Goal ZERO LAG

[asdone]

Hello all,
I'm trying to make a map that has as its primary objective the reduction of the Lag of response when you press the accelerator to the bottom when the car actually starts to develop the required power.
At the moment I am not interested to particular increments of CV.


The component pi? slow to get there in the scheme ? definitely the turbo, in detail? because they affect the actuators of variable geometry and wastegate?
According to you ? just try to keep the turbo always under pressure to always have enough air to provide the maximum diesel? In this way for? the values of the advance for that amount? diesel fuel would be incorrect since the reaction with pi? the air ? pi? fast. And then the engine would do more? hard to compress and expel air at each cycle if this ? this in qty more.
In the case of the presence of the lambda probe, the maps lambda act as a limiter or as a goal?

How do you usually do in order to improve the response?

[Exelion1986]

the wastegate does not affect the lag ? only a limitation to the maximum pressure
the variable geometry, on the contrary, serves to improve the response while not renouncing the air flow rate to the high
in practice, on the basis of the position of the flaps, ? how to have turbines of different sizes in a, as by directing the flow of the exhaust gas can? prefer the speed? of the same (turbine pi? small, response ir? quick) or the flow (turbine pi? great, higher flow rate, pi? power top)

with regard to the electronics for? I can not help, do not have enough expert

[asdone]

Ok, but the wastegate to the electronic control should affect why? change the quantity? air is that it is discarded, in this view, depending on its position should change how fast it goes in the pressure and how much ? the higher the peak pressure. Or am I wrong?

[Exelion1986]

you are the ones to control the electronic influence on the peak pressure, allowing an overboost, but finch? the turbo is not ? pressure remains closed, therefore does not work in the transitional
pi? important as an influence, if at all, ? the pop off, but ? present only on the petrol and not the diesel

[passion engines]

Hello, it processes the turbo with a variable geometry, but westgate is a pressure, would start immediately, with a max turbo and then decrease according to the calibration of the westgate.... currently for me ? the best solution

[asdone]

So I take off my many problems :)
But in the case of variable geometry, the time of opening/closing the mechanical of the palette ? considerable?
Example: at the time of release, and I want to resume, which pedal to the bottom right, about the same as they would put the blades to move to the slope?

[passion engines]

then I think that you know how it works your of westgate and geometry, and with this mod ? always + ready the turbine , of course, you have to first calibrate them well, especially in that the pressure must get to the maximum, then say lag zero, I'll take it for good, for? I can tell you I my that decrease a lot.

[munro]

So I take off my many problems :)
But in the case of variable geometry, the time of opening/closing the mechanical of the palette ? considerable?
Example: at the time of release, and I want to resume, which pedal to the bottom right, about the same as they would put the blades to move to the slope?
the attack of the diagnosis or a pressure gauge and tirendi for yourself what puts us at the turbo to give you all lap ressure that st? in the map turbo....
remember that if you give the more fuel you have the more exhaust gas, and then the lag is reduced even more....
even if, however, talk about lag on turbines with variable geometry ? an understatement...
as already 1000 rpm or a little more able to provide already 0.5 bar of boost or more...
this pressure is sometimes limited in the map turbo or maps n75 duty cycle to avoid having peaks unwanted pressure, low speed, and to avoid stressing unnecessarily the clutch wheelies too sudden torque...
to change with the wg pressure I do not go to because at the time of release, especially at high rpm v? to close the vgt doing significantly raise the back pressure in the exhaust is very harmful on the springs and exhaust valves that precisely when this becomes excessive tend to "float" without going back to closing with all the problems that arise...
bad combustion,loss of volumetric efficiency,the rise of egt,lost performance,unwanted contacts the valve piston,etc., etc.....then each f? how better to believe but the fact remains that sapendp how and where to intervene in the map a vgt "depression" and a hundred times better than a pressure....IMHO

[passion engines]

[munro]

passion motors...no ? theory but and elementary physics....an engine basically ? a "air pump" if at 4000-4500 rpm it suddenly releases the gas and it's true that the injectors smetterrano to inject but ? also true that the exhaust gas does not decrease as you....because, however, the engine in "release" continues to swallow air and logically to eject it...if you caps this process of expulsion of air and exhaust gases still have a piccata of back pressure...guaranteed...if you don't believe me, stick a pressure gauge with a copper tube on the collectors and check out yourself what I mean...the management vgt ori a "depression" to work around this problem in the release opens fully and the shovels, and drain as much as possible in the gas...if not, given the ratio A/r of the exhaust a tiny turbine with vgt vanes closed is what I affirm in the other post...
however, I have noticed that on a punto 1.9 jtd with a vgt turbine pressure seals in the manifold lasted nothing...implemented the n75 in the ecu and managed in the depression the problem ? risolto.....ergo....

[passion engines]

Munro and I have no doubt about what you write, I just wanted to tell you that the mod that tries Asdone not ? so exasperated...

[asdone]

I don't want a mod exasperated, but I wanted to learn more? possible so I'm glad to exchange opinions!
The values in the map I confirm what was said by munro, that is, that at the time of release the vgt tends to stay open, and then to try to keep up the pressure, should I try to leave completely open the vgt also with 0 diesel (with the consequent risk of spikes).
C'? some special logic to be adopted in the map to avoid the spikes without sacrificing speed? rise of the pressure?

[munro]

attacks the diagnosis and make a log, or mount a pressure gauge turbo and realize for yourself at what rpm do you feel it a p? slower to give you pressure....only in that way you can figure out where to actually act.....know for? that is what you are looking for you ? a "sophistication" that requires a lot of time in tests....you could try starting to increase slightly the n75 duty cycle exactly where and the bottom to try to keep slightly more closed the vgt in such a way as not to slow down the turbine...if you're still not satisfied with the results, you may try to intervene on the pid control going to increase the intervention time by tapping the factor The controls mentioned....when going to close too the vgt is likely to have all of the contraindications that I wrote before...
repeat this for? are tests that require countless attempts.....

[checchitotiralaleva]

I would be a little afraid to touch the gains of the PID controller of the boost control. Even without touching the nervous P proportional... there might be the risk of incurring instability? of the control. With a VGT available to me it would seem rather a good idea to raise the map of the boost to the partial points of departure of the transient). To make it start loading.

I would also add not to overlook the introduction of the diesel engine is not ? of all a slave to the air flow as the gas, in fact, has the chance? to work with the lambda variables, then the price of some sfumazzata, therefore, could be to speed up the transient even relaxing, for example, the map smoke (decrease map of the lambda minimum).
In addition, pi? diesel = pi? energy to the turbo = the ascent of the boost more? quick...

Ciaooo

[asdone]

For? you may only change the speed? intervention, which would increase the boost maps by limiting the peaks. Or am I wrong? Someone of you has already? tried it this way?

[checchitotiralaleva]

To increase the speed? intervention you have to upset the control of the boost, and then act on the parameters of the control... if I remember well so much more? a control ? responsive (hard in the analogy, the mass-spring-damper) so much more? ? pi? ? easily cause oscillations...

[asdone]

I understood, in the case of oscillations I guess you're talking about fractions of a second, hardly I could record them with a log, but I notice from the disbursement. Let? some test and I'll know how it behaves!

[checchitotiralaleva]

and in general, the frequency of the oscillations of the boost that you may have, they are relatives of the frequency of the discharges, which for a 4-cylinder engine should be: rpm * 2 / 60 [Hz]
Hello
let us know!

[Exelion1986]

is the formula ? correct
a motor cycle occurs every two revolutions of the shaft in a 4-stroke, cio? 4 pi radians
being a 4-cylinder is a discharge every 4 pi/4 cio? every pi radians
the conversion between rpm and rad/s ?: rad/s = 2*pi*rpm/60
then the frequency ? f = rad/s / pi rad = 2*rpm/60 [1/s] the cio? [Hz]

[munro]

and grace as aplicate the calculation of the frequency on a pid control??

[Exelion1986]

I'm sorry but for this you have to wait for someone else... in mechanical me the cable, but anything electronic

[munro]

just for informational purposes, and you're talking with a mechanic with 25 years of experience.....and that 3-4 years this part engages with a p? of electronics applied to vehicles...
I asked,simply,as with the calculation of the frequency according to you can? be/will help in the modification of a pid control?

[checchitotiralaleva]

Non pu? be of help.
It was only a consideration in order to understand if a normal instrument diy of dignosi would have had sufficient frequency to catch the oscillations of the pressure in the intake manifold that may occur as a result of an incorrect change de the gains of the PID controller.

[checchitotiralaleva]

Sorry not meant to be a message in pi? but I just wanted to add one to the previous message, but I can't change it...

To change the calibration of the PID you need to find a maneuver repeatable, modify, and observe how he behaves the signal of the controlled quantity to vary the gain is changed.
reached the quickness? implementing best you have to compromise with the regolabilit? control to prevent oscillations in the steady state.

In essence I don't toccherei... better to give diesel transient (map smoke) and raise the target boost in the points of arrival of the maneuvers you want to improve.

[asdone]

Question, but if the user asks for 60 mm diesel and the fumes map in the context of rpm and air limits to 40 mm, the target boost that will come from? the bed will be? however, at 60 mm?

[checchitotiralaleva]

No, but in the

[checchitotiralaleva]

No maps always enters into the introduction of the current, which is limited. However, if the restriction map smoke ? active means that you are during a transient, and the boost target ? still not been achieved.

[asdone]

Clear as always :)

[checchitotiralaleva]

Thanks!
You have news on your tests?

Ciaooo