Thread: isuzu & LPG

bee utye

do you have a 4bd1-t with diesel gas, and do you fit these kits.

I have picked up a second hand kit from a 200tdi, I am going to fit it to my 4bd1-t(aftermarket). Question will it run on the fuel setting from the 200tdi allright, if not is there a guy in north Queensland that tunes them.

Originally Posted by lambrover

Dougle to me it seems abit far fetched that just because you add double the fuel you will double the engine out put and that sounds like the way you are approaching it.

Obviously you need to add sufficient air to burn that double dose of fuel. For this engine we're talking 25-30psi with a good intercooler to burn those injection volumes clean.

But yes burning double the fuel does double the output. Possibly even a little more as engine efficiency can improve a little with higher loads.

No I haven't dyno'd my rover, there aren't any reputable dyno's near me or my travels. If I had a dyno printout I'd happily share, but I don't. Also as you'd probably know dynos can be quite inconsistent
I use a viaduct which was built quite recently and which I know the slope exactly. IMO this is a more realistic test, the only problems are it's located at almost 1000m altitude and I only get one data point.
Here is my data:
2500kg total weight
6.75 deg slope (yes that's 12%).
Velocity 80km/h
RPM 2048 (4th gear)
CdA 1.6m^2
Wind drag 474N
Drive force at wheels 3357N
Power at wheels 74,593 watts

Flywheel torque with 100% efficient drivetrain 347 Nm
Flywheel torque with 70% efficient drivetrain 496 Nm
Flywheel torque with 65% efficient drivetrain 535 Nm

Using other dyno plots as a guide, I think the drivetrain is between 65 and 70% efficient, hence ~520Nm.
Keep in mind this test is done at 950m altitude.

I suspect you're right that none of the people fitting these systems are up with the science (or lack of) behind it. But I'm still hoping one day to find someone that does.

Originally Posted by Dougal

Full of scorn today aren't we?

The airflow of an idling diesel is very easy to quantify, we know the displacement, we know the rpm.
700 rpm on a 3.9L diesel with 80% ve is 1092 l/min
The gas flow was measured at 16 seconds for 1.2 litres. 4.5 l/min.
4.5/1092 = 0.412%.

Max possible error +/- 50%. This 50% includes rpm fluctuation, VE fluctuation, and scatter in measurements.

Final mix could be anywhere from 0.2-0.6%

Since you paid for a dyno tuner to reduce your fuelling you'd hope you weren't melting pistons. What power figures did they come out with?

Yes always full of scorn. And no I didn’t PAY a dyno tuner to back off my fueling. but hay next time I am in wellington maybe I could tune your beast 74KW seems a bit week, numbers usually start at 80kw and move up from there, and as for what my numbers are, well I may post that when I have finished with my playing,

What I cant understand about you Dougal, is that there are thousands of LPG fumigated cars truck and 4x4s in aussie. The government pays for a lot of it! And with Australia’s sue first couture that the lpg fumigation deal isn’t kosher. Add to that, every time LPG and diesel is mentioned you come barging and claiming its a load of rubbish.

now I could be posting what adjustments I have done, what sort of improvements have been made, what worked what didn’t etc but regardless of what I post I am sure you will twist and rubbish it so why should I bother.

For any one who is really interested they can just pm me.

oh by the way your maths, you are missing a couple of things LOL

Originally Posted by lambrover

bee utye

do you have a 4bd1-t with diesel gas, and do you fit these kits.

I have picked up a second hand kit from a 200tdi, I am going to fit it to my 4bd1-t(aftermarket). Question will it run on the fuel setting from the 200tdi allright, if not is there a guy in north Queensland that tunes them.

I'm having dgas fitted tuesday,I have dyno print outs for each change I have made,(first turbo,then intercooler,and last 3" exhaust)when the gas is fitted I'll try to get another one,currently 80kw at wheels.

Originally Posted by clean32

Yes always full of scorn. And no I didn’t PAY a dyno tuner to back off my fueling. but hay next time I am in wellington maybe I could tune your beast 74KW seems a bit week, numbers usually start at 80kw and move up from there, and as for what my numbers are, well I may post that when I have finished with my playing,

What I cant understand about you Dougal, is that there are thousands of LPG fumigated cars truck and 4x4s in aussie. The government pays for a lot of it! And with Australia’s sue first couture that the lpg fumigation deal isn’t kosher. Add to that, every time LPG and diesel is mentioned you come barging and claiming its a load of rubbish.

now I could be posting what adjustments I have done, what sort of improvements have been made, what worked what didn’t etc but regardless of what I post I am sure you will twist and rubbish it so why should I bother.

For any one who is really interested they can just pm me.

oh by the way your maths, you are missing a couple of things LOL

Lets see.

I don't live near wellington, never have.
74kw is not peak power, 74 kw is what I have at the ground at 2000rpm.
Never mentioned rubbish, I just ask questions which people can't seem to answer.
Bee utey said you had a dyno tune done when diesel was reduced. Now you say you haven't. Does anyone know what has been done to your vehicle?

If you have some corrections to my maths, feel free to post them.

Originally Posted by Dougal

What fumigation rates are being used? Owners can only speak of litres of lpg to litres of diesel. Which gives no indication at all of the actual rates being injected. Especially since diesel injection rates at any rpm can vary from nothing to full load while gas injection will be either constant volume flow or at best metered to the air supply which will only change with boost.

Sorry I can help you with a % fumigation value. The equipment I use allows me to adjust gas flow rates to be non-linear to the air flow. i.e none at idle and more at higher RPM. I.E vacuum generated by airflow must exceed a certain amount before gas fuelling starts. I have no way of measuring the real time flow rate as that is not in my development budget. Two simple limit switches control low/high accel flow of gas so there is a sweet spot at which it has the most effect and a region of less effect, then no gas supply at either end. It is simple but it works. The electronic systems have a TPS on the throttle to adjust gas fuelling on atmo cars.

Originally Posted by lambrover

bee utye

do you have a 4bd1-t with diesel gas, and do you fit these kits.

I have picked up a second hand kit from a 200tdi, I am going to fit it to my 4bd1-t(aftermarket). Question will it run on the fuel setting from the 200tdi allright, if not is there a guy in north Queensland that tunes them.

Hi lambrover, I am fitting kits which are different to the others currently on the market so I can't comment on your exact application. However I imagine raising the gas delivery rate should pose no problems to a tuner used to your system.

Originally Posted by Dougal

I see a lot of people focusing on the lpg hose up the intake. But the interesting part is the lpg delivery method doesn't matter in the slightest. All these systems deliver LPG to the air entering the cylinders, the only part that actually matters is the resulting lpg/air mix.

If I find detonation on a cold engine with no intake heating from boost with only 0.4% fumigation. Then surely the allowable rates to avoid detonatoin drop as engine temperature increases and the intake becomes heated from turbo boost.

What fumigation rates are being used? Owners can only speak of litres of lpg to litres of diesel. Which gives no indication at all of the actual rates being injected. Especially since diesel injection rates at any rpm can vary from nothing to full load while gas injection will be either constant volume flow or at best metered to the air supply which will only change with boost.

I'm not asking about customer satisfaction or testimonials. I'm asking specific technical questions which never get answered. We've already got lots of people like Clean32 marvelling over how much better his engine runs while specifically not mentioning the dyno tune that was part of the package.

Big-guy, I haven't insulted anyone in this thead. We do however have a whole post of personal attacks from Clean32 which he then deleted, more ridicule from Clean32 and indeed your appearance in the Isuzu forum with no idea of what an Isuzu engine is capable of.

I'm asking some simple questions, if you can't answer them, feel free to ignore them.

Dougal

I have several friends with Isuzu motors and am currently doing research for another with a 4bbe3.6 or similar.
I am not a fan of big truck donks in little Discos etc but get where the notion comes from and the way these particular engines perform.

I also get that you are trying to dazzle us with techno babble that most will not and want not understand.
Get your old rig converted to gas while you still can, I guarantee you that it will make a big improvement. Do it before the government grabs it and recycles it into little sardine cans.

Ask and discuss as much as you like, don't insult us if you don't have facts.
Your maths on torque sounds impressive but since I am at least not a maths professor, can not validate those outrageous sums.
70 odd kw's and over 500nm, i just don't believe your theory and thats all it is.