What does it do?
The DieselGas Sequential II gas injection system utilises a sophisticated electronic control unit (ECU) that controls the injection of LPG into mechanical and electronic diesel engines, whether stationary or mobile, turbocharged or naturally aspirated. The system works on any diesel engine running in any application - 4WD, commercial, road or rail transport, power generation or irrigation. It also suits two-stroke variants.
Fitting a boost gauge to monitor turbo
operation on a Nissan Patrol during a
power run on the dyno
The system operates by simultaneously burning diesel with a small quantity of gas, resulting in a more efficient burn rate of 95%-98% (most diesel engines achieve around 75-80%). This increase in efficiency results in less diesel being used to create the same outcome (essentially, more bang for your buck). This combustion efficiency refers not so much to the amount of diesel actually burnt, but to
when it is burnt.
Best of all, no engine modification is required, the system is non-invasive, operates completely independently and is self tuning.
How does it work?
High-pressure liquid petroleum gas (LPG) is converted to a high pressure useable gas by a converter/regulator. The gas flow into the engine is controlled by a high pressure
vapour injector operating at 250Hz. This gas is injected directly into the inlet manifold with the incoming air.
An electronic control unit (ECU) controls the rate of injection, optimising performance and ensuring safety. Manifold pressure, throttle position, engine temperature, exhaust temperature and engine speed are all monitored. The ECU then adjusts the gas flow depending on engine load and driver demand. The amount of gas injected (or the ‘gas map’) is completely self learnt - the ECU adapts to your driving style. The system can be monitored and adjusted via a laptop if necessary. This allows a large degree of flexibility to adjust the system to suit your requirements.
A new feature of DieselGas Sequential II is that it actually
allows gas flow at idle. For vehicles that spend a lot of time idling, a
substantial amount of diesel can be saved by substituting LPG for extended idle periods. This is only possible with the accuracy offered by a vapour injector. Incidentally, this also reduces engine idle noise.
Throttle status is constantly monitored - every time your foot comes off gas flow is stopped
instantly and completely. The injection rate is calculated ten times per second, and any change is made in time for the next rotation of the crankshaft! By ceasing gas injection for each gearchange, every time brakes are applied and when coasting downhill,
LPG consumption is reduced, therefore extending your gas range without sacrificing performance.
The system can be switched on and off (if ever necessary) via a dash mounted switch. If gas is unavailable, or you run out before a refuelling station, it is not necessary to switch the system off. Instead, the system will shut itself down when the LPG tank is empty. Since the diesel injection system is not modified, the vehicle will simply run on diesel as it did before the system was fitted. Once you have refilled, DieselGas Sequential II will automatically come back on.
Effect on Engine Efficiency
Coming soon is an essay on this topic that will explain, in chemical and mechanical engineering terms, why DieselGas achieves the results it does.
Data Logging and Diagnostics
Another new feature is
inbuilt data logging and fault diagnostics. The ECU constantly logs the last 250 hours of driving - all parameters are recorded in real time. Each ignition cycle, each time the gas is switched on, each time the LPG tank is refilled, plus every signal from each sensor are all constantly logged (engine speed, load, coolant and exhaust temperature and throttle position), allowing
in depth fault diagnosis.
Using this data we can also exmine the actual vehicle operating conditions to check the performance of the system, ensuring you are achieving maximum benefits.
The ECU will log faults with sensors and flash a warning to the driver, informing you there is a problem and that DieselGas has been shut down. DieselGas Sequential II can also be
diagnosed via an internet connection - we can interrogate your ECU from anywhere in the world!
As a courtesy a service reminder is also programmed to alert the driver when the 12 month service is due.
Range and fuel savings
As a result of the increased efficiency created by burning the diesel where it produces maximum benefit, less diesel is now required to travel each kilometre, therefore extending the range travelled on each tank of diesel. Or, to look at it another way, the same amount of diesel will deliver more power and torque.
Documented evidence indicates net fuel cost savings of 10-20% are achieved running on either bio-diesel or normal diesel. For further explanation, see
Economy section.
Power and Torque
DieselGas Sequential II will increase power and torque by up to 20% (and often more). This power increase is due not only to the increased combustion efficiency, but also the LPG itself produces power as it burns. The ECU will
automatically change from an economical to power setting as the driver or conditions demand.
This extra power is instantly noticeable from the moment the system is turned on. However, as the engine clears carbon deposits over time it is not unusual for the advantages of the system to increase.
A power run with a 4.2 Patrol on the Dyno
The power and torque increase applies over the whole rev range. Turbo lag is all but eliminated, and engine noise and vibration is dramatically reduced all the way through to maximum revs. The driver will notice fewer gear changes and higher average speeds, particularly on hills and when towing.
See
Vehicles section for examples of power gains.
Engine Life
For those of you with experience with LPG cars, you would know the engine oil stays much, much cleaner between oil changes. LPG engines, when stripped, are almost spotless internally. On the other hand, petrol engines and (in particular) diesel engines are quite dirty internally. After an oil change, the new oil quickly becomes black again.
In a diesel engine, this black stain is soot.
Soot is the result of incomplete combustion (the same as any wood fire stove) This soot (which is actually carbon) gathers in the combustion chambers, lining the top of the pistons, the injectors, the glow plugs and the valves. Some stays there and builds up into thick carbon deposits that must be scraped away when the engine is stripped. Some is blown into the exhaust manifold, coating the inside of the exhaust pipe or blown out the back as black smoke. The rest is washed off the cylinder walls by the engine oil, thus contaminating it and turning it black. This is why engine oil filtration is critical in diesels.
Heavily contaminated diesel sump oil
after 5000 km
With enough carbon contamination,
oil soon loses its ability to lubricate and clean properly, leaving abrasive deposits on critical components and allowing further carbon build-up. This causes engine wear - hence the need to change the engine oil on a regular basis. Anyone who changes their own oil will tell you that with diesels, the oil becomes very black, very quickly. This indicates that the oil is doing its job, but it is also already breaking down and losing its effectiveness, long before the next oil change is due.
Going back to our LPG engine, since LPG is a clean burning gas it does not leave soot behind. This is why the engine and oil are staying cleaner for longer. With DieselGas Sequential II, cleanliness is achieved slightly differently. The gas introduced acts as a catalyst, encouraging complete diesel combustion. This means less soot (a lot less soot) which, in turn, means the oil stays cleaner. Now, if the oil is staying cleaner, that means it is not carrying as much contamination, and is therefore doing its job better and for longer. The upshot is reduced engine wear between oil changes and over the life of the engine (which is extended as a result).
Engine
operating temperatures are constantly monitored. If an overheat is detected, the ECU will reduce or completely shut off gas flow. Exhaust gas temperatures are also monitored, and again the gas flow is shut down if high EGTs are reached (regardless of the cause).
Reply With QuoteOriginally Posted by EchiDna
http://www.dieselgas.com.au/landrover.htmThanks, EchiDna!
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