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General What's the stock ignition timing map on a 4g63t 1g?

Elpizer2

Probationary Member
15
0
Jul 31, 2022
Miami, Florida
Does anyone has this info? I would like to know it please
 

Kryndon

Proven Member
879
533
Jan 10, 2014
Bulgaria, Europe
From ECMlink's website, here are two screenshots of the High and Low octane timing maps for a 1G:

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Elpizer2

Probationary Member
15
0
Jul 31, 2022
Miami, Florida
What does mean the vertical column? What's the scale?

Horizontal one means RPM but I don't know the other
 

Elpizer2

Probationary Member
15
0
Jul 31, 2022
Miami, Florida
What's the load factor? I mean normally you see vacuum boost or mbar, what's the translation of load factor? How does it work?
 

Elpizer2

Probationary Member
15
0
Jul 31, 2022
Miami, Florida
I don't have ECM Link installed, I just have MAF Translator and stock ECU. So i just can change the efficiency and injection through MAF Translator.

However I want to know what's the stock ignition timing on the stock ECU just to make a better handmade tuning.
 
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Elpizer2

Probationary Member
15
0
Jul 31, 2022
Miami, Florida
Does the OEM ECU without ECMLink do ignition timing over 10 psi?
 
Last edited by a moderator:

Elpizer2

Probationary Member
15
0
Jul 31, 2022
Miami, Florida
What you mean about "way past 10 psi"?
 
Last edited by a moderator:

Elpizer2

Probationary Member
15
0
Jul 31, 2022
Miami, Florida
Yeah.

Does it handle more than 10 psi? What's the ignition timing table
 

1990TSIAWDTALON

Moderator
9,685
5,524
Nov 14, 2013
Independence, Kansas
A 1g timing table is pretty aggressive. Before I had link I could easily run 15lbs of boost.
 

steve

DSM Wiseman
14,865
1,721
Feb 3, 2002
Boulder, Colorado
The MAFT and other tuning solutions that change the airflow values presented to the ECU in effect change the Load the ECU computes and thereby change what the ECU looks up from both the fuel and timing maps.

If you haven't yet, you might want to read the ECU section in the Fuel System Chapter of the 1G Technical Information Manual. https://www.dsmtuners.com/threads/1g-dsm-1990-technical-information-manual.517385/

I forget off hand if the ECU interpolates between cells or not here (I know it interpolates between the high and low maps based on it's perceived fuel quality) and what it does once you go off the edge of the map, but as many of us know it will continue running until the load exceeds the fuel cut threshold and then you hit a brick wall.
 

Kryndon

Proven Member
879
533
Jan 10, 2014
Bulgaria, Europe
The MAFT and other tuning solutions that change the airflow values presented to the ECU in effect change the Load the ECU computes and thereby change what the ECU looks up from both the fuel and timing maps.

If you haven't yet, you might want to read the ECU section in the Fuel System Chapter of the 1G Technical Information Manual. https://www.dsmtuners.com/threads/1g-dsm-1990-technical-information-manual.517385/

I forget off hand if the ECU interpolates between cells or not here (I know it interpolates between the high and low maps based on it's perceived fuel quality) and what it does once you go off the edge of the map, but as many of us know it will continue running until the load exceeds the fuel cut threshold and then you hit a brick wall.
The ECU definitely interpolates between adjacent AFR and Timing cells, in all directions. This is why some people prefer to set for example 11 degrees of timing in all the cells ranging from 4500 RPM and 1.5 Load to 8000 RPM and 2.5 Load, if that makes sense. That way no matter what, the ECU is going to be giving you the demanded 11 degrees of timing. Same applies for the AFR table. It's not the most efficient way to do it but it works.

Also on my 2G stock ECU, my boost cut (technically fuel cut) was at 22 psi on a 16G so that was quite a good margin the Mitsu engineers have programmed into these ECUs. Easily getting 300 crank with bolt ons on stock ECU albeit WOT AFRs always pegged the awful 9.8 : 1 fuel air ratio. The 1G settings seem to be way more aggressive in timing so I would assume he would be seeing way more knock and therefore timing retard and power loss before he hits fuel cut especially on 10 psi.
 

1990TSIAWDTALON

Moderator
9,685
5,524
Nov 14, 2013
Independence, Kansas
I agree on the 1g maps. I always start with one less aggressive (2g base files) but the OP is stock so he has no choice.
 

steve

DSM Wiseman
14,865
1,721
Feb 3, 2002
Boulder, Colorado
Do you know how can I reflash the stock ECU? No ECM

1G ECU's do not have flash memory. They have their software either in masked ROM which is hard coded when the chip is made or in a EPROM which requires external hardware to program the bits and UV light to erase the whole chip.

DSMLink/ECMLink replaces that EPROM with a board that has flash/EEPROM storage and their logic to program it.

There are other devices that are EPROM emulators being used to reprogram the ECU software on the fly but you need to have a solid understanding of how the ECU software works to know what/where to change. The 98/99 2g ECUs are flash based but you still need to know what to change to use them and they don't work with the 1G harness.
 

bastarddsm

15+ Year Contributor
5,480
1,309
Aug 26, 2003
Mendota, Illinois
1G ECU's do not have flash memory. They have their software either in masked ROM which is hard coded when the chip is made or in a EPROM which requires external hardware to program the bits and UV light to erase the whole chip.

DSMLink/ECMLink replaces that EPROM with a board that has flash/EEPROM storage and their logic to program it.

There are other devices that are EPROM emulators being used to reprogram the ECU software on the fly but you need to have a solid understanding of how the ECU software works to know what/where to change. The 98/99 2g ECUs are flash based but you still need to know what to change to use them and they don't work with the 1G harness.
Steve, when you hit the last load row timing is static in "load" it can still move in rpm if you are not at 7000+ That why kylet etal did the double load map back in like '03ish, and I figured out how to use the map sensor to do it off of boost directly back in '10.

OP you might join up on dsmecu.com you might find better help there. Most of the OG's here that know about this stuff have long left. this was all hashed out on the ecu multi yahoo group back in the early oughts. Around here that kinda stuff was a bad word and you got told to get dsm link and move on.
 

steve

DSM Wiseman
14,865
1,721
Feb 3, 2002
Boulder, Colorado
It's 10+ years since most of us played with the code so I couldn't remember 100%.
Speaking of dsmecu.com, I haven't been able to reach it for almost as long. The DNS records for it are long gone.

Around here that kinda stuff was a bad word and you got told to get dsm link and move on.

I don't remember this site being hostile to discussing code modifications, some people were, and the drama caused site issues that no one needed.
 

bastarddsm

15+ Year Contributor
5,480
1,309
Aug 26, 2003
Mendota, Illinois
It's 10+ years since most of us played with the code so I couldn't remember 100%.
Speaking of dsmecu.com, I haven't been able to reach it for almost as long. The DNS records for it are long gone.



I don't remember this site being hostile to discussing code modifications, some people were, and the drama caused site issues that no one needed.
I just got to dsmecu.com on my phone idk if there is anything past the login screen though.

Afair there was a group on here that was very vocal and negative to chip burning and such. Even still today one can't hardly get help on something basic like. 2g maf 550s and afc without being told the have to buy link.
 
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