how-to: ECU-based direct boost control - Page 61

cmj · Oct 29, 2009, 10:43 AM

I just got around to implementing ecu boost control into the new V7 maps, but something is not right. I currently have NO positive correction set up in the Boost Error Correction table, only a little negative correction for over boost. My current wastegate duty cycle gives me about 1psi over my desired boost of 28.8. Boost adder is set to 18.7 and base boost is set to 24.6, so downward correction should be needed. When I log with evoscan boost error reads -3.087 then jumps to 3.056 at about 27psi. Also whenever I go WOT the WGDCC jumps to 5 which happens to be the max upward correction vs. tps.

Any idea why max upward correction vs. tps would be maxing out when there is no positive correction set up?

fostytou · Oct 29, 2009, 12:39 PM

Quote:

Originally Posted by Raceghost

This I understand. I am utilizing the ECU, 3port solenoid, and 4 bar map sensor for PSI/ECU based control.

Below are my 22 lbs. boost tables. I am back on my lower settings due to the crappy Utotion gas. I really am confused about the naming of the tables. As I learn to tune myself here, and listening to you guys, I am hungup on the high gear and low gear settings. Low gear would make sence of the 1st thru 3rd gear, but it is actually the 4th and 5th gear settings. It seems the tables are reversed unless I am misunderstanding something?

Should I swap them? Should I make them equal?

Sounds like a rediculous question I know, but I would think you would want higher boost the faster the RPM. Can you straighten me out?

It might be better to call it "low gear ratio".

To answer your last question, you can have more boost in the higher gears because there is more load on the engine. In reality on a smaller turbo I think it simply shifts the whole curve left, but that may not translate perfectly to the real world.

fostytou · Oct 29, 2009, 12:44 PM

Quote:

Originally Posted by cmj

I just got around to implementing ecu boost control into the new V7 maps, but something is not right. I currently have NO positive correction set up in the Boost Error Correction table, only a little negative correction for over boost. My current wastegate duty cycle gives me about 1psi over my desired boost of 28.8. Boost adder is set to 18.7 and base boost is set to 24.6, so downward correction should be needed. When I log with evoscan boost error reads -3.087 then jumps to 3.056 at about 27psi. Also whenever I go WOT the WGDCC jumps to 5 which happens to be the max upward correction vs. tps.

Any idea why max upward correction vs. tps would be maxing out when there is no positive correction set up?

Double check your mods.

tephra · Oct 29, 2009, 06:50 PM

cmj - post up pictures of your map setup

lan_evo_mr9 · Oct 29, 2009, 10:33 PM

will there be an "alt map direct boost control table(s)" and a main direct boost control tables for 8859xx15? Or has been implemented and my dumb ass has missed something?

fostytou · Oct 30, 2009, 09:37 AM

Quote:

Originally Posted by lan_evo_mr9

will there be an "alt map direct boost control table(s)" and a main direct boost control tables for 8859xx15? Or has been implemented and my dumb ass has missed something?

No, you probably didn't miss the 50 or so posts about how to do it.... it just sailed about 10,000 ft over you head

I'll say it again for you. If you have a tephra rom, implement the patch and change the scaling. The patch works with tephra roms, and the tephra roms already have alternate boost maps. Once you change the scaling you will 'see' the changes that have already taken place.

lan_evo_mr9 · Oct 30, 2009, 02:11 PM

^I wasn't referring to load based.

How do I implement an "alternate Boost Desired Engine PSI", just like the modded 96530706 v rom? I want to have two gear based "Alternate Boost Desired Engine PSI" just like the evo 8 rom. ie, one for pump and one for E85. When I implement the direct boost patch, I only get one table for the main map, not alt map.

Edit: I just copied the definition from another v7 xml, pasted it into my v7 xml, figured out the correct addresses, and there you go- Alt direct boost maps and main direct boost maps.

Here ya go:
<table name="Alternate Boost Desired Engine 'PSI'" category="TephraMod-V7" address="4a1cd" type="3D" level="1" swapxy="true" scaling="psia8">
<table name="Gear" address="511c2" type="X Axis" elements="7" scaling="uint16"/>
<table name="RPM" address="722e" type="Y Axis" elements="16" scaling="RPM"/>
</table>

Raceghost · Oct 30, 2009, 09:56 PM

Quote:

It might be better to call it "low gear ratio".

To answer your last question, you can have more boost in the higher gears because there is more load on the engine. In reality on a smaller turbo I think it simply shifts the whole curve left, but that may not translate perfectly to the real world.

Fosty,

Thanks for the reply. To understand, the higher the gear, the lower the ratio...? So boost should utilize "Low Gear Ratio", (or table 4) when in 4th and 5th?

Daily driven, any suggestions on these settings in reference to that would be great.

Thanks again.

mchuang · Oct 30, 2009, 11:16 PM

What scaling do you guys use for omni 4 bar. the psia8 or psia16?

shadow1 · Oct 31, 2009, 06:06 AM

Quote:

Originally Posted by mchuang

What scaling do you guys use for omni 4 bar. the psia8 or psia16?

mrfred posted this in the first post of this thread.

mchuang · Oct 31, 2009, 08:38 AM

Quote:

Originally Posted by shadow1

mrfred posted this in the first post of this thread.

I am aware of that those are just scalings, im trying to figure out which to use for 2 maps that use as a scaling for boost adder and boost desired engine psi maps, as currently for boost adder i am using psia16 omni 4bar setting and for boost desired engine i am using psia8 omni 4bar and i want to make sure that is correct.

mrfred · Oct 31, 2009, 09:46 AM

Quote:

Originally Posted by mchuang

I am aware of that those are just scalings, im trying to figure out which to use for 2 maps that use as a scaling for boost adder and boost desired engine psi maps, as currently for boost adder i am using psia16 omni 4bar setting and for boost desired engine i am using psia8 omni 4bar and i want to make sure that is correct.

There should be a link to OMNI 4-bar scalings in the first post of this thread.

cmj · Nov 4, 2009, 06:08 PM

I was having problems getting this to work with the v7 map, so I reinstalled everything and started fresh with the prepatched Recompile_v7 map. Now I have a new issue. Error correction is working but it will not correct downward once it has hit the base duty cycle.

Example: boost is set to 28 wgdc is set to 60%, boost hits 27 and wgdcc adds 8% boost hits 29, new wgdc is 68%. At this point wgdcc kicks in to lower boost but it is only capable of removing what was added, once 8% has been removed downward correction stops even if it is still above the target boost.

Also: "Total max upward duty cycle vs tps" is set to zero accross the board, and "total max downward correction" is set to -50

fostytou · Nov 6, 2009, 11:40 AM

Quote:

Originally Posted by cmj

I was having problems getting this to work with the v7 map, so I reinstalled everything and started fresh with the prepatched Recompile_v7 map. Now I have a new issue. Error correction is working but it will not correct downward once it has hit the base duty cycle.

Example: boost is set to 28 wgdc is set to 60%, boost hits 27 and wgdcc adds 8% boost hits 29, new wgdc is 68%. At this point wgdcc kicks in to lower boost but it is only capable of removing what was added, once 8% has been removed downward correction stops even if it is still above the target boost.

Also: "Total max upward duty cycle vs tps" is set to zero accross the bord, and "total max downward correction" is set to -50

Are you sure your boost adder is correct for your altitude?

cmj · Nov 6, 2009, 02:34 PM

I don't think it’s a boost adder problem. The boost error is working, it adds duty cycle if boost is under the target and pulls duty if it is over the target. Unfortunately it is only able to pull down the positive correction that has been added to the base duty cycle. At this point it is not able to go below base duty cycle.

I don't have a Boost Adder table but i assume it is the same as "Boost Control PSI Offset". I'm at sea leve, psi offset is set to 18.7, "Boost desired engine psi" is maxed out at 24.6. This gives me a target of about 28.6 psi.