimpOnGas said:

Oh how clever you are (not), I absolutely feel others could benefit from this which is why I shared my project.

Your cynicism and negativity is only matched by the absence of your own interesting and innovative development projects.

If you don't get it that's fine, but investing energy in criticism seems painfully pointless to me as it really adds no value whatsoever.

Share your own innovations or move on.

Hold on I'm not trying to be unpleasant here. I think you've done a great job and I'm not knocking your project at all. You said you didn't understand why anyone else hadn't done it and I tried to give you an answer. Your subsequent post seemed to demonstrate that it was very much a personal challenge and I was just acknowledging that.

I have not at any point criticised what you have done, at least not intentionally.

Perhaps I misconstrue your comments, apologies.

Like I say its not for everyone, and I'm not trying to sell it to anyone, all I'm doing is presenting the project to stimulate thought and discussion around something a bit different to what you normally see on these pages.

To add balance there are some general elements of running gas that could be improved upon, and the big one for me is the forecourt LPG pump delivery nozzles we use here in the UK. These are heavy, clunky and poorly designed when compared with the super convenient light weight and easy to use systems found on the Continent.

Finding LPG stations isn't really an issue but prices vary wildly, the FillLPG app on my phone has proved invaluable in this respect as it gives live real time fuel prices and integrates with Google maps to take you right to the cheapest gas on route. Of course there's a little bit more planning involved than running on petrol, but the app solves this in seconds and I've never had to switch to petrol or deviate from my chosen route to find realistically priced LPG, the 300 mile range I designed into my conversion helps here too.

LPG also has a reputation for throwing up general running problems, stalling, misfires and drivability issues, but my experience has been to complete opposite. Perhaps it's the advantages of the Canems system I've already covered, but switching to gas for me has resulted not only in better drivability over the old 14CUX & distributor setup which you would expect, but the car also drives fractionally better on gas than it does on petrol since moving to the Canems system.

LPG in my case turned out to be a significant drivability improver, like I say it's been the complete reversal of what some experience when moving to gas, however I should probably point out many conversions are done on the cheap by people who claim to be experts but actually aren't , if you find a really good experienced LPG fitter any car can be made to run beautifully on gas.

There is a tiny loss of luggage space but it really is splitting hairs when you study it, I designed my conversion so I can still get the targa panel in the boot, and with that safely stored in the boot still be left with enough luggage space to take the luggage of two people touring Europe for two full weeks. The additional weight element ended well too, by stacking the two steel LPG tanks just behind the rear axle line where the standard petrol tank usually sits, it turns out handling was actually enhanced. These cars are very light at the back end in standard trim because all that sits behind the axle is a fiberglass shell that forms the boot, adding the extra weight has defitely delivered traction and handling advantages.

All this adds up to a situation that means I'd never go back to a petrol only TVR, obviously I do still have the option to burn petrol as the conversion is dual fuel, but I honestly can't remember the last time I used the car on the expensive stuff because quite simply the only difference is it costs me twice as much to go anywhere.

These are my truthful experiences, while there was an initial investment to convert the car in the first place that's long since paid for itself in fuel savings, essentially what I'm left with is a far nicer driving, cleaner burning, full fat V8 TVR that literally costs peanuts to fuel.

[ChimpOnGas]

stevesprint said:

One of my Griff friends followed the Chimp on Gas and was very surprised how quick it was.

I know its hard for people to accept, but LPG doesn't mean slow

Another LPG myth busted right there

[ChimpOnGas]

motul1974 said:

Well, I'm simply happy to know that there's another route to running my car in the future if the older petrol cars become an issue, so thanks for sharing your work. :-)

On the face of it the future of the internal combustion engine is bleak, the savior of classic cars will come in the form of a gas but it's not going to be LPG

There are currently two technologies fighting it out to replace the internal combustion engine:

1. Electric vehicles

2. Hydrogen fuel cell cars

In simple terms a hydrogen fuel cell uses hydrogen and a chemical reaction process to produce electricity, a hydrogen fuel cell is just an on board power generator for what is essentially an electric vehicle.

The interesting point is you dont necessarily need a hydrogen fuel cell to produce motive power from hydrogen, you can also burn it in an internal combustion engine. Whats even more interesting is the growth in hydrogen fuel cell cars on our roads is dicatating the number of fuel stations offering hydrogen must grow in response, so the availability of hydrogen is only going to improve.

Indeed two years ago the only hydrogen close to me was in Ealing, I can now buy hydrogen in many locations in and around London and across the south of England. The rise in hydrogen fuel cell cars will create a network of hydrogen stations that will rival anything we currently have for LPG, and those stations won't care if you are buying hydrogen to make electricity in your hydrogen fuel cell car... or burning it in your internal combustion engine .

The fossil fuels we currently burn in our internal combustion engines are all hydrocarbons and that includes LPG, they are all a mix of hydrogen atoms and carbon atoms which is why we refer to them as hydrocarbons. LPG is cleaner because it typically only contains three carbon atoms whereas petrol contains 4-12 carbon atoms (typically 7), diesel is even worse as it contains 12–20 carbon atoms (typically 15). This is why diesels dirty their oil almost instantly after an oil change, it's also why the oil on my LPG Chimaera stays as clean as new for 10,000 miles or more, and my combustion chambers remain spotless compared with a Chimaera burning petrol .

Pure hydrogen as the name suggests contains zero carbon atoms, it is therefor not a hydrocarbon like the fossil fuels we currently burn, when you burn pure hydrogen in an internal combustion engine the only byproduct is pure H2O (water), effectively any internal combustion engine burning pure hydrogen instantly becomes a zero emissions vehicle. As the network of hydrogen fuel stations grow to support hydrogen fuel cell cars I expect a similar decline in LPG stations, my response will be to convert my Chimaera to burn hydrogen instead of LPG.

Essentially by a lucky twist of fate the increasing availability of hydrogen because of the rise in hydrogen fuel cell cars becomes the savior of all internal combustion engined vehicles, this will be particularly relevant to the only internal combustion engined vehicles that will remain... IE classic cars . In ten years time nobody other than classic car owners will have an internal combustion engined car, and there will be intense pressure on these classic car enthusiasts to do something about how dirty they are.

Converting an internal combustion engine to burn hydrogen is much the same as converting it to run on LPG or compressed natural gas (CNG). Basically like LPG & CNG you can convert any internal combustion engine to run on hydrogen, the key difference between LPG and Hydrogen is the pressure the hydrogen pump delivers the fuel at and therefor the pressure you need to store in at in the car.

All these gaseous fuels (LPG, CNG, Hydrogen) need to be compressed to turn them into their liquid state or you'd need a huge balloon on top of the car just to travel 50 miles, LPG becomes a liquid when you compress the gas between 32 - 50psi so it's typically delivered at the pump and stored in the tanks at 60psi.

That's a very low pressure when you compare it with CNG, but get ready folks, hydrogen needs to be stored in your car at an insane 5,000psi to ensure it remains a liquid. This means you need special composite tanks, my steel LPG tanks just wouldn't cut it,you also need a vaporiser that's capable of bring the pressure down from 5,000psi to 125psi before it's delivered to the injectors. To put the vaporiser element into perspective my LPG vaporiser only needs to drop the pressure from 60psi to 28psi.

Another difference is LPG in it's gaseous state caries 18% less calorific value than petrol which is why I designed my conversion to carry 18% more of the stuff so I can still achieve the standard petrol Chimaera's range of 300 miles. However, hydrogen in it's gaseous state caries 30% less calorific value than petrol so not only would you need special composite tanks that cans sustain a whopping 5,000psi they need to be big too to achieve your range, for the 300 mile you'd need to carry 17 gallons of the stuff which is going to take up a lot of boot space.

The answer to the calorific value issue is to inject the gas as a liquid not a gas, both LPG and hydrogen in their liquid state have a greater calorific value than petrol so you'd actually need to carry less of the stuff, 11 gallons of hydrogen injected as a liquid would easily give you your 300 miles and because your keeping it as a liquid right up to the injector you clearly dont need a vaporiser which obviously eliminates the pressure drop requirement in a stroke.

So you see, LPG is just a stop gap, the future for the internal combustion engine (and that really just means classic cars) is super high pressure liquid hydrogen injection, and thanks to the rise hydrogen fuel cell cars we will be able to buy our hydrogen everywhere. Our cars will immediately become zero emission vehicles, restriction on their use will be lifted, and the glorious sound of the mighty V8 will remain with us forever .

LPG is a great stop gap, but the truth is hydrogen is what we'll all be burning in our classics in 10-20 years time

More about burning pure hydrogen in an internal combustion engine here....

https://www1.eere.energy.gov/hydrogenandfuelcells/...

[ChimpOnGas]

What people dont realise is innovators like Rouch have been running internal combustion engines on pure hydrogen for years.

https://www.youtube.com/watch?v=80xP7XSDDgs

https://newatlas.com/hydrogen-conversion-for-petro...

And while they are focusing on local delivery vans, they also have a Ford GT40 running on pure hydrogen. The technology to run an internal combustion engine is well understood and has been around for years, most importantly the infrastructure to make the fuel a practical proposition is already here too.

Only a few weeks ago I pulled into the motorway services on the M40 at Beaconsfield to buy some LPG only to find it wasn't available as there was some tank installation work going on, I asked the attendant if they were updating their LPG tanks and he said no "we are installing a hydrogen pump".

Of course this hydrogen infrastructure is not being created for internal combustion engined cars that burn hydrogen, it's there for hydrogen fuel cell cars, currently in the UK you can buy two different hydrogen fuel cell cars:

• Hyundai's ix35

• Toyota Mirai

It's really just a lucky twist of fate you can also burn hydrogen in an internal combustion engine, so we should all be getting behind hydrogen fuel cell cars as they will save our classic fuel burners.

The challenge for hydrogen fuel cell cars is the extremely rapid advances in battery technology, currently hydrogen fuel cell cars have their place because it's relatively straightforward to carry sufficient hydrogen in a car to allow it travel 300 miles or more, you can also completely fill a hydrogen fuel cell car with 300 miles of fuel in 3 just minutes. Currently the best electric cars take 30 minutes to speed charge to 80% which at best means only 180 miles, but in just five years time because charging and battery technology is progressing so quickly you'll be able to add a 300 mile charge of electricity in just 5 minutes.

At which point the current fill speed and range advantages of the hydrogen will be completely lost, hydrogen fuel cell cars will become the Betamax of the alternative fuel world and everyone will adopt an electric car instead, the hydrogen stations will disappear and us internal combustion lovers and classic car owners will be back to square one. This is a real shame but I could easily be wrong with my pessimistic prediction for hydrogen as I dont posses a crystal ball, I genuinely hope hydrogen fuel cell cars catch on as I will definitively convert my LPG TVR to run on hydrogen if the infrastructure remains.

Actually if you look at the UK hydrogen infrastructure map today, it's already a surprisingly comprehensive picture, and the roll out plans to improve it are very aggressive and well published. In March 2017 the government created a £23 million fund to accelerate the take up of hydrogen vehicles and roll out more cutting-edge infrastructure.

Here's how the hydrogen infrastructure looked just 2/3 years ago...



And here's what it looks like now in the first quarter of 2018...



So maybe hydrogen is here to stay after all?

[ChimpOnGas]

For anyone still wondering why I continue to persevere with LPG after more than five years since I started all this , the following simple calculations should help.

Here's yesterday's example using my local Sainsburys forecourt prices:

Petrol = £5.72 per imperial gallon (cheapest petrol in my area)

LPG = £2.45 per imperial gallon (at the same station)

£5.72 / £2.45 = 2.334 (the multiplier)

So to find out the petrol consumption I'd need to achieve in my TVR to match what I achieve when running the car on LPG I simply take my true LPG consumption of 21mpg and times it by the above multiplier.....

21mpg X 2.334 = 49.01mpg..... 'Petrol Cost Equivalent'

Not bad for a 150mph 4.0 litre V8 TVR Chimaera that gets from rest to 60mph in five seconds



The above is the fairest way to demonstrate my petrol cost equivalent MPG figure as it compares the price of the two different fuels on the same day at the same station.

However, if I run the same calculation using the average petrol price local to me which is a painful £6.00 a gallon, the results are even better.

Petrol = £6.00 per imperial gallon (average in my area)

LPG = £2.45 per imperial gallon

£6.00 / £2.45 = 2.448 (multiplier)

21mpg X 2.448 = 51.41mpg..... 'Petrol Cost Equivalent'

The above demonstrates what actually really matters is the percentage cost difference between the two fuels, this is because on any given day if I wasn't running on LPG I'd be forced to run my TVR on petrol like everyone else does. So it's not actually the displayed forecourt price of the fuels that counts, the important element is actually the price gap between the two fuels at the same station on the same day.

Quite simply if I wasn't buying their LPG I'd be forced to buy their 95Ron petrol instead.... or I'd be going nowhere fast!.

Transforming a thirsty 4.0 litre TVR Chimaera that averaged 23mpg on petrol and turning to a 50mpg vehicle is quite literally game changing, and as petrol prices continue to climb LPG becomes an even more appealing option

I could never go back to petrol, the thought of paying to fuel a petrol only Chimaera actually scares the life out of me, this why I continue with the Canems Duel Fuel engine management system.