Howdy all,
Myself and a mate (who is far more technically minded than myself) are looking at a DIY lpg install on my 1998 XJR and we're looking for some advice on the BiGas kit or on similar installations as we're well aware it's a big job particularly for a first install!
We've decided on a BiGas LPG kit over a Vogas/Romano for a number of reasons. The first reason is that I've heard good things about Tinley Tech's service and the price is certainly fair given the customer service that many people have encountered.
We've also decided that it's best to use a kit that is capable of switching back to petrol easily under higher engine loads as we're not really wanting to push a kit or the engine to the full 370bhp on gas. We've decided it's unnecessary risking lean running, temperature increases and pushing injectors to the limit when I'm quite happy to pay for petrol if I'm heavy footed.
For that reason we've been informed the Bigas kit not only allows the "split-fuelling" we desire but is more suited to a DIY install as it features an auto-calibrate feature which can then be adjusted for the higher loads. We've also been informed that the Vogas kit also has this feature but is much more difficult to set up so I've decided against it for that reason.
We are however still "umming" and "arring" over the install and we're desperate to get our hands on an installation diagram. Can anyone help us out? I'm tempted to call Tinley Tech but I'd rather try here first.
If anyone can provide advice on either the Bigas kit/a better kit to use/experience of XJR installs (or any other advice based on the above!) it would really be a big help guys thanks!
(Oh and we're well aware of the Nikasil issues! My car's compression is fine!)
Any help appreciated guys thanks!
Gareth
BiGas kit on 1998 XJR 4.0 Super V8
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Pretty much all the LPGers on here use the old crude system which is effectively just a carburettor for propane, and a petrol cutoff of some short.
What you are talking about is a league away (in terms of complexity and expense!!)
I think in this instance I would have a real good chat with a couple of LPG vendors, but pay particular attention to how their system interacts with the existing engine management system (and doesn't cause faults etc!)
Chris.
What you are talking about is a league away (in terms of complexity and expense!!)
I think in this instance I would have a real good chat with a couple of LPG vendors, but pay particular attention to how their system interacts with the existing engine management system (and doesn't cause faults etc!)
Chris.
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Series IIA 4.6 V8
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Series IIA 4.6 V8
R/R P38 4.6 V8
R/R L405 4.4 SDV8
Aye it's going to be a tricky job. We've not even begun to start tackling the ECU issues. The Bigas system we're looking at allows an autocalibrate and fine tuning option (and is the most commonly used system apparently with many vendors that can help us out if we need an experienced touch!). So we should get there!
Just for your interest; contrary to what a lot of people say about Nikasil liners, assuming they have not already worn, they actually should out last their steel equivalents. They also should not wear further due to tighter regulations on the sulphur content of fuel (Also LPG has none) and the initial failures were due to this. In short, if it hasn't failed and compression is good. There is no reason not to trust one.
In terms of "I wouldn't fit it to my Jag", which I hear more than I'd like; My mint low mileage XJR set me back £4500 and the only thing that doesn't make the car perfect is the fact it does 13mpg. At 22 years old I was fortunate enough to be able to get insured cheaply and buy it cheaply I see no reason to continue the trend when it comes to running costs. Especially as a well fitted LPG system won't lose performance and will only set me back around £1200. This will be recouped in fuel costs at around 14,000 miles (just under a years driving for me).
So if the only problem with your daily drive is the fuel it uses, and you have the expertise at hand to solve the problem, then why not sort it? It means I can drive my 370bhp luxury car everyday, everywhere and on a modest income. I fail to see why anyone wouldn't.
Just for your interest; contrary to what a lot of people say about Nikasil liners, assuming they have not already worn, they actually should out last their steel equivalents. They also should not wear further due to tighter regulations on the sulphur content of fuel (Also LPG has none) and the initial failures were due to this. In short, if it hasn't failed and compression is good. There is no reason not to trust one.
In terms of "I wouldn't fit it to my Jag", which I hear more than I'd like; My mint low mileage XJR set me back £4500 and the only thing that doesn't make the car perfect is the fact it does 13mpg. At 22 years old I was fortunate enough to be able to get insured cheaply and buy it cheaply I see no reason to continue the trend when it comes to running costs. Especially as a well fitted LPG system won't lose performance and will only set me back around £1200. This will be recouped in fuel costs at around 14,000 miles (just under a years driving for me).
So if the only problem with your daily drive is the fuel it uses, and you have the expertise at hand to solve the problem, then why not sort it? It means I can drive my 370bhp luxury car everyday, everywhere and on a modest income. I fail to see why anyone wouldn't.
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Rossco
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Go for it.
Everyone told me that I couldn't run an LPG vaporizer system on a 3.8ltr at 7psi ......so I did and it worked fine.
Ok it takes some doing to set it up but if you make sure you have a wideband O2 meter fitted even if it's not controlling anything and just telling you whats happening you'll soon get it tuned.
I'm about to start on the LPG setup for my new 8 litre 500bhp setup.....
Everyone told me that I couldn't run an LPG vaporizer system on a 3.8ltr at 7psi ......so I did and it worked fine.
Ok it takes some doing to set it up but if you make sure you have a wideband O2 meter fitted even if it's not controlling anything and just telling you whats happening you'll soon get it tuned.
I'm about to start on the LPG setup for my new 8 litre 500bhp setup.....
G
putting 8 litres in a rangerover is only done by those that avoid growing up, damn good thing too
By the way If you do go LPG (and I would still advise not) I would very seriously consider only running LPG, don't dual fuel it (it will also mean you can compensate for the weight of the gas tank). Also raise the boost from the supercharger as far as you can. LPG has an equivalant octane rating of between 110 and 115, for it not to burn out your exhaust valves you need to get the stuff to burn before they open, to do this you need to get the chamber pressure up (not just advance the ignition) If you can I would also retard the exhaust cam aswell so they open later.
Mike
putting 8 litres in a rangerover is only done by those that avoid growing up, damn good thing too
By the way If you do go LPG (and I would still advise not) I would very seriously consider only running LPG, don't dual fuel it (it will also mean you can compensate for the weight of the gas tank). Also raise the boost from the supercharger as far as you can. LPG has an equivalant octane rating of between 110 and 115, for it not to burn out your exhaust valves you need to get the stuff to burn before they open, to do this you need to get the chamber pressure up (not just advance the ignition) If you can I would also retard the exhaust cam aswell so they open later.
Mike
poppet valves rule!
Hmm... I'll put to the engineer! Watch this space!kiwicar wrote:G
putting 8 litres in a rangerover is only done by those that avoid growing up, damn good thing too
By the way If you do go LPG (and I would still advise not) I would very seriously consider only running LPG, don't dual fuel it (it will also mean you can compensate for the weight of the gas tank). Also raise the boost from the supercharger as far as you can. LPG has an equivalant octane rating of between 110 and 115, for it not to burn out your exhaust valves you need to get the stuff to burn before they open, to do this you need to get the chamber pressure up (not just advance the ignition) If you can I would also retard the exhaust cam aswell so they open later.
Mike
Hi Just re reading your posts, I think your MPG figures are very low for that car... My Wife has an XK8, and we get in the 18 to 22 in town (MK) and around 28 on a run overall averages in the region of 24, 25 ish. When the local jag dealer lends us a car it's an Xj8 and gives with in 2 MPG of this. Even allowing 10% for the blower 13mpg is very low for that engine, the old 4.2 XJ 6 used to give averages in the low 20's and near 30 on a run and that engine originated from a 1936 design. Before you spend money on LPG kits I would get the fuel economy where it should be in the 20s .
Mike
Mike
poppet valves rule!
It's averaging about 14mpg around town but that's stop start traffic. Average speed in the car at about 12mph.On the motorway 28/29mpg which is the published manufacturing figures. Combined MPG is cited by EVO magazine as 24. So.... 24*2=48 - 29 = 19mpg in town (Obv this estimate is assuming it has linear fuel consumption which is isn't)
I'm getting 5mpg less than "urban" driving figure but it's solid stop start traffic living in a hilly city. My average speed was 12mph.
Sounds alright to me? I would think 10% for the superchager is a little optimistic to be honest... It's big 'un.
Also hooning around the country lanes didn't really yield poor consumption either. Quite the contrary actually. Much better than expected.
The car's just been serviced and the compression seems fine so I'm not entirely sure what I can else I can unless you've any ideas?
I'll check the air filter and plugs and do another compression test end of this/next week.
I'm getting 5mpg less than "urban" driving figure but it's solid stop start traffic living in a hilly city. My average speed was 12mph.
Sounds alright to me? I would think 10% for the superchager is a little optimistic to be honest... It's big 'un.
Also hooning around the country lanes didn't really yield poor consumption either. Quite the contrary actually. Much better than expected.
The car's just been serviced and the compression seems fine so I'm not entirely sure what I can else I can unless you've any ideas?
I'll check the air filter and plugs and do another compression test end of this/next week.
Hi G
is the XJ an electronic throttle like the XK? just thinking about it further I think you are going to have an issue with the combined engine/gearbox managment if it is...
The fueling and throttle position on the XK (on petrol) is linked into the gearbox managment, if you go over to fueling via what ammounts to a big fixed venturi carb I think you will have an interesting time getting it to pull away as the fueling will then be indipendent of the throttle position and gearbox. You will have to spend some considerable time setting these up to match what the throttle pedle now does and the fuel curve against throttle plate against gearbox setting. I believe this is a big hassel for those who convert the XK to a T56 box to go manual, they have to fit an auto box emulator and reprogramme the ECU to make the throttle plate "follow" the peddle.
To get this to work I think your budget is going to have to be big... I would think you would need an LPG injection system (not big carb and vaporiser) (say £2 to £2.5 k) an exhaust cam reset (£200) new pullys for the supercharger £600+ (I have seen £1200 quoted) someone to rework the ECU to sort out the throttle, say 2 days on a roling road and a jaguar ecu specialist £1500 min, gearbox specialist to do same on the gearbox ECU £750, two days on a Rolling road to sort out the fuel map £700. You could buy an aufull lot of petrol for the £6000 plus you are in for.
Alternativly you can buy an old saxo/vectra deisel and insure it as a second car for £1200, use that around town and enjoy the XJ the way it was meant to be.
Mike
is the XJ an electronic throttle like the XK? just thinking about it further I think you are going to have an issue with the combined engine/gearbox managment if it is...
The fueling and throttle position on the XK (on petrol) is linked into the gearbox managment, if you go over to fueling via what ammounts to a big fixed venturi carb I think you will have an interesting time getting it to pull away as the fueling will then be indipendent of the throttle position and gearbox. You will have to spend some considerable time setting these up to match what the throttle pedle now does and the fuel curve against throttle plate against gearbox setting. I believe this is a big hassel for those who convert the XK to a T56 box to go manual, they have to fit an auto box emulator and reprogramme the ECU to make the throttle plate "follow" the peddle.
To get this to work I think your budget is going to have to be big... I would think you would need an LPG injection system (not big carb and vaporiser) (say £2 to £2.5 k) an exhaust cam reset (£200) new pullys for the supercharger £600+ (I have seen £1200 quoted) someone to rework the ECU to sort out the throttle, say 2 days on a roling road and a jaguar ecu specialist £1500 min, gearbox specialist to do same on the gearbox ECU £750, two days on a Rolling road to sort out the fuel map £700. You could buy an aufull lot of petrol for the £6000 plus you are in for.
Alternativly you can buy an old saxo/vectra deisel and insure it as a second car for £1200, use that around town and enjoy the XJ the way it was meant to be.
Mike
poppet valves rule!
Alright mate,
A lot of that was over my head I'm afraid.
I'm pretty sure the x308 XJR is fly-by-wire. However, in terms of fuelling, the system we've got in mind piggy-backs the ECU. Effectively we're just altering what the injectors we're using (gas/petrol). So the autobox shouldn't need playing with. In terms of the fuelling the piggy back system comes with an auto-calibrate function with the RPM curve and fueling sorted.
We can also map the ECU ourselves with the software provided in the kit (we have some limited experience of this). It will be very much trial and error but hopefully the auto-calibrate function will take the edge off.
When the gas is on the new map will be used. When it's on petrol (heavy load/warming up vaporiser) the standard map will be running so there should be no need for a remap of the standard Jaguar ECU.
The system we've also sourced, as you correctly pointed out, is a multipoint injection system with an ENOURMOUS vaporiser and injectors (fit for purpose). Incidently it only costs £1200 delivered with VAT and all ancilliaries. It could in theory run the car with only GAS only even at higher loads but we're not wanting to sacrifice any of the XJRs power as we feel this would be detrimental to the cars appeal (or push components too hard).
In terms of previous conversions they've all be done without supercharger pulleys/rolling roads/cams. So I see no reason why ours would be any different with the same equipment.
So it really won't cost that much at all that's why I'm doing it. It can be fitted by a local company for £2000 so if it looks like DIY costs will escalate I'll just give it to them. The conversion has been done dozens of times with good results. There is even a company I know of that specialises in converting this car. I've done a fair bit of research.
Buying another car; I have the GFs 993cc Micra. But when, as I've explained, this LPG installation can be done for ~£1500 (max, including all additional tools) and then the XJR will offer better equivalent mpg with no power compromise I think the question becomes "How can I afford not to do this?".
It would also be a cold (and expensive!) day in hell before I paid Jaguar to do a rolling road remap. If I could afford to pay that I could afford to pay the petrol! If I needed it remapped I would probably go to paramount performance (Renowned Jag specialists only circa £600).
Incidently I got 20mpg on the way home yesterday! Woohoo.
A lot of that was over my head I'm afraid.
I'm pretty sure the x308 XJR is fly-by-wire. However, in terms of fuelling, the system we've got in mind piggy-backs the ECU. Effectively we're just altering what the injectors we're using (gas/petrol). So the autobox shouldn't need playing with. In terms of the fuelling the piggy back system comes with an auto-calibrate function with the RPM curve and fueling sorted.
We can also map the ECU ourselves with the software provided in the kit (we have some limited experience of this). It will be very much trial and error but hopefully the auto-calibrate function will take the edge off.
When the gas is on the new map will be used. When it's on petrol (heavy load/warming up vaporiser) the standard map will be running so there should be no need for a remap of the standard Jaguar ECU.
The system we've also sourced, as you correctly pointed out, is a multipoint injection system with an ENOURMOUS vaporiser and injectors (fit for purpose). Incidently it only costs £1200 delivered with VAT and all ancilliaries. It could in theory run the car with only GAS only even at higher loads but we're not wanting to sacrifice any of the XJRs power as we feel this would be detrimental to the cars appeal (or push components too hard).
In terms of previous conversions they've all be done without supercharger pulleys/rolling roads/cams. So I see no reason why ours would be any different with the same equipment.
So it really won't cost that much at all that's why I'm doing it. It can be fitted by a local company for £2000 so if it looks like DIY costs will escalate I'll just give it to them. The conversion has been done dozens of times with good results. There is even a company I know of that specialises in converting this car. I've done a fair bit of research.
Buying another car; I have the GFs 993cc Micra. But when, as I've explained, this LPG installation can be done for ~£1500 (max, including all additional tools) and then the XJR will offer better equivalent mpg with no power compromise I think the question becomes "How can I afford not to do this?".
It would also be a cold (and expensive!) day in hell before I paid Jaguar to do a rolling road remap. If I could afford to pay that I could afford to pay the petrol! If I needed it remapped I would probably go to paramount performance (Renowned Jag specialists only circa £600).
Incidently I got 20mpg on the way home yesterday! Woohoo.
