how-to: ECU-based direct boost control
Nov 17, 2008 | 07:46 PM
#541
i think i found the issue the left side of the BEC and TBEC aren't matched up...i know the tbec is -20 to 20 and the bec is -3 to 3..but thats not what i'm seeing...and i checked the xml and its exactly whats listed so i'm not sure whats being mis calculated.
Nov 18, 2008 | 01:10 PM
#543
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Ok, so I spent a few hours this weekend on a new rom w/ "direct boost control" dialing in 3rd gear (to start). and have come up w/ a couple more qustions...
1. I noticed on other peoples maps that have been posted, the WGDC is substanstially lower than w/ the stock BCS... But both the roms I have been working on (load/psi based) have had much higher WGDC. Well I decided I was gonna start from scratch and work my way up to desired boost levels... I basically set up the WGDC @ 100% @ 1000-2500, 75% @ 2750 and straight 50% till 6000, I left the rest of the map alone. Well this net me 14psi until 6000... So I started working my way up... Ended up w/ 100% till 2500, 85% @ 2750, and 80% till 4500, then tapering a bit. Im hitting desired boost perfectly. w/in -.5 to -.009, but hitting boost way late!!! 3750 +...
so my first question is why do I need to run soo much WGDC to achieve the similar boost levels that most are seeing w/ lower WGDC?
2. So I have my psi based rom set up for (3rd) on point, and Im hitting full boost @ 3750 +??? WTF??? w/ my load based rom, Im hitting same boost level @ 3406...
On another note this patch makes tuning boost much easier, I just wish I could figure out why Im hitting full boost so late...
1. I noticed on other peoples maps that have been posted, the WGDC is substanstially lower than w/ the stock BCS... But both the roms I have been working on (load/psi based) have had much higher WGDC. Well I decided I was gonna start from scratch and work my way up to desired boost levels... I basically set up the WGDC @ 100% @ 1000-2500, 75% @ 2750 and straight 50% till 6000, I left the rest of the map alone. Well this net me 14psi until 6000... So I started working my way up... Ended up w/ 100% till 2500, 85% @ 2750, and 80% till 4500, then tapering a bit. Im hitting desired boost perfectly. w/in -.5 to -.009, but hitting boost way late!!! 3750 +...
so my first question is why do I need to run soo much WGDC to achieve the similar boost levels that most are seeing w/ lower WGDC?
2. So I have my psi based rom set up for (3rd) on point, and Im hitting full boost @ 3750 +??? WTF??? w/ my load based rom, Im hitting same boost level @ 3406...
On another note this patch makes tuning boost much easier, I just wish I could figure out why Im hitting full boost so late...
2. There's no reason why boost should be hitting so late compared to load-based boost control. Something is not right.
Post your BEC table.
Nov 18, 2008 | 02:37 PM
#544
2. So I have my psi based rom set up for (3rd) on point, and Im hitting full boost @ 3750 +??? WTF??? w/ my load based rom, Im hitting same boost level @ 3406...
On another note this patch makes tuning boost much easier, I just wish I could figure out why Im hitting full boost so late...
On another note this patch makes tuning boost much easier, I just wish I could figure out why Im hitting full boost so late...
Nov 18, 2008 | 02:42 PM
#545
[QUOTE=mrfred;6364560]1. Its possible that your WGA needs adjusting.
2. There's no reason why boost should be hitting so late compared to load-based boost control. Something is not right.
Can I send you my rom to look at? I believe all necessary changes were made, but, maybe... I missed somethin.
Theres really only 2 differences in my 2 roms (load/psi) Load I have WGDC set to a flat 77% till peak @ 80%, then tapering upward.
w/ PSI I had WGDC @ 100% till 2500 tapering down to 80% @ peak, thinking this would help spool up... looks like I thought wrong. lol
I would post up the logs, but Im having issues w/ zip files...
2. There's no reason why boost should be hitting so late compared to load-based boost control. Something is not right.
Can I send you my rom to look at? I believe all necessary changes were made, but, maybe... I missed somethin.
Theres really only 2 differences in my 2 roms (load/psi) Load I have WGDC set to a flat 77% till peak @ 80%, then tapering upward.
w/ PSI I had WGDC @ 100% till 2500 tapering down to 80% @ peak, thinking this would help spool up... looks like I thought wrong. lol
I would post up the logs, but Im having issues w/ zip files...
Nov 19, 2008 | 08:13 PM
#546
Dec 1, 2008 | 09:42 AM
#547
The other thing that would make things easier is the ability to introduce a step change in the boost target. Map switching could do this, but you'd have to be on a dyno.
Dec 1, 2008 | 04:14 PM
#549
Dec 1, 2008 | 04:28 PM
#551
what if we had a table that had TPS, RPM and % where % is the percentage of the WGDC value in the gear table. For instance if at 50% throttle i only wanted 50% of the WGDC value at that RPM in gear table. I personally think we would only need 4 colums for TPS, RPM range then %. I hope i am not asking for the world I just think ramp rate still needs to be address. I am very appreciative of the gear dependent boost, dont get me wrong.
Dec 1, 2008 | 04:44 PM
#553
Oh yeah i understand that. I guess the point would just to really make part throttle spool more subtle. i am willing to deal with part throttle for the gear dependent boost so whatever can be done i am willing to accept - like i have a choice :P. I appreciate you at least entertaining the idea.
Dec 1, 2008 | 07:22 PM
#554
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From: ft. walton beach, FLORIDA
Has anyone had any problems with boost spiking at high rpms? I have my boost curve really good right now, but at 8000 rpms my boost just goes up past 35 psi. My target boost is 26 psi. Any ideas? I rescaled my rpm axis to 9000
