Reduction in consumption: theory and application on JTDm

[ghibli]

Hi guys,

whereas, I mean, on average, mechanical and technical, but pochissmo of electronic engine management, I have some questions between the terico, and the application that have no answer.
I have had in the past a GPunto 1.3 90 bhp of the first generation, with a remap to improve the delivery to the netherlands (which was... non-existent ori) and for the containment of consumption.

Today I am considering the purchase of a 159 1.9 JTDm (120 or 150 hp), imagining to adopt a remap able to increase the performance (at least not ? this priority?), but bens? to improve the fuel consumption.

Delivery from "my" theory: the fuel consumption of a car depends on hundreds of factors, including: aerodynamics, the front section, the efficiency of the transmission, spacing, gear ratios, fluid dynamics of the engine, type of fuel, mechanical efficiency of the engine/transmission/transmission, paths, "foot" driver... so many things that will affect you in every way and the consumption, even with a map "perfect".
If a machine "requires" 20 hp to go 100 per hour, for the various friction and aerodynamic resistances, and the efficiency and fluid dynamics meccancia of the engine does not change, the consumption will be? always that (this ? at least my theory). This supports my thesis, the fact practical that my GP remapped, in fact, had consumption the best. By cdb... but what ? normal... but from the full to the full, net of kilometres, I would say that the changes remained within as induced by different driving style or different location (less than 50 miles between full and full). Then ok... c'? the history of the greater torque at lower rpm, best guidabilit? and then "pressure pedal lower" and, consequently, lower consumption (not I open this topic,I'm not fully convinced, since? that couple "coast" diesel...but lasicamo by a moment at this point that you do not ? the focus of my discussion).

Now, of course the oil consumption contribute different factors, and vice versa "controllable" with the map. For example, a motor "advance" in the injection tends, in general, to consume less (of course within certain limits). Or the possibility? to eliminate the pre-injections (at least in certain circles) or post injections of the multijet engines (as an example), certainly favours a cut in consumption.

And here I come to my question: from what little I understand, when you remap it works by varying the rail pressure, the pressure of the turbine, the map of the throttle... but I don't know if you also intervenes on advance, on the possibility? cut the pre-and post-injections, or other factors that really "cut" consumption.
Who has experience with this engine or experience generic on rimappe made in this way (if possible) could give me some enlightenment?

:-)

Thanks
Ghibli

[ghibli]

... guys, any comment??

questions that are too trivial?

sorry... I understand that maybe... is a p? "surface"...

[voglioimparare]

hello,already working on the torque limiters,on apressione of the rail and on the advances(I do it often to reduce fuel consumption) to gain enough in terms of power consumption. already the fact of having more torque at the same rpm so you don't sink into a passing or not to sink the foot, translated into words, pavere, less energy consumption. hello

[ghibli]

Thanks a lot voglioimparare.

Dicamo that, for a purely theoretical (I am still far from the remap), I was pleased to understand if "over" to what you write to me ? can, at least theoretically, do more?, also intervening on the logic of pre-and postiniezioni.
I have never read a map in my life, so I wonder: ? "simple" work on pre-and post-injections, or becomes very complicated compared to the other parameters that you have me listing more? on?

Thanks so much to all of those will be able to answer,
soon,
Ghibli

[SandroMarciano]

with the proper knowledge, through the map, you can reach all the engine parameters, including preiniezioni, the post, the angles of the start, etc etc.. how this translates into increases or less efficiency ? all to see...

Also the same can be said "less pressure on the pedal, less consumption" ? one theory is absurd, why? at the end of the fuel injected one ?...

[ghibli]

Thanks SandroMarciano...

the answer ? exhaustive for the theoretical aspect, and I have to tell you that the explanation that you give me on the topic of "pressure pedal", I agree in full... even if c'? pi? pair it down, according to me, that couple is out of the oil-injected...
However, I would not turn on this discussion, since? I see it already? often treated and triggering a very different opinion...

In practice, ? then enough "simple" taglaire pre-injections and postiniezioni, or otherwise "play"?

THANKS!

[SandroMarciano]

for those who know the logic of management, ? easy to play, but do not believe it is as simple as the reduction in consumption.

[ghibli]

I imagine that in practice it is not "simple" the riduziuone.
But from the point of view purely theoretical, at least, based on shared concepts on the technique of this engine, it seems to me that the pre-injection serves to reduce the ruvidit? of operation and to generate the first burst in the room, "starting" how then susseguito from the main injection. "feel" these two "moments" contribute both to produce performance.

Always "sesnazione", the fact that you cut the post injections (from the full-bodied needed to rebuild, to the pi? read to reduce pollution), should help to contain the consumption, not creating per se performance.

Have you tried to do tests like that?
Or semplifico too the question?

[SandroMarciano]

I mainly worked on the JTD, then only 1 preiniezione: calado the value of the consumption increase a lot, the machine becomes heavy and you have to almost always keep the gas on the accelerator.
Increasing it improves both ****monitoring of performance at both ****llo consumption, unfortunately for? vibrates as you increase.

With regard to the post injections if you have the dpf you're forced to keep it... if ? been removed, however, the regeneration will be? been deleted in the ecu, and with the strategy of regeneration also postiniezioni...

[ghibli]

...referring to your first part of message, I'll ask you: by decreasing the entity? of the pre-injection quantity? fuel injected, you have also varied the advance of the ineizione main? As far as I know, all engines emisisonati are deferred (the guide becomes heavy, the engine is lazy at increasing rpm, the fuel consumption increase equal to the amount of? of heat to be disposed of with radiators), but probably ****llo prestaizonale the pre-injection standard (quantity?) helps to compensate for the delay of the injection, encouraging performance decent, and the emissions (what of the pollutant is being produced with the pre-injection then is "withdrawn" in the room by the combustion of the injection main).

I think and I assume that it will reduce (not eliminate) the entity? of the pre-injection maintaining the same advance for this, and then anticipate a little the main should save ", within certain limits," the goat and the cabbage. Certainly ? functional anticipate the main to improve performance and reduce power consumption.
Certain that the operation of the motor should become a pi? rough, and this ? typical injection "too much" anticipated, and this, in my humble opinion, ? the reason for that goes to increase the vibration.

As far as the post injection, I can not answer, since? for the moment I am only doing the reasoning. The machine does not have it yet. From what I read here, it seems to me that if "eliminate" the DPF and put a emulator for the ecu, you dont delete n? post. n? regeneration. While if you delete in the ecu, you eliminate the regenerations but not the postiniezioni (this probably depends from map to map).

I report to you from the last one (but you probably know better than me) that on the multijet, there are two pre-injections and the main. Probably the work on those two in terms of time and bring makes the thing even more? complicated on the JTD, but potentially better advantageous....

[SandroMarciano]

Then you have written so much and not likely to succeed? to answer you all...
I tried to reduce the preiniezione is to increase it by varying the advance of the main, I made your same ideas, however, in practice the fuel consumption and performance ? always better to increase it (even if they are exaggerating, you get the beat of the engine), and of course, working on the advance of the main (which, according to me, that is, the rule so important to the consumption and delivery).

The elimination of the regenerations for many years now it is only from the control unit, eliminating the management dpf and the postiniezioni that serve for its regeneration.

I also worked on the mjet2 170 on preiniezioni, however ? well pi? complex and having the dpf you have many more? variables, for which ? difficult to see the difference between before and after the change. Anyway, on that engine, the PI1 is always working, while the PI2 only at very low rpm, typically up to 2000, probably to reduce vibration...

[ghibli]

ok, so... if you wish "to generalize," you could say that (I am referring to the 1.9 JTDm 120 or 150):
- physical removal of the DPF and the ecu to avoid regenerations and also post injections;
- increase pre-injection in the bosom of the deal? diesel fuel is injected;
- advance of the main injection;
- total closure of the EGR;

Should all of them together to reduce their consumption. Correct?

Of course, it remains a question of why? increase the preinizione decreases the consumption... but perhaps it is the mysteries of fluid dynamics of the air mixture (fuel/oxygen... or the fact that poor preiniezione with injection main "normal" generates a condition that is not ideal to take maximum advantage of the fuel (probably induced by the compression ratio tends to be "low" compared to Diesel).

What do you think?

[Exelion1986]

as you said in the first post there are several factors that contribute to the consumption of a car, most of which cannot be influenced by the average user (aerodynamic resistance, the performance of the transmission...), while others (inflation pressure of the tires, the fact that you do not hold 50 kg of useless stuff in the trunk...)
putting the hand to the mapping you can? also intervene in other ways, or the possibility? to vary the operation of the engine, and the only thing that matters ? the efficiency of the motor itself, that can? improve or worsen depending on the intervention
also in this case we have many types of engine performance, many of which are congenital and are not editable via the map (mechanical efficiency, for example)
in fact, according to me, the returns on which we dwell, are two: that of burning and that of cycle indicator
the first tells us in practice "good," burning the fuel, while the second indicates how much energy (derived from the combustion), we can take advantage of, considering the fact that the motor does not operate according to a cycle
by altering some of the parameters of the mapping, we can have variations of one or both of the yields in the examination
by increasing the pressure of the rail, for example, we will have a better atomization of the fuel and, consequently, an improvement in the combustion
playing instead on the advances we're going to vary the diagram the pressure/volume loop (by moving the peak pressure), and, therefore, the performance of cycle indicator, but potentially also the combustion efficiency because, if you go out of range, the diesel fuel can't burn well
the preiniezioni serve to "prepare" the combustion chamber of the main injection, increasing the pressure and temperature of the air (in the diesel fuel is hard to ignite)
it goes from the s? in this way, the main charge brucer? definitely the best (the best combustion efficiency), with a consequent decrease in the consumption
the postiniezioni, however, happen in the phase of completion (almost at the end of combustion) with the purpose of reducing the pollutants, allowing you to complete the chemical reactions regarding the unburned hydrocarbons, or are related to the regeneration of a dpf possible
however, in both cases, the postiniezioni do not contribute to the performance of the engine

[ghibli]

...Here Is Exelion. Then in the concrete what you tap on the map to improve these two yields and reduce to the maximum consumption? The list of the 4 points that I made more in on or the other?

[Exelion1986]

I have to say that I'm still a newbie in practice, at the moment I know only the theories
certainly the elimination of the egr and dpf helps
with regard to the change of the preiniezioni I would say that the speech of SandroMarciano not a fold
going to logic I would say that the advance has its good influence, but personally I can not say how it reacts to the engine depending on how you change it, for now I'm doing tests on a 1.3 (pi? next I should be able to find a guinea pig 1.9) and on the advance and I still have to put his hand calmly
lastly, I would add to your list also the rail pressure, which in theory should help, but reading a p? around the forum I find conflicting opinions on the fact that worth or not to touch this parameter... probably his influence ? very minor compared to the other
the only according to me ? get to do many tests, to understand that weight is of all the various parameters, why? often the transition from theory to practice ? cos? immediate...

[ghibli]

Certainly of the test are the best solution.
Do you know someone who has the interest to get them on one machine (my), where there can be a profitable dialogue in order to find the best possible solution together?
It would be good to locate someone in the area Emilia/Piemonte/Lombardia/Tuscany....

Thanks
G.

[francescosparco]

I'm on a 159 150 hp have managed to reduce the consumption from 9 to 12 per liter. pero according to my best to be careful. sn cars that suffer from very d turbo

[ghibli]

Hey Francis,

you never consumed so well? little already? before the map?
You, ? true, suffer from turbo.