TP load problem

Nistune topics specific to the 6802 cpu

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FrisbeeGTI
 

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TP load problem

Post by FrisbeeGTI »

Hi!
Setup: standard ca16de (compression ratio 10:1) + roots supercharger (max boost about 0.4-0.5 bar under 5000 rpm, haven't gone higher yet) + wmi & intercooler + 1.7 multiplying rising rate FPR + type 1 nistune board.

Problem: I'm trying to expand fuel and ignition maps to cover increased power area. I've got standard CA16DE MAF. At WOT MAF voltage rises, but TP load stays at constant 23552. Acceleration feels just as constant. MAF translation table is between 2.5v - 6.6v. Tried to widen up fuel and timing load scales and tables (88->92 in the beginning) and this seems to work (tracer rises easily to last row at WOT, i have to expand more). I have to lower ignition advance, map is just preliminary.

Is my intake a bit restrictive or is there some bug with MAF voltage/TP load computing? Played earlier with intake restrictor plates to control boost, but now I have no restrictor plates mounted.

My log is as attachment.

EDIT: tried also with load scaling to 88-95-100-105 (last four rows) but when logging drive load scaling stops to 92 and TP load to 23552 and at the same time MAF voltage rises.

Cheers,
FrisbeeGTI
Attachments
logcawmi1.csv
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Matt
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Re: TP load problem

Post by Matt »

Your MAF appears not to read any higher than 5.5V in the log (it is flat lining here (with TP=23552)

Have you increased your Max Load (TP) - TTP MAX tables at all? Its the only thing which could hold TP back... however your MAF is also pegging which is why TP is not increasing further
Attachments
N13_CA16DE.png
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FrisbeeGTI
 

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Re: TP load problem

Post by FrisbeeGTI »

Matt wrote:Your MAF appears not to read any higher than 5.5V in the log (it is flat lining here (with TP=23552)

Have you increased your Max Load (TP) - TTP MAX tables at all? Its the only thing which could hold TP back... however your MAF is also pegging which is why TP is not increasing further
Thanks for this reply.
Yes I have increased my Max Load - TTP Max tables to upper limits.

In the log TP load stays constant 23552 at the same time as MAF voltage rises slowly towards 5.5V. If I understand right, MAF senses more and more air going through, but TP value stays constant. I expanded upper load scale limit first 88->92, then further up. But tracing stops to load scale 92, not going up to 105 for example.

In MAF translation scale value 23552 is in the slot of load scale 92, the MAF voltage at the same spot is a bit over 5 if I remember right. The voltage and load scales continue further. Voltages in MAF translation scale are from 2.5V to 6.5V in this model.

So the car is from 80s...

Is it now so that ECU doesn't understand MAF voltages over 5V (or 5.12V?) and cannot use the whole MAF voltage input scale which comes from MAF?
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Re: TP load problem

Post by Matt »

Looking at that screen grab, around 39-41 seconds into the log I see MAF (blue) pegging at 5.539 and TP (green) limted to 23552 at the same time. I do not see MAF increasing any higher here
TP load stays constant 23552 at the same time as MAF voltage rises slowly towards 5.5V
I'm not seeing that in the log (screenshot above). What timestamp?

Load scale = TP / 256

I think you have hit the limit of that MAF from what I can see
FrisbeeGTI
 

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Re: TP load problem

Post by FrisbeeGTI »

Matt wrote:Looking at that screen grab, around 39-41 seconds into the log I see MAF (blue) pegging at 5.539 and TP (green) limted to 23552 at the same time. I do not see MAF increasing any higher here
TP load stays constant 23552 at the same time as MAF voltage rises slowly towards 5.5V
I'm not seeing that in the log (screenshot above). What timestamp?

Load scale = TP / 256

I think you have hit the limit of that MAF from what I can see
Yes I didn't go to higher revs and voltages here because of detonation risks with this tune.

Between 39.5 and 42.5 secs MAF voltage goes from 5.410V to 5.599V, at the same time TP stays at 23552. So propably MAF is limiting here as you wrote because the ECU doesn't seem to understand voltages over 5.1V.

So if I swap this MAF to a newer, bigger one which gives 1-5V, is it possible to rescale the MAF translation between 2.5V and 5.1V for this ECU and get also lower load scales working right? Or is it easier to use older, bigger high voltage Z31 MAF (2-7V)? Third option could be using a resistor for this MAF voltage and rescale the MAF translation table. Would it be then about 382 ohms (maybe I should use a potentiometer)?

EDIT: the MAF part no is 22680-61A00 (Hitachi). It seems that in Europe it is used in S13 CA18ET, N13 CA16DE CA18DE, B12 CA16DE CA18DE. In USA it is used in S12 CA18ET, KN13 CA16DE CA18DE.
FrisbeeGTI
 

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Re: TP load problem

Post by FrisbeeGTI »

Just wondering differences between MAF VQ table voltage ranges (MAF translation) between models in Nistune.

N13 CA16DE 2.5-6.6V
N13 CA18DE 1.5-6.6V
KN13 CA16DE 0.08-5.1V

Why is that? All of those use this same MAF.
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Re: TP load problem

Post by Matt »

I don't have too much information on these ECUs and only one here (N13 CA16DE 82M00)

N13 CA16DE 82Mxx => KN18 CA18 MAF
N13 CA18DE 02Yxx => KN18 CA18 MAF
KN13 CA18DE 65Mxx => KN18 CA18 MAF

Yes you are right they all use the same MAF

The offset for each is located in the address file:
LEGACY_AFM_OFFSET=1500

You can remove this from the address file. I just measured the MAF line into the ECU and pin 40 on the HD46510 chip on my ECU and there is no voltage translation
Attachments
N13_CA18DE_128_E.adr
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N13_CA16DE_128_E.adr
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Re: TP load problem

Post by Matt »

Using updated address files... Attached is the image showing the standard TP limit at 17664

MAF has limit of 4.8V before it tops out (actually drops)
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N13_pulsar_MAF_limit.png
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Re: TP load problem

Post by Matt »

Unfortunately spent a good part of the day on this one... but with good news

There are four things which set the TP limit on this vehicle:
TTP min (last value in column)
TTP max
AF Limit parameter (added this parameter)
Temperature indexed TP table (used at idle)

For the problem you are seeing you just need to increase the last value in the TP Minimum limit table. I've done this and can increase the maximum load

Whilst I was inside the disassembly for this ECU also added in the short term fuel trim and injection time so you can see some more stuff. Will be available in the next release :D
Attachments
N13_Pulsar_MAF_fixed.png
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FrisbeeGTI
 

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Re: TP load problem

Post by FrisbeeGTI »

Matt wrote:Unfortunately spent a good part of the day on this one... but with good news

There are four things which set the TP limit on this vehicle:
TTP min (last value in column)
TTP max
AF Limit parameter (added this parameter)
Temperature indexed TP table (used at idle)

For the problem you are seeing you just need to increase the last value in the TP Minimum limit table. I've done this and can increase the maximum load

Whilst I was inside the disassembly for this ECU also added in the short term fuel trim and injection time so you can see some more stuff. Will be available in the next release :D
Thanks so much! :lol:
Before I read your message I removed the AFM voltage offset from .adr.

Then uploaded this new tune to the ecu and started the car. MAF translation table VQ was now nicely between 1-5.1v. The car got some throttle at idle, and the max TP value I got was 28672 (that is in the "cold" log). 8) Then warmed up the car and went driving. When the car was warmed up i didn't got TP to rise over 23552 ("warm" log). Maybe that's related to what you wrote. I have to change that TP min table's last row (last value was now 92 as before) and try again. I'll report the result after couple of days.
Attachments
warm-ca16de.csv
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cold-th-ca16de.csv
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Matt
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Re: TP load problem

Post by Matt »

okay let me know how it goes. I wont spent more time looking at the logs in the meantime until you increase that TTPmin table and try it out again
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Re: TP load problem

Post by FrisbeeGTI »

Matt wrote:okay let me know how it goes. I wont spent more time looking at the logs in the meantime until you increase that TTPmin table and try it out again
I raised the last right side row value of TTPmin table to 200 and it works now! at leat tp is not completely straight line at some point. log file is attached

Is it necessary alter also other left side row values of the TTPmin table? noticed some hesitation at lower revs (<2000) when accelerating.
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issue1.csv
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Re: TP load problem

Post by Matt »

You can try it. I only tested the upper RPM levels where you were getting the cut.
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Re: TP load problem

Post by FrisbeeGTI »

The original .ADR file worked very well so that just that LEGACY_AFM_OFFSET line was removed and TP minimum was increased to 255 from RPM 1600 ->

I recommend using the original .ADR for CA16DE with just LEGACY_AFM_OFFSET-line removed (and TP min changed in nistune) because that worked very well and the new .ADR version posted here gave some difficulties with the tune (Fuel and timing load scalings were somehow messed up for example, i don't know why) or maybe I couldn't use it right. There is some oddities in that new .ADR for CA16DE, there is definitions that the car has 6 cylinders for example, maybe some copy-paste related problems.

But thanks Matt for solving this TP load -problem for CA16DE, now it is easier to tune forward with that stock maf and do MAF upgrades easier if needed.
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Re: TP load problem

Post by Matt »

Thats strange, since I thought I only changed about two lines in the address file. See how you go with the next release when the updates come in
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