psi based boost control
I am using this direct boost control. Had the car performing poorly after going to a higher height place in a time attack event. Had to reflash over there. Some months ago I had given up using a stand-alone 3-port EBC, replacing it by a GrimmSpeed 3-port solenoid, and letting the ECU controls the boost. But since I am currently using direct boost control, what would be the advantage of the ECU boost controlling? My old standalone EBC (HKS EVC-S) respond to overboost instantly. The curve is way smoother and spoolup 500rpm faster. I know I am not able to build a custom-shaped boost curve as with the ECU+3-port solenoid, but most of the times, the MBC like curve is what we want.
Besides all of this, it looks there is some logical flaw with the boost tuning method we use. We zero out BEC and set the WG numbers. Ok. Then we adjust BTEL table (or Boost Target) to align it to the load/boost we get. Then we restore the BEC. By doing this, whenever we get some incline, we overboost, unless we keep the top BEC positive numbers zero. It just dont seems correct.
I might resinstall my HKS EVC-S and try to check how it works... I mean, how frequently it adjusts WGDC in different conditions:
- Normal pull from 2000-7000;
- Suddenly applying the gas pedal at around 4000-5000;
- Up and downhills;
Maybe I might learn the best combination of WGDC.
I ve read somewhere these standalone EBC use fuzzy logic in order to control boost. This looks more promising than the simplistic aritmetrical rules the Evo X ECU uses to control boost.
Does anyone knows exactly which safety measures the stock ECU has for controlling boost, which are not present in standalone EBC.
Just to make things clear:
- Standalone EBC: Devices eletronically controlling the boost, without the help of the ECU (these can even use 3-port solenoid, but have their own ecu, such as HKS EVC);
- MBC: Devices controlling the boost by mechanical ways, adjusted manually;
- 3-Port Solenoid: A device, controlled by the stock ECU, for adjusting boost (such as the GrimmSpeed 3-port);
My HKS EBC-S has a 3-port solenoid besides its own "computer" for controlling boost. I could never have a smoother curve with the 3-port GS. There are always some hills and peaks specially around 3500-5000, even after using smaller (3) correction intervals and small BEC values.
Besides all of this, it looks there is some logical flaw with the boost tuning method we use. We zero out BEC and set the WG numbers. Ok. Then we adjust BTEL table (or Boost Target) to align it to the load/boost we get. Then we restore the BEC. By doing this, whenever we get some incline, we overboost, unless we keep the top BEC positive numbers zero. It just dont seems correct.
I might resinstall my HKS EVC-S and try to check how it works... I mean, how frequently it adjusts WGDC in different conditions:
- Normal pull from 2000-7000;
- Suddenly applying the gas pedal at around 4000-5000;
- Up and downhills;
Maybe I might learn the best combination of WGDC.
I ve read somewhere these standalone EBC use fuzzy logic in order to control boost. This looks more promising than the simplistic aritmetrical rules the Evo X ECU uses to control boost.
Does anyone knows exactly which safety measures the stock ECU has for controlling boost, which are not present in standalone EBC.
Just to make things clear:
- Standalone EBC: Devices eletronically controlling the boost, without the help of the ECU (these can even use 3-port solenoid, but have their own ecu, such as HKS EVC);
- MBC: Devices controlling the boost by mechanical ways, adjusted manually;
- 3-Port Solenoid: A device, controlled by the stock ECU, for adjusting boost (such as the GrimmSpeed 3-port);
My HKS EBC-S has a 3-port solenoid besides its own "computer" for controlling boost. I could never have a smoother curve with the 3-port GS. There are always some hills and peaks specially around 3500-5000, even after using smaller (3) correction intervals and small BEC values.
The benefit is that you can have the ECU controlling all portions of the valve. In the CT9A you can do temperature corrected controls, and I believe one of the boost maps is baro related so you can use that for help with elevation. You don't necessarily want 20psi at 50% throttle... otherwise you are heating up your turbo more than necessary... that is where the 3d throttle table comes in handy.
Really, in the end it comes down to personal preference.
Tephra, if you want to add to the first post:
52360018:
I believe this is correct. I may have copied and pasted wrong... I tried to make the format exactly the same as your first post.
52360018:
Code:
<scaling name="Throttle_Main - Stored Minimum Throttle %" units="%" toexpr="(x+(90/4))*100/255" frexpr="x*255/100-(90/4)" format="%.1f" min="0" max="100" inc="2" storagetype="uint16" endian="big"/>
<scaling name="BoostErrorPsi" units="psi" toexpr="(x-128)*0.19347/4" frexpr="(x*4/0.19347)+128" format="%.1f" min="-6.1" max="6.1" inc="0.1" storagetype="uint16" endian="big"/>
<scaling name="OffsetWGDC" units="WGDC Change" toexpr="(x-128)/2" frexpr="x*2+128" format="%.1f" min="-64" max="63.5" inc="0.5" storagetype="uint8" endian="big"/>
<scaling name="psia8" units="psia" toexpr="x*0.19347" frexpr="x/0.19347" format="%.1f" min="0" max="49.5" inc="0.1" storagetype="uint8" endian="big"/>
<scaling name="psia16" units="psia" toexpr="x*0.19347" frexpr="x/0.19347" format="%.1f" min="0" max="49.5" inc="0.1" storagetype="uint16" endian="big"/>
<table name="Atmospheric Boost" category="Direct Boost" address="53484" type="1D" scaling="psia16"/>
<table name="Target Boost Error Correction" category="Direct Boost" address="58cd8" type="2D" scaling="OffsetWGDC">
<table name="Boost Error" address="625be" type="Y Axis" elements="17" scaling="BoostErrorPsi"/>
</table>
<table name="Boost Target #1A (High Gear Range)" category="Direct Boost" address="58e45" type="3D" swapxy="true" scaling="psia8">
<table name="Throttle" type="X Axis" elements="9" scaling="Throttle_Main - Stored Minimum Throttle %" address="62616"/>
<table name="RPM" type="Y Axis" elements="18" scaling="RPM" address="62594"/>
</table>
<table name="Boost Target #1B (High Gear Range)" category="Direct Boost" address="58eef" type="3D" swapxy="true" scaling="psia8">
<table name="Throttle" type="X Axis" elements="9" scaling="Throttle_Main - Stored Minimum Throttle %" address="62616"/>
<table name="RPM" type="Y Axis" elements="18" scaling="RPM" address="62594"/>
</table>
<table name="Boost Target #2 (Low Gear Range)" category="Direct Boost" address="573f5" type="3D" swapxy="true" scaling="psia8">
<table name="Throttle" type="X Axis" elements="9" scaling="Throttle_Main - Stored Minimum Throttle %" address="62616"/>
<table name="RPM" type="Y Axis" elements="18" scaling="RPM" address="62594"/>
</table>
<table name="Variable for Boost Control 0xC76C -> 0xC712" category="Direct Boost" address="9e92a" type="1D" scaling="Hex16"/>
<table name="SHLR->SHLR2 0x5101 -> 0x5102" category="Direct Boost" address="9e92c" type="1D" scaling="Hex16"/>
<table name="Boost Error RAM Address 0xC588 -> 0xC586 (is 0x808586 for logging)" category="Direct Boost" address="9e952" type="1D" scaling="Hex16"/>
<table name="Boost Error RAM Address in Load Error Table 0xC588 -> 0xC586" category="Direct Boost" address="625ba" type="1D" scaling="Hex16"/>
I believe this is correct. I may have copied and pasted wrong... I tried to make the format exactly the same as your first post.
Last edited by Golden; Mar 3, 2011 at 06:58 AM. Reason: 1 address was slightly off.
Boost Limit Table.... psi or load units?
Quick question I did not see covered already...
When moving to direct (PSI) boost control... is the boost limit table still in load units or should the scaling be updated for that table to reflect psi instead????
When moving to direct (PSI) boost control... is the boost limit table still in load units or should the scaling be updated for that table to reflect psi instead????
Are the EvoScan addresses the same in this rom or different from 0007? Wish EvoScan was kept updated with all the addresses cause thats the biggest pain for me so far coming from an AEM background.
Also I think I remember seeing a 56890010 rom is this newer than 0009? I am guessing so, so are your definitions updated for that one also or is 0009 the money maker for defined tables?
I know this is a bit out of scope on this thread but for example upgrading is as simple as just flashing the stock 0009 rom over my stock 0007 rom. If I had changed any specific tables just copy them over, which at this time is only Mode23 while I get a feel for everything. I am guessing the 0009 is a factory upgrade so its that simple?
Also I think I remember seeing a 56890010 rom is this newer than 0009? I am guessing so, so are your definitions updated for that one also or is 0009 the money maker for defined tables?
I know this is a bit out of scope on this thread but for example upgrading is as simple as just flashing the stock 0009 rom over my stock 0007 rom. If I had changed any specific tables just copy them over, which at this time is only Mode23 while I get a feel for everything. I am guessing the 0009 is a factory upgrade so its that simple?
Yes the evoscan addresses are different. Email me if you want them.
0010 is identical definition wise to 0009. Both defs are up on my site. You will need both for the 0010 rom.
Yes. Copy, paste, flash. Done. Or in your case, turn on mode 23 and flash.
edit: If you need a rom, I can email you one, or check Bryan's rom site.
0010 is identical definition wise to 0009. Both defs are up on my site. You will need both for the 0010 rom.
Yes. Copy, paste, flash. Done. Or in your case, turn on mode 23 and flash.
edit: If you need a rom, I can email you one, or check Bryan's rom site.
Golden you were not kidding there are a ton more tables defined, thanks for the suggestion and tip!
So question is does anyone have the information for PSI base boost control for 56890009 and more specifically 56890010 which i think would match 0009 anyway? (I flashed 56890010 to my car last night).
So question is does anyone have the information for PSI base boost control for 56890009 and more specifically 56890010 which i think would match 0009 anyway? (I flashed 56890010 to my car last night).
