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Hello all, I have this question for many will seem obvious but for me it is....
I read that if I increase the values for IQ therefore I will have an increase of the turbo pressure due to the greater amount of exhaust gas, it is true, so what?
It seems plausible as a thing, and if it was true I have to consider and calculate the increase in turbo pressure in function of what?
hello,I'm sorry, which are the values iq?
an increase in diesel fuel is injected leads to an increase of pressioine due to the increase of the exhaust gas.so automatically recalculated everything.........
sportraxxx the iq is the amount of fuel injected at each cycle.
It depends on whether the management of the turbo is happening in closed or open loop.
In the first case, the ecu tries to maintain the set pressure value in the map.
In the second case is set to a value in the map of the VGT independent of pressure but dependent on the IQ and the rpm.
Usually the map VGT is calibrated up to a certain IQ.
The transition from open loop to closed is managed by some of the curves with hysteresis that mark the transition from one management to another
thank you Frank...
there is a glossary where you can read all these acronyms ...some are known..some others not
like, for example, closed-loop and open......
thanks
In the case of edc15 vag, which I'm studying to start with, you speak of open or closed loop? as I can understand it to regulate me and not do damage?
Still grazieeee!
this thing is more noticeable with cars equipped with fixed geometry turbine...Quote:
Originally Written by MrcBtr93
if, instead, the mountain of the vgt, the ecu still managed not to "piccare" too much pressure to the turbo..
then it depends on case to case
The transition from open loop to closed loop is handled by the ecu and, I believe, is always present.Quote:
Originally Written by MrcBtr93
The open loop is used to manage a sort of effect of an overboost, the map that refers to this management is the map that to output the percentage of the valve and the input has the IQ and Rpm. One of the pressiione has the same input but of course that is output from the pressure-aim to maintain
I don't know how to say thank you, you were really fantastic Munro and Sportraxxx!
*Franco75: you mean maybe N75 duty cycle? many thanks also to you..
unfortunately I am a beginner like you....Quote:
Originally Written by MrcBtr93
First question : according to what decides the ecu to take account of the objective map turbo and when the vgt ?Quote:
Originally Written by franco75
Second : knowing most the family edc16 fiat group, I have never read of this, closed and open loop. There is also on these ecu's or is the prerogative of other families type vag? Sorry but this is a topic that I do not know and I would like to study
I confirm,to me, are interested in..
there are hysteresis curves according to rpm to select the mode of management. Are maps, threshold of IQ, if they exceed or fall the value of the curve is the switch mode open or closed loop.
In practice, if a certain number of laps is injected with an IQ higher than a curve is used, the open loop effect and an overboost),
when the flow rate drops below another curve is used to capture a closed loop, meaning the ECU "chases" the set point of the map turbo.
Yes, hello, I also noticed I this phenomenon to the diagnosis, in particular, it seems that up to a certain ****s pressure, the ecu follows the preset values in the map vgt, in particular with the engine that does not require much torque.. practical Example at 1800 rpm with the original map in the crowds the opening vgt is as set by the map, in fact, exceeds 100 mbar, about the pressure value of the turbo-set in the homonymous map in fez see it as "pressure lens"
Franco, you present these curves of hysteresis to which you refer or is it your deduction??Quote:
Originally Written by franco75
no, this is not my deduction, mail a sample file and we can see them
Might not be map pressure threshold in which if the value differs by a certain time from the one place in the map dedicated to the turbo pressure by pass the map vgt to control it through a sort of feedback mechanism, electronic as from feedback from the MAP so that it holds the value the more close as possible to the set?
However I in my jtdm 16v that has the edc 16 c39 (euro 4 with swirl) an overboost I have ever read in the various log
perhaps I have explained badly, sorry.
Are two neighboring curves, in function of the rpm is set to an IQ, if you exceed the IQ of the first curve switches to openloop, if it falls below the IQ of the second curve goes to the closedloop.
*made83, what do you mean, you don't see an overboost diagnosis?
That the pressure does not differ never more than that pre-set in the pressure table in relation to rpm and iq, part I repeat in the operations with very little torque, but I think what you might mean an overboost as sonnpressioni under half a bar. However, I do not I'm telling you that nonnhai reason only that I do not understand in that way, since there is already the map pressure in relation to iq and rpm there may be another map (the one to which you refer you), which is used to bypass the common taking into account the same values crossed, I don't know if I can explain myself
Sorry Made83, according to you, the map VGT that gives you the percentage of opening of the geometry in function of rpm and iq what should you serve?
The operation of the map vgt is clear, if you have done to me this question means that I am not made it clear enough, I'm only asking for the values at which the map is based of the hysteresis of the which thou hast spoken, to pass the management of the turbo on the map vgt at the turbo pressure.
it is not a map but the two curves. In function of the spins from an output value of the threshold IQ
Be post screenhot of these curves
screenshot sorry