95REGF150
10+ Year Contributor
- 447
- 242
- Mar 7, 2012
-
Elk Grove,
California
Well I'm happy to report that after a lot of time and effort we now have working factory boost control for the H8 blackbox ECU's with ECUFlash. First a little background:
As any of you who use ECUFlash know, Ceddy did a huge amount of work back in the day and created Ceddymods (His site has recently gone down but I hope that he will have it back up soon). This has been a huge resource for over a decade and offers us some of the things that the Evo guys get with Tephramods such as an SD option, Bigger Maps, 2 Step, etc. And while Ceddy did a great job on this, some of his work went unfinished when he moved on to other things and one of those things is Electronic Boost Control. If you look in the Ceddymods .XML you can see he was planning and had the beginnings of a layout for Boost by Gear but never got to it.
If any of you know how Ceddy and Tephra start out finding all the maps and such, they use a method called disassembly, it uses software to turn the meaningless 1's and 0's that we copy from the ECU in to a ROM file into something called assembly language. And if youv'e ever done computer coding with a high level language you will know that reading low level assembly language is 10 times harder than that. It's full on reverse software engineering taking a program a team of other people wrote and trying to figure it out blind just from processor instructions. I say that so you know the amount of effort people like Ceddy and Tephra had to put in to their ROM's and why no further development of the Eclipse black box has been done since Ceddy moved on.
So that's where I come in. I'm not a Ceddy but I do have some experience with high level coding and computers and after using CeddyMods for years I always wanted some type of Boost Control just like the Evo guys have. So a few years ago I sent Ceddy an email and being the great guy he is he sent me his disassembly file with his notes from his original work. It does'nt have the special code he added for the CeddyMods specific stuff but everything that he defined that was there from the factory is there so it gave me somewhere to start.
After many long hours of trial and error and testing I found that our cars have almost identical code to what was used in the Evo 5 & 6 and very similar code to what Mitsu used in the Evo 7 & 8. So if you want to learn in detail how the boost control works on our cars I recommend reading the boost control section of the below guide for the Evo 8 as it is the same for the Eclipse.
STEP BY STEP GUIDE:
1. As you will see in that guide the first thing you have to do is ditch your stock Boost Control Solenoid usually reffered to as the BCS get a GM 3 port BCS part number 214474 and plumb it per the below diagram:
The real AC Delco solenoid is currently less than $50 on Amazon
2. DO NOT DRIVE THE CAR WITHOUT TUNING (See Wastegate RPM Control Below). The largest difference between the Eclipse and the Evo 8 is that our system was designed around 100% duty cycle of the BCS. Meaning it was at 100% duty cycle almost all the time. They used the BCS on the Eclipse to drop the boost DOWN at spool and cut the torque spike which is why so many of us deleted the OEM BCS. But now you have installed the 3 port which is completely different. The 3 port at 100% duty cycle will not open the wastegate at all:
3. In order to get boost control working you will have to use my .XML for EcuFlash to get the correct tables. Go to the below directory on your computer:
C:\Program Files (x86)\OpenECU\EcuFlash\rommetadata\mitsubishi\eclipse
Then replace the 20550011.XML with the 2055011 1998 USDM Eclips GST MT - Boost Control.XML I have attached. (It would not let me upload a .XML so I changed it to a .TXT text file. When you put it in the folder make sure you change the .TXT file extension back to .XML)
4. Open ECUFlash and open your CeddyMods ROM. The WasteGate section will now have all the maps I have defined:
5. Tune It! We are going to be setting up our tables just like the Evo 8 so if you haven't please go read the Merlin's tuning guide I posted above so you can understand what I'm doing.
Boost Desired Engine Load (BDEL) & Boost Control Offset (BCO):
The BDEL table is the target load that the boost control is trying to hit. Meaning if you spool to 15psi and hit 160 load but this table is set for 200 load the ECU will start adding duty cycle to the solenoid and upping the boost to try and hit the load value. This table max's out at 160 load so to be able to do bigger loads Mitsu used an "adder" value which is the BCO. So the target load is
BDEL Table Lookup + BCO Value = Target Load
Below you can see the original BDEL table with my "tuned" table on the right:
Factory BCO is set to 40:
You can see they target max load the entire time except during spool and just after spool to keep the torque spike down. So the factory target load is 160 + 40 = 200% which by no coincidence is the same as the factory boost cut. Which shows how the factory BCS was designed to never be able to boost the car harder just drop the boost down some. For me I was targeting 250 Load so I changed my BCO value to 90 and put the BDEL table at a full 160. You can make both BDEL tables 1 and 2 the same but it only uses the first map unless you have map switching set up.
Base Wastegate Duty Cycle:
This table is exactly as the title says. Its the starting duty cycle of the solenoid per RPM. If you leave it set at 100% during spool it can slightly improve your spool time by keeping the wastegate from popping early. You want to set this LOW to start out with and bring it up slowly after making some runs to see what duty cycle correlates to how much boost. I start at 25% duty cycle. Factory map left starting tune map right:
Again set both 1&2 maps to the same values.
Turbo Boost Error Correction
This map works off of the error calculated from the BDEL table above. Meaning you start out in the pull and it takes Target Load - Actual Load = Error. Then depending on that error + or - out of this table it selects a value to add to the duty cycle.
So if my target load is 250% and at 25% base duty cycle I am hitting 230% load it will be 250 - 230 = 20% error and it will add 7.5% every cycle to the solenoid duty cycle.
Max Total Upward Correction
Exactly as it says this limits the amount of upward error correction that can be added on. So from our example say we are at 25% duty cycle and not hitting 250 load. The error correction will add 7.5% duty cycle the first time and now we are at 32.5% duty cycle. If the load is still not at 250 the error correction can only add 2.5% more duty cycle for a total of 35% duty cycle at full throttle according to this map:
This keeps you from over boosting if there is a boost leak or some other issue that causes you load to be high.
WasteGate Airflow Control
This map is not found in the Evo 8 and is unique to the Eclipse. This is the airflow limit for boost control. If the MAF Hz goes above the top value, the ECU will drop the wastegate duty cycle to 0 as a protective measure. It will not reengage boost control until the Hz level falls below the bottom number
WasteGate Octane Control
This map is also unique to the Eclipse and not found on the Evo. It is the Octane level limit for boost control. If the Octane Level falls below the top value, the ECU will drop the wastegate duty cycle to 0 as a protective measure. It will not reengage boost control until the Octane level rises above the bottom number.
WasteGate RPM Control
This map can be found in the Evo but it works slightly differently in our cars. The Evo was setup for actual boost control from the factory so outside of the control range it defaults to 0% duty cycle. For us since the BCS was designed around max duty cycle outside of the control range the wastegate duty cycle defaults to 100% duty cycle. So for the bottom 2 numbers "Deactivate Rising" and "Deactivate Falling" you want to set those to 8000 or whatever your rev limit is to make sure boost control does not shut off and go to 100% duty mid pull. Let me reiterate that - IF YOU DO NOT CHANGE THIS THE WASTEGATE WILL NOT OPEN ABOVE 3812 RPM - Sorry for the all caps but don't want anyone blowing their engine up at max boost.
Alright so that's it. Go out and make some pulls and get your Base Duty Cycle and Desired Load setup and enjoy factory Mitsubishi boost control.
I did not do any custom coding for this all of these maps are there from the factory. So this .XML will work with any 2055 ROM including the BigMaps and SD ROMS. Huge thanks to Ceddy for sending me his disassembly without that this would not have been possible and he did not have todo that. Awesome guy.
As any of you who use ECUFlash know, Ceddy did a huge amount of work back in the day and created Ceddymods (His site has recently gone down but I hope that he will have it back up soon). This has been a huge resource for over a decade and offers us some of the things that the Evo guys get with Tephramods such as an SD option, Bigger Maps, 2 Step, etc. And while Ceddy did a great job on this, some of his work went unfinished when he moved on to other things and one of those things is Electronic Boost Control. If you look in the Ceddymods .XML you can see he was planning and had the beginnings of a layout for Boost by Gear but never got to it.
You must be logged in to view this image or video.
If any of you know how Ceddy and Tephra start out finding all the maps and such, they use a method called disassembly, it uses software to turn the meaningless 1's and 0's that we copy from the ECU in to a ROM file into something called assembly language. And if youv'e ever done computer coding with a high level language you will know that reading low level assembly language is 10 times harder than that. It's full on reverse software engineering taking a program a team of other people wrote and trying to figure it out blind just from processor instructions. I say that so you know the amount of effort people like Ceddy and Tephra had to put in to their ROM's and why no further development of the Eclipse black box has been done since Ceddy moved on.
So that's where I come in. I'm not a Ceddy but I do have some experience with high level coding and computers and after using CeddyMods for years I always wanted some type of Boost Control just like the Evo guys have. So a few years ago I sent Ceddy an email and being the great guy he is he sent me his disassembly file with his notes from his original work. It does'nt have the special code he added for the CeddyMods specific stuff but everything that he defined that was there from the factory is there so it gave me somewhere to start.
After many long hours of trial and error and testing I found that our cars have almost identical code to what was used in the Evo 5 & 6 and very similar code to what Mitsu used in the Evo 7 & 8. So if you want to learn in detail how the boost control works on our cars I recommend reading the boost control section of the below guide for the Evo 8 as it is the same for the Eclipse.
STEP BY STEP GUIDE:
1. As you will see in that guide the first thing you have to do is ditch your stock Boost Control Solenoid usually reffered to as the BCS get a GM 3 port BCS part number 214474 and plumb it per the below diagram:
You must be logged in to view this image or video.
The real AC Delco solenoid is currently less than $50 on Amazon
You must be logged in to view this image or video.
2. DO NOT DRIVE THE CAR WITHOUT TUNING (See Wastegate RPM Control Below). The largest difference between the Eclipse and the Evo 8 is that our system was designed around 100% duty cycle of the BCS. Meaning it was at 100% duty cycle almost all the time. They used the BCS on the Eclipse to drop the boost DOWN at spool and cut the torque spike which is why so many of us deleted the OEM BCS. But now you have installed the 3 port which is completely different. The 3 port at 100% duty cycle will not open the wastegate at all:
You must be logged in to view this image or video.
3. In order to get boost control working you will have to use my .XML for EcuFlash to get the correct tables. Go to the below directory on your computer:
C:\Program Files (x86)\OpenECU\EcuFlash\rommetadata\mitsubishi\eclipse
Then replace the 20550011.XML with the 2055011 1998 USDM Eclips GST MT - Boost Control.XML I have attached. (It would not let me upload a .XML so I changed it to a .TXT text file. When you put it in the folder make sure you change the .TXT file extension back to .XML)
You must be logged in to view this image or video.
4. Open ECUFlash and open your CeddyMods ROM. The WasteGate section will now have all the maps I have defined:
You must be logged in to view this image or video.
5. Tune It! We are going to be setting up our tables just like the Evo 8 so if you haven't please go read the Merlin's tuning guide I posted above so you can understand what I'm doing.
Boost Desired Engine Load (BDEL) & Boost Control Offset (BCO):
The BDEL table is the target load that the boost control is trying to hit. Meaning if you spool to 15psi and hit 160 load but this table is set for 200 load the ECU will start adding duty cycle to the solenoid and upping the boost to try and hit the load value. This table max's out at 160 load so to be able to do bigger loads Mitsu used an "adder" value which is the BCO. So the target load is
BDEL Table Lookup + BCO Value = Target Load
Below you can see the original BDEL table with my "tuned" table on the right:
You must be logged in to view this image or video.
Factory BCO is set to 40:
You must be logged in to view this image or video.
You can see they target max load the entire time except during spool and just after spool to keep the torque spike down. So the factory target load is 160 + 40 = 200% which by no coincidence is the same as the factory boost cut. Which shows how the factory BCS was designed to never be able to boost the car harder just drop the boost down some. For me I was targeting 250 Load so I changed my BCO value to 90 and put the BDEL table at a full 160. You can make both BDEL tables 1 and 2 the same but it only uses the first map unless you have map switching set up.
Base Wastegate Duty Cycle:
This table is exactly as the title says. Its the starting duty cycle of the solenoid per RPM. If you leave it set at 100% during spool it can slightly improve your spool time by keeping the wastegate from popping early. You want to set this LOW to start out with and bring it up slowly after making some runs to see what duty cycle correlates to how much boost. I start at 25% duty cycle. Factory map left starting tune map right:
You must be logged in to view this image or video.
Again set both 1&2 maps to the same values.
Turbo Boost Error Correction
This map works off of the error calculated from the BDEL table above. Meaning you start out in the pull and it takes Target Load - Actual Load = Error. Then depending on that error + or - out of this table it selects a value to add to the duty cycle.
You must be logged in to view this image or video.
So if my target load is 250% and at 25% base duty cycle I am hitting 230% load it will be 250 - 230 = 20% error and it will add 7.5% every cycle to the solenoid duty cycle.
Max Total Upward Correction
Exactly as it says this limits the amount of upward error correction that can be added on. So from our example say we are at 25% duty cycle and not hitting 250 load. The error correction will add 7.5% duty cycle the first time and now we are at 32.5% duty cycle. If the load is still not at 250 the error correction can only add 2.5% more duty cycle for a total of 35% duty cycle at full throttle according to this map:
You must be logged in to view this image or video.
This keeps you from over boosting if there is a boost leak or some other issue that causes you load to be high.
WasteGate Airflow Control
This map is not found in the Evo 8 and is unique to the Eclipse. This is the airflow limit for boost control. If the MAF Hz goes above the top value, the ECU will drop the wastegate duty cycle to 0 as a protective measure. It will not reengage boost control until the Hz level falls below the bottom number
You must be logged in to view this image or video.
WasteGate Octane Control
This map is also unique to the Eclipse and not found on the Evo. It is the Octane level limit for boost control. If the Octane Level falls below the top value, the ECU will drop the wastegate duty cycle to 0 as a protective measure. It will not reengage boost control until the Octane level rises above the bottom number.
You must be logged in to view this image or video.
WasteGate RPM Control
This map can be found in the Evo but it works slightly differently in our cars. The Evo was setup for actual boost control from the factory so outside of the control range it defaults to 0% duty cycle. For us since the BCS was designed around max duty cycle outside of the control range the wastegate duty cycle defaults to 100% duty cycle. So for the bottom 2 numbers "Deactivate Rising" and "Deactivate Falling" you want to set those to 8000 or whatever your rev limit is to make sure boost control does not shut off and go to 100% duty mid pull. Let me reiterate that - IF YOU DO NOT CHANGE THIS THE WASTEGATE WILL NOT OPEN ABOVE 3812 RPM - Sorry for the all caps but don't want anyone blowing their engine up at max boost.
You must be logged in to view this image or video.
Alright so that's it. Go out and make some pulls and get your Base Duty Cycle and Desired Load setup and enjoy factory Mitsubishi boost control.
I did not do any custom coding for this all of these maps are there from the factory. So this .XML will work with any 2055 ROM including the BigMaps and SD ROMS. Huge thanks to Ceddy for sending me his disassembly without that this would not have been possible and he did not have todo that. Awesome guy.
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