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Author Topic: a3 3.2 022906032CB ME7.1.1G advice  (Read 82638 times)
Mikhail
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« Reply #30 on: August 02, 2016, 01:51:01 AM »

Only other option is underscale the hell out of the MAF, but even then you will have issues.

Not directly related to this, but question to gurus is, that when table reading goes over max x or y axis, does the ecu read the max x or y from the table at that case?



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gman86
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« Reply #31 on: August 02, 2016, 02:40:34 AM »

Not directly related to this, but question to gurus is, that when table reading goes over max x or y axis, does the ecu read the max x or y from the table at that case?


Yes, it'll ride the last values.
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Mikhail
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« Reply #32 on: August 03, 2016, 02:30:23 AM »

Next question to gurus: dsg map tuner said, that he can't rise the clutch pressure (more than certain amount?) and therefore the ecu has to give the real torque to to the dsg to achieve good clutch pressures. Is this ecu send torque possible to alter by some variable or is only chance to change the range of the load?
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prj
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« Reply #33 on: August 03, 2016, 05:01:20 AM »

Everything is possible.
But there are few who are able to do it.
The DSG and the ECU map has to be done by the same person, that's the only way you are going to get it to work right.
Showing the correct torque on this ECU is not possible with only map modification in a turbocharged application. Some ECU code paths have to be patched.

I have some time in September if you decide you want it mapped Smiley
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Mikhail
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« Reply #34 on: August 03, 2016, 06:40:07 AM »

Everything is possible.
But there are few who are able to do it.
The DSG and the ECU map has to be done by the same person, that's the only way you are going to get it to work right.
Showing the correct torque on this ECU is not possible with only map modification in a turbocharged application. Some ECU code paths have to be patched.

I have some time in September if you decide you want it mapped Smiley
I think, that I try my self first. Have to look, that is it possible to do a repeater to the can-bus after engine, by which would repeat all messages but change the ecu send torque value by boost pressure or something.
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prj
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« Reply #35 on: August 03, 2016, 07:59:11 AM »

I think, that I try my self first. Have to look, that is it possible to do a repeater to the can-bus after engine, by which would repeat all messages but change the ecu send torque value by boost pressure or something.
If you have a problem with simply sending the correct torque I can not imagine what problems you will have with tuning the ECU - for example throttle control that knows nothing about boost and so on.
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jameswalker
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« Reply #36 on: August 08, 2016, 02:12:02 PM »

I think, that I try my self first. Have to look, that is it possible to do a repeater to the can-bus after engine, by which would repeat all messages but change the ecu send torque value by boost pressure or something.

Before I decided to attack the ECU, I did exactly this. I made a CAN interface that parsed messages on the fly and "corrected" the values sent. I spent hours and hours down this path. I gained total control of the CAN bus yet still did not achieve what you wanted to; increase the DSG clamping pressure.

I managed to verify that the DSG was receiving my altered values yet it still was not happy. The relationship between torque demand, actual torque, and many other torques, is critical and MUST be done by the ECU. It is far more complex than you think right now.

By all means go down the same path I did and I will help you with as much as I know, but really you are better off spending time on the ECU instead.
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jameswalker
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« Reply #37 on: August 08, 2016, 02:14:18 PM »

ASM mod needs to be done and ECU converted to single lambda... I can do this for a fee if needed.
Do not fit lambdas pre-turbo they won't last.

For correct conversion you need:
100% load patch
single lambda patch
boost control patch

And then lots of cal stuff has to be modified...
Definitely not something a "noob" can do...

Could you explain why those 3 things are needed for the conversion? I currently run 2 lambdas (well, 4 if you could the narrowband post cats) so am interested to see what you say. Secondly what do you mean by 100% load patch and boost patch. Thanks,
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nyet
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« Reply #38 on: August 08, 2016, 02:52:53 PM »

Could you explain why those 3 things are needed for the conversion? I currently run 2 lambdas (well, 4 if you could the narrowband post cats) so am interested to see what you say. Secondly what do you mean by 100% load patch and boost patch. Thanks,

They really should need no explanation; all are needed for a properly functioning torque model and accurate fueling.

The idea that you can just slap FI on a NA motor and not worry about the ECU is pure folly.... I have no idea why this persists. I suppose partly out of ignorance and partly out of wishful thinking.
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ME7.1 tuning guide (READ FIRST)
ECUx Plot
ME7Sum checksum checker/corrrector for ME7.x

Please do not ask me for tunes. I'm here to help people make their own.

Do not PM me technical questions! Please, ask all questions on the forums! Doing so will ensure the next person with the same issue gets the opportunity to learn from your experience.
jameswalker
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« Reply #39 on: August 09, 2016, 03:37:31 AM »

They really should need no explanation; all are needed for a properly functioning torque model and accurate fueling.

The idea that you can just slap FI on a NA motor and not worry about the ECU is pure folly.... I have no idea why this persists. I suppose partly out of ignorance and partly out of wishful thinking.

This wasn't really the response I was after. I am not saying there is no need to worry about the ECU. I am worried! Hence I have asked those questions. I am not questioning if they should be there or not, I am questioning their relevance.

How is 1 lambda probe better for fuelling than 2?

WHAT is the 100% load patch that was mentioned?

WHAT is the "boost control patch".

What is changed in each of the above and why. I am interested in WHY, I am not interested in taking shortcuts.
« Last Edit: August 09, 2016, 03:40:15 AM by jameswalker » Logged
nubcake
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« Reply #40 on: August 09, 2016, 04:08:53 AM »

These are the kind of questions that require a million of other questions answered. Like "why does the plane fly?"

In short:
You're going with single turbo and a single downpipe - so why install 2 lambdas? It can be done this way too, sure, but why?
>100 load patch is needed to make motronic "accept" boost pressure.
"Boost control patch" is needed to regulate part throttle conditions and not have the "on-off" car.
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vwaudiguy
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« Reply #41 on: August 09, 2016, 07:04:41 AM »

I think people have tried to put both lambdas in the same pipe, but ended up having bank to bank trim issues.
« Last Edit: August 09, 2016, 10:14:34 PM by vwaudiguy » Logged

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prj
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« Reply #42 on: August 09, 2016, 01:18:25 PM »

I think people have tried to put both lambdas in the same pipe, but end up have bank to bank trim.issues.

Precisely, they trim away from each other, so you end up with -25% on one bank 25% on other and then limp mode.
100% load - the ecu won't let you request more load, because it is NA and 100% means atmospheric.
Boost control is really twofold - the ECU needs to know when it can go WOT and when to use the throttle. It needs to know pre-tb pressure or at least an approximation to control the throttle correctly, and it needs to control boost somehow.

But really - read the FR and search for SY_TURBO, it will answer a lot of your questions.
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Mikhail
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« Reply #43 on: August 09, 2016, 10:11:32 PM »

I managed to verify that the DSG was receiving my altered values yet it still was not happy. The relationship between torque demand, actual torque, and many other torques, is critical and MUST be done by the ECU. It is far more complex than you think right now.

By all means go down the same path I did and I will help you with as much as I know, but really you are better off spending time on the ECU instead.
Ok. Have you had any findings so far which you could share?
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jameswalker
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« Reply #44 on: August 10, 2016, 03:47:52 AM »

Ok. Have you had any findings so far which you could share?

I am not entirely sure what you are after. But if you want to experiment, here is my breakdown of the CAN command:

outgoing.data.bytes[0] // throttle pedal status (idle / depressed)
outgoing.data.bytes[1] // Engine torque 0 to 410NM (as reported in VCDS)
outgoing.data.bytes[2] // rpm LSB
outgoing.data.bytes[3] // rpm MSB

outgoing.data.bytes[4] // unknown
outgoing.data.bytes[5] // accelerator pedal % 0-100
outgoing.data.bytes[6] // engine torque (loss) 0-416NM
outgoing.data.bytes[7] // unknown

Also bear in mind the DSG is more complex than set and forget. It replies to the ECU. For example it tells the engine to reduce torque so that it can change gear. You can prove this because it will refuse to upshift if you hold the torque at 100%, for example.

There are various behaviors like this, that you sort of get a feel for during experimentation.

Despite my analysis, I failed to achieve what I wanted to and have now chosen to investigate the situation from the ECU side.
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