Instead of N75, can we call it Wastegate control / duty cycle? :D
IMRC should be Intake Manifold Runner Control. Don't know what it is..

Hi Alex,
I have looked at your file finally.

At this point I can tell you that rail pressure precontrol value is not your problem
(RPM freak also told you that a lot before than me).

I am not sure if i am looking your last version of the bin in the progress,
but the one I am looking at will cause a problems you are facing right now.

I suggest you put your precontrol map to stock and solve this problem where it really is.
I also looked at your TL and it is not increased a lot and that can not cause the problems you are facing (considering your hardware is ok).

You have to understand the impact with different limiters (there is your answer).

Think like this (this is an example):
There is always deviation in requested rail pressure and if you request 1350 you will also sometimes achieve 1405 or something like this in some moments...
then your engine will stop, your precontrol valve will go to 0%...and then think what is responsible for that.

The file is far away from done so there could be more reasons for your problems as well.

Hope this helps.

Latest bin here post1521#p1521
I worked on this pressure thing yesterday and I found out some of the things you just said.

I struggle to understand all those limiters :(
And I don't know whick limiter shuts down the engine..

I'll post the work I've done yesterday later..

Ok, so I found out what admin just said by doing some tests...
Pressure gets a lot higher than requested, before returning to requested. So if it reaches 1500bar the ECU shuts down the engine..
I tried to recalibrate precontrol valve, but that can't solve the problem.. It can only be recalibrated to accomodate higher IQ and higher pressure.
I decided to request 1450bar, but to shape the request curve so that it doesn't request it suddenly.
That is because, if you are at 800bar, and request 1450 suddenly, precontrol valve will close up to 98% :shock: and will open again when you reach requested pressure. The problem here is, everything happens really fast!! With the valve closed 98% you will get 1450bar fast, but you will go higher than 1450 because there is a small amount of time when ecu detects 1450 and opens the valve. The valve will still be too closed for a few moments, and that will get pressure higher.
1500 bar, engine stops, enf of story.

Look

Now, I lowered requested pressure and limiters to 1430 and with updated precontrol valve map, and better shaped pressure request, ENGINE NEVER STOPS! :D
Of course deviation is still there! I logged the car for 2 hours and I can tell pressure gets to 1490bar ! but then it decreases to a steady state somewhere between 1420 and 1430.

You can see from the remap that I am going for IQ 70mm3 :D
I updated somke limiter to fit more than 900mg.
Now I have to get the turbo to do more...

Right now my IQ gets limited to 65 - 66 because there's not enough air..
At least the car doesn't smoke.
I know that people say not to rely on MAF because its reading oscillates too much..
well I can say that mine doesn't! Maybe becase it's new :D 'cause I broke the old one while cleaning it, so be careful :!:

Alex.T wrote:Instead of N75, can we call it Wastegate control / duty cycle? :D
IMRC should be Intake Manifold Runner Control. Don't know what it is..

N75....yes OK wastegate control or VNT control on mine.
IMRC..yes to people like me it the swirl valve or butterfly that sits in the inlet manifold.
Theres is two channels into the engine.
Closing the valve forces the airflow through one channel.
Opening the valve allows both channels to be used for max airflow.

You need swirl for optimimum burning of the fuel at part throttle.
Theres onyl so much air a single channel can flow though.
You need the valve fully open at full throttle obviously.

Its a bit like a throttle plate at the end of the day except it only shuts down 50% of the airflow instead of 95+% like a petrol.
I have seen some competely disable it and have it open all the time.

So is it better to tune the precontrol at steady state or full throttle ?
ie. just enough to give you the desired rail pressure steady state and then maybe add on a few % to allow for full throttle
or tweek at full throttle to eliminate the deviation from requested.

Relic wrote:So is it better to tune the precontrol at steady state or full throttle ?

There's no tuning on precontrol..
rail pressure precontrol is all about steady state. like it was said before, it's an input for the PID loop.
you may leave precontrol stock and it will work ok.
I'll give you an example to understand why i wanted to recalibrate it:
at 2000 rpm and 1300 bar, precontrol map says 36%
BUT logging the car and running it steady at 2000rpm while requesting 1300bar you can see the actual duty cycle is about 50%.
I think this is because my high pressure pump has fed the engine for almost 250.000km which is A LOT.
It may not work as new, so the valve has to be more closed to reach the same pressure.
From what I could experience, I can say that if precontrol map is calibrated well, deviation will be smaller, because PID has less work to do. Maybe admin can confirm this theory of mine.

Relic wrote:tweek at full throttle to eliminate the deviation from requested.

You cannot eliminate deviation. Why do you think Peugeot put a 1500bar sensor if requested is only 1350? ;)
As I said, there's NO tuning on this map, but you have to understand it, along with the high pressure system, in order to tune pressure and other things...
I'm not saying I understand it ! I'm just getting into it :D

Ok... makes more sense now especially when you talk of component wear may require tweeking.
I thought the duty gave you the rail pressure like a standard pressure regulator.
Open the pressure relief too much (duty) and the rail pressure drops as too much fuel is returned to the tank.
Close the relief too much and rail pressure climbs.

I also thought PID only cut in if the rail pressure error was too much (ie the duty wasnt right to give you the required pressure)

Limiters are limiting things, that's only job of that.
Now think (Alex) how close do you want to have it near the desired pressure... - one more hint for you ;)

Tuning precontrol is needed when making extreme tune. Or deviation detected.
This map is tricky and you really have to know how it works and impacts the engine running.

Tuning precontrol needs different conditions not only steady, full throttle but more conditions.

It is not so simple.