Thread: D-gas versus Dieselgas

I've got a 300Tdi -

TheD-Gas system is a much simpler system than the ECU controlled one. Just injects the gas according to boost pressure, so you have to choose a rev range you normal run at and tune if to that - for me that 2000-2400rpm. If you want more power, go with a bigger jet, if you want better economy, use a smaller jet. From what I've read, it may take one or two jet changes to get it right for what I want.

On a simple mechanical tdi motor, it's all I think you need, if I had a chipped Td5 and looking for max power, I might have gone with the other ECU systems, but they are more than $1700 more - the fuel savings will take much long to pay for the unit to pay for itself.

HI ALL,
HAD A SEQUENT 2 SYSTEM FITTED TO MY 02 DISCO TD5 AUTO A MONTH AGO AT ALL 4X4 NEWCASTLE,WHAT A GREAT INSTALLATION ,VERY NEAT AND YOU CAN SEE WHERE YOUR AND THE GOVT. MONEY WENT,THERE IS A LOT OF GEAR IN THIS SYSTEM .
DUE TO GO IN FOR THE FINAL TUNE UP OF THE LPG RATIO AS AT THE MOMENT USING A BIT MORE GAS THAN IT SHOULD,
REHASHED THE EGR VALVE SETUP REMOVED ALL THE INTERNALS AND EXTERNAL BITS FROM THE HOUSING THEN MACHINED A STEEL PIPE TO FIT INSIDE THE HOUSING,PRESSED IT IN WITH SEALANT APPLIED,THIS CLOSES ALL THE HOLES THEN FITTED A 3mm BLANK PLATE TO THE INLET OF THE HEAT EXCHANGER ,ALL'S WELL,COST ZERO $
CHEERS
SPITTY

HI,

It should have beena couple of months now since your install.

I purchased a TD5 recently with the same itention for a conversion.

Can you share with us which one you chose and how it is doing?
Are you happy with the conversion?
Where is the LPG tank in a Disco, and how often do you fill it up?

Do you get improved fuel efficiency as well?

Thanks !

Dazzler

Originally Posted by Dazzler001

HI,

It should have beena couple of months now since your install.

I purchased a TD5 recently with the same itention for a conversion.

Can you share with us which one you chose and how it is doing?
Are you happy with the conversion?

Do you get improved fuel efficiency as well?

Thanks !

Dazzler

Hi,

Mine is a 300tdi and I went for the D-gas system. Put quite simply, it doesn't work, and I expect to go to court to get a refund. D-gas on their website say they offer a money back guarantee but when put to the test they refuse.

I have been farting around for five months now. My trouble is that I have an engineering background so I don't rely on subjective results - I measure things. There is no measurable improvement in performance on the road. At partial throttle it DOES help to turn on the gas. At full throttle, there is no measurable benefit.

I am now on the third control box. The first one didn't work at all, the second one worked for a day. This one works in that it does inject gas, but the percentage gas usage is all over the place. I have just returned from a months holiday and tested the system over lots of kilometres. The gas used varied from 8.5% to around 25%. I am quite sure it sometimes peaked a lot higher because occasionally I thought the engine knock increased substantially.

Half way through the trip I let the gas run out, and it felt a much happier engine for the rest of the trip. That is subjective of course.

Don't be fooled by the fact that the gas does help at partial throttle opening. It certainly makes the car feel a little more lively because you don't press the throttle down so far. What really counts is what it does at full throttle. On mine it does nothing.

Useage of diesel fuel was marginally improved, though that could be due to changing winds and driving conditions. However, the total COST was higher during the 3,000 k's with gas than the remaining 5,000 k's without.

All in all, I feel very ripped off. I have spent 42 hours of my own time trying to get this sytem working, following instructions form both D-gas and the installer. On my vehicle, it is a complete dud.

I look forward to hearing other results - preferably non-subjective ones. Have any of you done any real-world full throttle perfomance testing?

Cheers all,

Paul

I don't have anything subjective, but the on mine, I used about the same amount of total fuel (diesel + gas) as before, except the gas was cheaper, and I do notice and make use of the extra power. There is a steep hill on the freeway I drive up every night - without gas - I can just hold 100kph foot flat to the floor, with the gas, I have to back off a bit or I accelerate on the hill. I can't say I have tested it on a long run, but I was not as impressed by the fuel consumption as what had hoped, but there was definitely more power according to my "seat of the pants" dyno.

That was about 2 months ago - the clutch broke on my car and i decided to fit and automatic transmission - it has been quite a mission as I did not have all the parts, at first, and I've kind of lost interest for now. Probably because I bought an Audi B5 S4 - 2.7lt twin turbo and I must admit is is much more fun to drive than a diesel discover. Cheaper to run - cost $60 per week to run vs the $70 on the diesel+gas and 0-100 in 5 seconds vs 15 minutes

Originally Posted by Iain_B

I don't have anything subjective, but the on mine, I used about the same amount of total fuel (diesel + gas) as before, except the gas was cheaper, and I do notice and make use of the extra power. There is a steep hill on the freeway I drive up every night - without gas - I can just hold 100kph foot flat to the floor, with the gas, I have to back off a bit or I accelerate on the hill. I can't say I have tested it on a long run, but I was not as impressed by the fuel consumption as what had hoped, but there was definitely more power according to my "seat of the pants" dyno.

Interesting Iain, thanks for the reply. The seat-of-the-pants dyno is fine - but did you feel it while on full throttle? There are many reasons why a particular hill might stop you at 100KPH one day and 120KPH the next day.

I felt the seat-of-pants benefit on mine too when accelerating on 3/4 throttle. Flicking it on and off while on full throttle I could feel nothing - that is why I did lots of road testing with GPS speedo and stop watch.

What system did you have installed? Is your Disco a 300tdi? If there is a system that really works (on a 300tdi) I will try again. Meanwhile, I have since spoken to two other chaps with the same system I fitted - they report exactly the same lack of real benefit. We might be getting a bit of a class action going. We all just want our money back, like they promise on their website. Then maybe we can afford a working system.

Cheers,

Paul

I just had D/gas fitted but it is to early to say anything as I've only used one tank but I have noticed my engine picks up when the gas is supplied and it rev's harder through the gears.The bloke that fitted it has three different sized jets to try .030-.040-.050thou but the .040 seems good as fitted.I have found my diesel usaged hasn't gone down but the top speed has gone up,an indicated 135km/hr and thats on 255/85 tyres so I would have to say that I can't explain why yours doesn't work.It is booked in next week for a dyno run so stay posted.I have also found my temp gauge falls the thickness of the needle with gas running. Pat

Originally Posted by PAT303

I just had D/gas fitted but it is to early to say anything as I've only used one tank but I have noticed my engine picks up when the gas is supplied and it rev's harder through the gears.The bloke that fitted it has three different sized jets to try .030-.040-.050thou but the .040 seems good as fitted.I have found my diesel usaged hasn't gone down but the top speed has gone up,an indicated 135km/hr and thats on 255/85 tyres so I would have to say that I can't explain why yours doesn't work.It is booked in next week for a dyno run so stay posted.I have also found my temp gauge falls the thickness of the needle with gas running. Pat

Thanks Pat, I will be very interested in your next report. The dyno is really the only way to evaluate the system rigorously, although my stop-watch/GPS method is not too bad.

I started with a 50 jet, and the engine knock increased dramatically. It sounded like a bunch of loose ball barings in the combustion chamber. With a 45 jet the knock was less noticeable but still there. Finally I did a lot of testing with a 20 jet, which returned a gas ratio of between 8.5% and 25%. Maybe my third box is also a dud......I really don't know, I am just fed up with the whole deal.

Paul