mrfred

iTrader: (50)

Updates

May 23, 2008: Added a link towards the end of the post to some additional boost tuning tables.

April 8, 2008: Added instructions for EDM Evo VIII 96530006. Thanks evo828 for creating instructions for this ROM.

Mar 20, 2008: Added instructions for USDM Evo VIII 94170014, 94170015.

Sept 26, 2007: Added instructions for USDM Evo VIII 96420007, 96420008.

Sept 8, 2007: Added instructions for EDM Evo IX 88840016.


Intro

This post outlines some tricks for improving the Evo's load-based boost control system. I also have a thread that shows how to convert over to a direct boost control system.


Supported ROMs

88590015
96940011
96420008
96420007
94170015
94170014
94170008
96530006
88840016


Background

I tried for many months to effectively control boost using the ECU-based boost control system and was never able to obtain predictable results. So, I went looking through the ROM code to try to understand how the boost control system works in detail. I found quite a few new things related to boost control. At the moment, only a few are useful for improving boost control.

1) There are several load variables used by the ECU. The one used by the boost control algorithm is very dependent on air temperature. The dependence is such that it makes the car try to boost higher in hotter weather. Not good. The fix for this is to use a load variable that does not change with intake air temp. Turns out that the 2-byte load variable that everyone logs is the best load variable to use.

2) The WGDC correction algorithm runs on a simple timer between adjustments. (Its a simple PI controller for those who know what that is.) The stock interval is about 0.8-1.0 seconds between adjustments to the WGDC. This interval can be shortened to as little as 0.08 second. By shortening the interval, the ECU will much more rapidly respond to deviations of the load from the target load value (BDEL + BCLO).

3) I have worked out a method for logging load error (difference between target load and actual load).

4) I have worked out a method for logging the WGDC Correction.

With these mods, I've been able to greatly improve boost control. Instructions for tuning the system are at the end of this post.


Instructions for modifying ECUFlash definitions and your ROM

Here are the current instructions for modifying your ROM. Instructions for modifying the EvoScan "Data.xml" file are a little further down. I'll add more ROMs as I have time.

Note: I can only guarantee that these definitions are compatible with ECUFlash 1.30 or below. I have not yet checked compatibility yet with ECUFlash 1.31+.


USDM Evo IX 88590015

Add the following lines to your ROM file:

----- (don't add the "-----")
<table name="Variable for Boost Control" category="Turbo" address="41E12" type="1D" level="1" scaling="Hex16"/>

<table name="WGDC Correction update delay #1" category="Turbo" address="1654" type="1D" level="1" scaling="uint16"/>

<table name="WGDC Correction update delay #2" category="Turbo" address="1656" type="1D" level="1" scaling="uint16"/>

<table name="Load Error RAM Address" category="Turbo" address="41E06" type="1D" level="1" scaling="Hex16"/>

<table name="Load Error RAM Address in Load Error Table" category="Turbo" address="7254" type="1D" level="1" scaling="Hex16"/>

<table name="MUT8A" category="MUT" address="3F0AE" type="1D" level="1" scaling="Hex16"/>

<table name="MUT8B" category="MUT" address="3F0B2" type="1D" level="1" scaling="Hex16"/>
-----

Instructions for ECUFlash

Variable for boost control: Stock will read 6B48. Change it to 6B42. The table is in hex format, so you will have to enter it as 0x6B42

WGDC Correction update delay: Use table #1. Table #2 is for when the vehicle speed exceeds the boost limiting speed. Set the value anywhere from 2 to 10. Each unit is approx 0.08 to 0.1 sec.

The "Load Error RAM Address" and "Load Error RAM Address in Load Error Table" will both read: 69CA. Change both to 6EE2 (again, you'll need to enter it as 0x....)

Change MUT8A will read 6ACD. Change it to 6EE3 (again enter it as 0x....)

Change MUT8B will read 6B41. Change it to 6EE9 (enter it as 0x....)

Save the ROM file and upload it to your ECU. Then go to the instructions below for setting up EvoScan.


USDM Evo VIII 96940011

Add the following lines to your ROM file:

----- (don't add the "-----")
<table name="Variable for Boost Control" category="Turbo" address="204ba" type="1D" level="1" scaling="Hex16"/>

<table name="WGDC Correction interval #1" category="Turbo" address="1654" type="1D" level="1" scaling="uint16"/>

<table name="WGDC Correction interval #2" category="Turbo" address="1656" type="1D" level="1" scaling="uint16"/>

<table name="Load Error RAM Addr" category="Turbo" address="204ae" type="1D" level="1" scaling="Hex16"/>

<table name="Load Error RAM Addr in Load Error Table" category="Turbo" address="5fd2" type="1D" level="1" scaling="Hex16"/>

<table name="MUT8A" category="MUT" address="3F53E" type="1D" level="1" scaling="Hex16"/>

<table name="MUT8A" category="MUT" address="3F542" type="1D" level="1" scaling="Hex16"/>
-----

Instructions for ECUFlash

Variable for boost control: Stock will read 89A0. Change it to 899A. The table is in hex format, so you will have to enter it as 0x899A

WGDC Correction update delay: Use table #1. Table #2 is for when the vehicle speed exceeds the boost limiting speed. Set the value anywhere from 1 to 10. Each unit is approx 0.08 to 0.1 sec.

The "Load Error RAM Address" and "Load Error RAM Address in Load Error Table" will both read: 887A. Change both to 802A (again, you'll need to enter it as 0x....)

Change MUT8A will read 8927. Change it to 802B (again enter it as 0x....)

Change MUT8B will read 8DAB. Change it to 8D2D (again enter it as 0x....)

Save the ROM file and upload it to your ECU. Then go to the instructions below for setting up EvoScan.


USDM Evo VIII 96420007, 96420008

Add the following lines to your ROM file:

----- (don't add the "-----")
<table name="Variable for Boost Control" category="Turbo" address="1f96e" type="1D" level="1" scaling="Hex16"/>

<table name="Load Error RAM Addr" category="Turbo" address="1f962" type="1D" level="1" scaling="Hex16"/>

<table name="Load Error RAM Addr in Boost Error Table" category="Turbo" address="6b0a" type="1D" level="1" scaling="Hex16"/>

<table name="WGDC Correction interval #1" category="Turbo" address="1a54" type="1D" level="1" scaling="uint16"/>

<table name="WGDC Correction interval #2" category="Turbo" address="1a56" type="1D" level="1" scaling="uint16"/>

<table name="MUT8A" category="MUT" address="3a1ca" type="1D" level="1" scaling="Hex16"/>

<table name="MUT8B" category="MUT" address="3a1ce" type="1D" level="1" scaling="Hex16"/>
-----

Instructions for ECUFlash

Variable for boost control: Stock will read 898A. Change it to 8984. The table is in hex format, so you will have to enter it as 0x8984

The "Load Error RAM Address" and "Load Error RAM Address in Load Error Table" will both read: 8866. Change both to 802A (again, you'll need to enter it as 0x....)

WGDC Correction update delay: Use table #1. Table #2 is for when the vehicle speed exceeds the boost limiting speed. Set the value anywhere from 1 to 10. Each unit is approx 0.08 to 0.1 sec.

Change MUT8A will read 8913. Change it to 802B (again enter it as 0x....)

Change MUT8B will read 8D9F. Change it to 8D21 (again enter it as 0x....)

Save the ROM file and upload it to your ECU. Then go to the instructions below for setting up EvoScan.


USDM Evo VIII 94170014, 94170015

Add the following lines to your ROM file:

----- (don't add the "-----")
<table name="Variable for Boost Control" category="Turbo" address="1ee8e" type="1D" level="1" scaling="Hex16"/>

<table name="WGDC Correction interval #1" category="Turbo" address="1a54" type="1D" level="1" scaling="uint16"/>

<table name="WGDC Correction interval #2" category="Turbo" address="1a56" type="1D" level="1" scaling="uint16"/>

<table name="Load Error RAM Addr" category="Turbo" address="1ee82" type="1D" level="1" scaling="Hex16"/>

<table name="Load Error RAM Addr in Load Error Table" category="Turbo" address="69a8" type="1D" level="1" scaling="Hex16"/>

<table name="MUT8A" category="MUT" address="38382" type="1D" level="1" scaling="Hex16"/>

<table name="MUT8B" category="MUT" address="38386" type="1D" level="1" scaling="Hex16"/>
-----

Instructions for ECUFlash

Variable for boost control: Stock will read 8962. Change it to 895C. The table is in hex format, so you will have to enter it as 0x895C

WGDC Correction update delay: Use table #1. Table #2 is for when the vehicle speed exceeds the boost limiting speed. Set the value anywhere from 1 to 10. Each unit is approx 0.08 to 0.1 sec.

The "Load Error RAM Address" and "Load Error RAM Address in Load Error Table" will both read: 883E. Change both to 8026 (again, you'll need to enter it as 0x....)

Change MUT8A will read 88EB. Change it to 8027 (again enter it as 0x....)

Change MUT8B will read 8D49. Change it to 8CD9 (again enter it as 0x....)

Save the ROM file and upload it to your ECU. Then go to the instructions below for setting up EvoScan.


USDM Evo VIII 94170008

Add the following lines to your ROM file:

----- (don't add the "-----")
<table name="Variable for Boost Control" category="Turbo" address="1ee8e" type="1D" level="1" scaling="Hex16"/>

<table name="WGDC Correction interval #1" category="Turbo" address="1a54" type="1D" level="1" scaling="uint16"/>

<table name="WGDC Correction interval #2" category="Turbo" address="1a56" type="1D" level="1" scaling="uint16"/>

<table name="Load Error RAM Addr" category="Turbo" address="1ee82" type="1D" level="1" scaling="Hex16"/>

<table name="Load Error RAM Addr in Load Error Table" category="Turbo" address="6754" type="1D" level="1" scaling="Hex16"/>

<table name="MUT8A" category="MUT" address="3828a" type="1D" level="1" scaling="Hex16"/>

<table name="MUT8B" category="MUT" address="3828e" type="1D" level="1" scaling="Hex16"/>
-----

Instructions for ECUFlash

Variable for boost control: Stock will read 8962. Change it to 895C. The table is in hex format, so you will have to enter it as 0x895C

WGDC Correction update delay: Use table #1. Table #2 is for when the vehicle speed exceeds the boost limiting speed. Set the value anywhere from 1 to 10. Each unit is approx 0.08 to 0.1 sec.

The "Load Error RAM Address" and "Load Error RAM Address in Load Error Table" will both read: 883E. Change both to 8026 (again, you'll need to enter it as 0x....)

Change MUT8A will read 88EB. Change it to 8027 (again enter it as 0x....)

Change MUT8B will read 8D49. Change it to 8CD9 (again enter it as 0x....)

Save the ROM file and upload it to your ECU. Then go to the instructions below for setting up EvoScan.


EDM Evo VIII 96530006

Add the following lines to your ROM file:

----- (don't add the "-----")
<table name="Variable for Boost Control" category="Turbo" address="2025e" type="1D" level="1" scaling="Hex16"/>

<table name="Load Error RAM Addr" category="Turbo" address="20252" type="1D" level="1" scaling="Hex16"/>

<table name="Load Error RAM Addr in Boost Error Table" category="Turbo" address="6bfa" type="1D" level="1" scaling="Hex16"/>

<table name="WGDC Correction interval #1" category="Turbo" address="1a54" type="1D" level="1" scaling="uint16"/>

<table name="WGDC Correction interval #2" category="Turbo" address="1a56" type="1D" level="1" scaling="uint16"/>

<table name="MUT8A" category="MUT" address="3642a" type="1D" level="1" scaling="Hex16"/>

<table name="MUT8B" category="MUT" address="3642E" type="1D" level="1" scaling="Hex16"/>
-----

Instructions for ECUFlash

Variable for boost control: Stock will read 898A. Change it to 8984. The table is in hex format, so you will have to enter it as 0x8984

The "Load Error RAM Address" and "Load Error RAM Address in Load Error Table" will both read: 8866. Change both to 802A (again, you'll need to enter it as 0x....)

WGDC Correction update delay: Use table #1. Table #2 is for when the vehicle speed exceeds the boost limiting speed. Set the value anywhere from 1 to 10. Each unit is approx 0.08 to 0.1 sec.

Change MUT8A will read 8913. Change it to 802B (again enter it as 0x....)

Change MUT8B will read 8D9F. Change it to 8D21 (again enter it as 0x....)

Save the ROM file and upload it to your ECU. Then go to the instructions below for setting up EvoScan.


EDM Evo IX 88840016

Add the following lines to your ROM file:

----- (don't add the "-----")
<table name="Variable for Boost Control" category="Turbo" address="408B2" type="1D" level="1" scaling="Hex16"/>

<table name="WGDC Correction update delay #1" category="Turbo" address="1654" type="1D" level="1" scaling="uint16"/>

<table name="WGDC Correction update delay #2" category="Turbo" address="1656" type="1D" level="1" scaling="uint16"/>

<table name="Load Error RAM Address" category="Turbo" address="408A6" type="1D" level="1" scaling="Hex16"/>

<table name="Load Error RAM Address in Load Error Table" category="Turbo" address="735C" type="1D" level="1" scaling="Hex16"/>

<table name="MUT8A" category="MUT" address="37A22" type="1D" level="1" scaling="Hex16"/>

<table name="MUT8B" category="MUT" address="37A26" type="1D" level="1" scaling="Hex16"/>
-----

Instructions for ECUFlash

Variable for boost control: Stock will read 6B28. Change it to 6B22. The table is in hex format, so you will have to enter it as 0x6B22

WGDC Correction update delay: Use table #1. Table #2 is for when the vehicle speed exceeds the boost limiting speed. Set the value anywhere from 1 to 10. Each unit is approx 0.08 to 0.1 sec.

The "Load Error RAM Address" and "Load Error RAM Address in Load Error Table" will both read: 69B2. Change both to 6ECE (again, you'll need to enter it as 0x....)

Change MUT8A will read 6AAD. Change it to 6ECF (again enter it as 0x....)

Change MUT8B will read 6B21. Change it to 6EC5 (enter it as 0x....)

Save the ROM file and upload it to your ECU. Then go to the instructions below for setting up EvoScan.


Instructions for EvoScan (0.99)

Add the following entry to your EvoScan "Data.xml" file:

-----
<DataListItem DataLog="Y" Color="" Display="Load Error" LogReference="LoadError" RequestID="8A" Eval="0.15625*x-20" Unit="load" MetricEval="" MetricUnit="" ResponseBytes="1" GaugeMin="-25" GaugeMax="25" ChartMin="-25" ChartMax="25" ScalingFactor="1" Notes=""/>
<DataListItem DataLog="Y" Color="" Display="WGDC Correction" LogReference="WGDCCorr" RequestID="8B" Eval="0.5*x-64" Unit="WGDC%" MetricEval="" MetricUnit="" ResponseBytes="1" GaugeMin="-50" GaugeMax="50" ChartMin="-50" ChartMax="50" ScalingFactor="1" Notes=""/>
-----

Save the Data.xml file, and you're ready to log Load Error and WGDC Correction.


Additional Tables

Some additional boost tuning tables can be found here:

https://www.evolutionm.net/forums/sh...d.php?t=333479


Tuning Instructions

After making the mods described above to your ROM, my suggestions for tuning this system are as follows:

A) Zero out the right hand column of the TBEC table. With this column zeroed out, the ECU will not apply any corrections to the WGDC. Using WOT 3rd gear runs, adjust the Baseline WGDC (aka Max WGDC) tables until the boost curve is where you want it. It could take 10+ adjustments (with a run after each adjustment) to get this worked out. By starting with this step, it will be much easier for the ECU to hold the target load curve under in different gears and driving conditions.

B) Start with a WGDC Correction Interval to "2".

C) Set the TBEC table to the following values:

-20.0 0.0
-17.5 0.0
-15.0 0.0
-12.5 1.0
-10.0 2.0
-7.5 1.5
-5.0 1.0
-2.5 0.5
0.0 0.0
2.5 -0.5
5.0 -1.0
7.5 -1.5
10.0 -2.0
12.5 -2.0
15.0 -4.0
17.5 -8.0
19.8 -12.0

Both the WGDC Correction Interval and the TBEC table can be adjusted as needed to tune the system to your liking.

TouringBubble

iTrader: (2)

You are THE MAN! Now, if we could only get the stock solenoid to work similar to the Greddy EBC which holds 100% duty until a certain PSI is reached, regardless of RPM.

mrfred

iTrader: (50)

I'll be looking into that possibility.

dudical26

iTrader: (17)

WOW, this is going to be awesome once it is all sorted out.

Amazing work, thanks so much!!

supeazn

iTrader: (3)

sweet ...

tkklemann

iTrader: (6)

Well fark me in the goat ****, ths would be awesome... Damit I wish I knew how to do all this stuff so I could contribute too...

mrfred

iTrader: (50)

ok. I was able to log target load (BDEL + BCLO), load error, and WGDC correction. See below. I plotted them compared to "load fuel/timing" and "load boost". I also plotted "load boost" minu "target load" to compare to the load error calced by the ECU. Some interesting points:

1) The logged target load value is exactly equal to the target load table data found in ECUFlash.

2) EDIT: The calculation of the load error in the code is actually pretty easy to follow. I had screwed up though is the scaling of the load error calculated by the ECU. After scaling it properly, the load error calculated by the ECU very nicely matches the load error I calculated from "load boost" - "target load".

I had forgotten that I had zeroed out my WGDC upward correction, so there is nothing to show there.

Anyhow, tomorrow I will substitute "load from fuel/timing" in place of "load boost" in the load error calculation routine, and then there should be some interesting WGDC correction data when I do some logs.

tephra

iTrader: (6)

good work dude!

can you log the actually boost as well? or is your car not JDM MAP equiped?

RazorLab

iTrader: (8)

I've seen the 03 rom do this until a certain load. It is unique in this as the other roms do not do this from what I have seen.

I'll upload some log shots tomorrow if I find time.

jcsbanks

Could the load error(logged) be an integrator? (just from the looks of it)

chmodlf

iTrader: (19)

mrfred is the guy who figured out how to make the JDM MAP work on US evos. He can definately log boost!

mrfred

iTrader: (50)

Turns out that the load error calc in the code is very simple and I had screwed up my scaling of load error into load units. After scaling it correctly, I get excellent agreement between my calculated load error and the ECU load error. I replotted the data in post #7.

tephra

iTrader: (6)

yes - I know - it wasn't such a question about whether he CAN or not, just he should so we can see if the graphs correlate to load

mrfred

iTrader: (50)

I may have some graphs like that today.

mrfred

iTrader: (50)

Hey Folks, it took longer than I had hoped, but I have found some items that will make it much easier to tune the ECU-based boost control system.

1) I have determined that the WGDC correction algorithm operates on a simple timer, and I have found the delay time setting that sets interval between WGDC corrections! (IMHO, this is huge.) The stock value is 10. The scaling appears to be 1 unit = 0.08 sec, so 10 units is about 0.8 seconds. The min value I would recommend trying is 2.

2) I have the address for the load variable that is used in the WGDC correction routine. If you like, you can set it to the same 2-byte load variable that you are logging (which turns out to be a very consistent load variable).

3) I found the RAM address for the WGDC correction value, so it can be logged. The address if FFFF6EE8.

At the moment, I only have time to post the table entries for the 88590015 Evo IX ROM. I probably won't have time to post the entries for other ROMs until next week. Here are the entries to add to your 88590015 ROM:

----- (don't add the "-----")
<table name="Load Variable for Boost Control" category="Turbo" address="41E12" type="1D" level="1" scaling="Hex16"/>

<table name="WGDC Correction update delay #1" category="Turbo" address="1654" type="1D" level="1" scaling="uint16"/>

<table name="WGDC Correction update delay #2" category="Turbo" address="1656" type="1D" level="1" scaling="uint16"/>

<table name="MUT8A" category="MUT" address="3F0AE" type="1D" level="1" scaling="Hex16"/>
-----

Instructions for modifying table values in ECUFlash

Load variable for boost control: Stock will read 6B48. You can try changing it to 6B42. The table is in hex, so you will have to enter it as 0x6B42

WGDC Correction update delay: Use table #1. Table #2 is for when the vehicle speed exceeds the boost limiting speed. Set the value anywhere from 2 to 10.

WGDC Correction logging: MUT8A will read 6ACD. Change it to: 6EE9. This table is also in hex, so you'll have to enter it as 0x6EE9. In EvoScan, you'll have to add a new entry to log ID "8A". The scaling for WGDCC is "x/2". The correction logged in EvoScan be in WGDC units. My suggestion would be to copy and paste your WGDC correction entry, and then change the name and log ID.

EDIT: If you are going to log the WGDC Correction, you're going to find that its not going to match your expected response in warm weather. This is because the stock load variable for boost control runs significantly below the 2-byte load variable that everyone is logging when the weather is warm/hot. If you really want to get a handle on ECU-based boost control, set the load variable to 6B42

There's also several other tidbits that I've found, but they're not important for WGDC control at the moment.

Have fun.