how-to: ECU-based direct boost control
mrfred, just in case you hadn't seen it, Tom and Dave (of ECMLink fame) have a page up on their selection criteria for a good BCS for ECMLink and the 1g/2g DSM ECUs (they just recently added support for BCS control to ECMLink): http://www.ecmtuning.com/wiki/bcschoice
The interesting tidbit is the one about blowing the internal driver in the HC11/H8 ECUs with a GM BCS.
The interesting tidbit is the one about blowing the internal driver in the HC11/H8 ECUs with a GM BCS.
Thread Starter
EvoM Guru
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Interesting tidbit on BCS recommendations. Its not clear to me that they've seen a GM BCS blow the driver on the DSM ECUs. The blown driver page covers the ISC system and not the BCS.
Which isn't too surprising; they just released the feature, so it's not exactly "in the wild" much right now, and I suspect they weren't in a hurry to force the driver to blow on the bench. 
(I know they see blown ISC drivers pretty regularly, though, as does a friend of mine who does a fair bit of ECU repair work.)
Ceddy, if you're reading this: do you know if any folks with the H8 ECUs have been having issues here?
(I know they see blown ISC drivers pretty regularly, though, as does a friend of mine who does a fair bit of ECU repair work.)Ceddy, if you're reading this: do you know if any folks with the H8 ECUs have been having issues here?
Evolving Member
Joined: Nov 2008
Posts: 424
Likes: 3
From: Russia, Moscow
Hi guys!
I am trying to use Defi map sensor for direct boost control. I've already figured out evoscan formula and logging boost succsesfully, but still can't understand ecuflash expressions..
Can anybody help to work out ecuflash expression for this particular sensor, or just explain the expressions for map sensor in ecuflash, so that i could do that math myself.
Thanks.
PS 1,86v@1bar (0bar boost) 4,49v @3bar (2bar boost)
I am trying to use Defi map sensor for direct boost control. I've already figured out evoscan formula and logging boost succsesfully, but still can't understand ecuflash expressions..
Can anybody help to work out ecuflash expression for this particular sensor, or just explain the expressions for map sensor in ecuflash, so that i could do that math myself.
Thanks.
PS 1,86v@1bar (0bar boost) 4,49v @3bar (2bar boost)
Last edited by Biggy VIII; Sep 10, 2010 at 01:13 AM.
Evolving Member
Joined: Nov 2008
Posts: 424
Likes: 3
From: Russia, Moscow
If anyone interested in using Defi BF MAP sensor for direct boost control and SD, I have worked out these expressions. I did some testing using direct boost control and SD and everything seems to work fine.
It would be cool if anybody could check my math and test theese scalings too.
Until it haven't been tested properly by several people use this at your oun risk.
for evoscan:
PS I am using ecuflash 1.29, so dont forget to change endian for newer versions.
It would be cool if anybody could check my math and test theese scalings too.
Until it haven't been tested properly by several people use this at your oun risk.
Code:
<scaling name="BoostErrorBar DefiMAP" units="Bar" toexpr="((x-128)*0.02725)/14.5" frexpr="(x*14.5)/0.02725+128" format="%.2f" min="-0.8" max="0.8" inc="0.01" storagetype="uint16" endian="little"/> <scaling name="BarA16 DefiMAP" units="Bar" toexpr="(x*0.108-3.06)/14.5" frexpr="(x*14.5+3.06)/0.108" format="%.2f" min="0" max="3.1" inc="0.01" storagetype="uint16" endian="little"/> <scaling name="BarA8 DefiMAP" units="Bar" toexpr="(x*0.108-3.06)/14.5" frexpr="(x*14.5+3.06)/0.108" format="%.2f" min="0" max="3.1" inc="0.01" storagetype="uint8" endian="little"/> <scaling name="kPa DefiMAP" units="kPa" toexpr="x*0.371680-41.4587" frexpr="(x+41.4587)/0.371680" format="%.1f" min="0" max="320" inc="1" storagetype="uint16" endian="little"/>
Code:
<DataListItem DataLog="N" Color="" Display="Boost(Defi)" LogReference="DefiBoost" RequestID="38" Eval="0.216208*x-20.511667" Unit="PSI" MetricEval="(0.216208*x-20.511667)/14.5" MetricUnit="Bar" ResponseBytes="1" GaugeMin="-1" GaugeMax="2" ChartMin="-1" ChartMax="2" ScalingFactor="1" Notes="" Priority="1" Visible="False" />
<DataListItem DataLog="N" Color="" Display="Map(Defi)" LogReference="DefiMAP" RequestID="38" Eval="0.216208*x-6.011667" Unit="PSI" MetricEval="(0.216208*x-6.011667)/14.5" MetricUnit="Bar" ResponseBytes="1" GaugeMin="0" GaugeMax="3" ChartMin="0" ChartMax="3" ScalingFactor="1" Notes="" Priority="1" Visible="False" />
Last edited by Biggy VIII; Sep 25, 2010 at 03:07 AM. Reason: SD tested on my car.
Hello,
How to set psi adder and boost desired psi table ? I dialed in my boost in every gear ( 3th, 4th and 5th, have to play a lot to avoid overs boost in 4th and 5th ) with zero boost error psi correction table. I had 26psi to 24psi redline.
Than set the error correction table as in the 1st post, the psi adder to 18.7 and my boost desired egnie psi table 22psi to 20psi the result is my boost go a way had only 17psi lot of error correction wgdcc and low wgdc.
Than just playing with the boost desired engine psi table to set it 29psi to 28 psi redline and get back my boost what was without the error correction. 0.5 psi boost error. Than question is why my boost desired engine psi is so high 29 psi with 18.7 psi adder ?! How to set these tables? thank you !
How to set psi adder and boost desired psi table ? I dialed in my boost in every gear ( 3th, 4th and 5th, have to play a lot to avoid overs boost in 4th and 5th ) with zero boost error psi correction table. I had 26psi to 24psi redline.
Than set the error correction table as in the 1st post, the psi adder to 18.7 and my boost desired egnie psi table 22psi to 20psi the result is my boost go a way had only 17psi lot of error correction wgdcc and low wgdc.
Than just playing with the boost desired engine psi table to set it 29psi to 28 psi redline and get back my boost what was without the error correction. 0.5 psi boost error. Than question is why my boost desired engine psi is so high 29 psi with 18.7 psi adder ?! How to set these tables? thank you !
and than I can write in the boost desired engine psi table 26psi @ peak and 24psi at redline ? My boost error was lower If i dial in higher psi numbers in the table with 18.7 psi adder.
Evolving Member
Joined: Dec 2005
Posts: 232
Likes: 0
From: South Africa
Hi all,
In evoscan map tracer I noticed the boost logging only logs to 1 decimal place (I am using BAR, not psi) so my resolution is not that good, as I can only see 1.45psi increments.
It would be good to see to 2 decimal places as I can then see if I am at 1.9 or 1.99bar
It logs to 5 decimal places on the evoscan screen, but not on the map tracer.
is there a way we can log to 2 decimal places?
Mike
In evoscan map tracer I noticed the boost logging only logs to 1 decimal place (I am using BAR, not psi) so my resolution is not that good, as I can only see 1.45psi increments.
It would be good to see to 2 decimal places as I can then see if I am at 1.9 or 1.99bar
It logs to 5 decimal places on the evoscan screen, but not on the map tracer.
is there a way we can log to 2 decimal places?
Mike
Please someone tell me what did I wrong I read and understand how the system work it seems like so simple.
I would flat 26psi boost curve until ~5500-6000rpm than tappering to 23.5psi 7000rpm.
My setup : Stock Evo9 turbo on the Evo8 engine , GM3port boost control solenoid, the rom is the psi based 9653 opt 4. v7 with Omni 4 bar map sensor.
I coud set my boost curve in 3th gear with error correction psi table zero out.
I have 26psi from 3500to 6000rpm than tappering to 23.5psi.
The problem with erroc correction table and the Boost adder psi + Boost desired engine psi tables. I'm on sea level, and would like 26psi boost.
So I set my Boost adder psi table to 19.7psi. the boost desired engine psi table from 500rpm until 6000 set to 21psi. Is that mean my target boost is 26psi ??
Beacuse with that setting the ecu pull down my boost to 16psi @4000rpm. Than adjust back 18.5psi @4750 where the boost error was 0 !!
log picture 1
Seems like I'm off with 7.5psi. Than I add these value to my Boost adder psi table and runing with 27.2 psi in the adder and 21 psi in tbe boost desired engie psi table. The boost was better but not as flat as without the error correction ! boost error was between -0.8 - 0.2 psi . But Why I have to adjust the psi adder to 27.2 ?
log picture 2
With the 3th gear wastegate duty cyle setting and error correction I always have lot of over boost in 4th gear than the ecu pull down the boost and than again try to adjust back.
Please tell me Where is the problem ?
I read and understand how the system work it seems like so simple. I would flat 26psi boost curve until ~5500-6000rpm than tappering to 23.5psi 7000rpm.
My setup : Stock Evo9 turbo on the Evo8 engine , GM3port boost control solenoid, the rom is the psi based 9653 opt 4. v7 with Omni 4 bar map sensor.
I coud set my boost curve in 3th gear with error correction psi table zero out.
I have 26psi from 3500to 6000rpm than tappering to 23.5psi.
The problem with erroc correction table and the Boost adder psi + Boost desired engine psi tables. I'm on sea level, and would like 26psi boost.
So I set my Boost adder psi table to 19.7psi. the boost desired engine psi table from 500rpm until 6000 set to 21psi. Is that mean my target boost is 26psi ??
Beacuse with that setting the ecu pull down my boost to 16psi @4000rpm. Than adjust back 18.5psi @4750 where the boost error was 0 !!
log picture 1
Seems like I'm off with 7.5psi. Than I add these value to my Boost adder psi table and runing with 27.2 psi in the adder and 21 psi in tbe boost desired engie psi table. The boost was better but not as flat as without the error correction ! boost error was between -0.8 - 0.2 psi . But Why I have to adjust the psi adder to 27.2 ?
log picture 2
With the 3th gear wastegate duty cyle setting and error correction I always have lot of over boost in 4th gear than the ecu pull down the boost and than again try to adjust back.
Please tell me Where is the problem ?
Your desired boost table should be set at 24.6 psi. Depending on your elevation, your boost adder should be atmospheric pressure + 1.4 psi (since you want 26 psi total or 26-24.6=1.4)
The key is the 24.6 in the desired boost table ?
For the Ecu my settings the 19.7 in the boost adder psi ( 14.7+5 ) and in the desired table 21psi is different ?! ( total boost should be 21+5=26psi too or not ?
( with that setting i can hit 25.8psi for a moment @3500rpm where the boost error was +3.1 psi !! so the ecu apply -11 than 19% wgdc correction than -15% to get the boost error close to 0 ( -0.0022psi ) . At the point when the boost error was 0 the I logged 18.5psi ?! I really dont understand why ?
Is that mean my 19.7 boost adder and 21psi desired boost is mean for my Ecu only 18.5psi ?
Why are the max value what I can set in the desired engine psi table is 37.5 and not 24.6 psi ? ( just for take look than in my boost desired engine load table are the value is 159.4 ) . The minimum value what i can write in the desired engine psi table is 7.4 psi .
When I set 100 in the boost adder load table than I see 18.9 in the boost adder psi If it is help.
Scalings :
MrFred is posted in the 1st post that for the Omni 4bar :
<scaling name="psia8" units="psia" toexpr="x/(4.23*2)" frexpr="x*(2*4.23)" format="%.1f" min="0" max="30.1" inc="0.1" storagetype="uint8" endian="big"/>
For me in the V7 :
PSIa8 OMNI4barMAP-Adj" units="PSIa" toexpr="(x/(4.23*2))+7.4" frexpr="(x-7.4)*(2*4.23)" format="%.1f" min="0" max="30.1" inc="0.1" storagetype="uint8" endian="big"/>
What is that +7.4 ?
If add this to the 18.5psi logged value where the error correcton was zero I will get 25.9psi what should be my desired... What is the trick in the V7 ?
Nobody has problem with that before me ?
PSIa18 omni 4barmap-adj scaling is what my boost desired engine psi are have.
The other scaling ( psia16, wgdc offset, boost error psi ) is the same.
Last edited by VGergo; Oct 2, 2010 at 01:57 AM.
I cant for the life of me remember why the +7.4 would be added in the V7 versions though.