how-to: ECU-based direct boost control
Sep 27, 2007, 10:33 PM
#114
my boost error is wrong. ill have 22.0psi @ 3500 in my map. the car hits 24.xpsi @ 3500 and the boost error only says its +.998 off target boost. this happens in various areas. also it seems like the ecu is following the incorrect boost error readings. any ideas?
Last edited by Evo_Jay; Sep 27, 2007 at 10:36 PM.
Sep 28, 2007, 04:29 AM
#115
First, are you sure EvoScan is logging accurately? Turn the key on but leave the engine off, start logging. JDMMAP should show very close to 0, as in 0.0xxx
If not, fix your EvoScan XML (refer to the JDM MAP instruction thread)
Secondly, is your Boost Adder set to the same value as your EvoScan XML ? For example, if you have to use 14.7 in EvoScan to log 0.0xx boost with engine off, then your Boost Adder should also be 14.7.
Sep 28, 2007, 09:03 PM
#116
I've been getting quite a few questions on how to tune the direct boost control system so in the third post in this thread, I've added a detailed description of how to the direct boost control system works and how to effectively tune it. Hopefully, that will answer most people's questions.
Sep 30, 2007, 08:19 AM
#117
Can anyone translate these formulas into language that Logworks can understand?
<DataListItem DataLog="Y" Color="" Display="Boost Error" LogReference="BoostError" RequestID="8A" Eval="0.0241*x-3.087" Unit="psi" MetricEval="" MetricUnit="" ResponseBytes="1" GaugeMin="-5" GaugeMax="5" ChartMin="-5" ChartMax="5" ScalingFactor="1" Notes=""/>
<DataListItem DataLog="Y" Color="" Display="WGDC Correction" LogReference="WGDCCorr" RequestID="8B" Eval="0.5*x-64" Unit="WGDC%" MetricEval="" MetricUnit="" ResponseBytes="1" GaugeMin="-50" GaugeMax="50" ChartMin="-50" ChartMax="50" ScalingFactor="1" Notes=""/>
<DataListItem DataLog="Y" Color="" Display="Boost Error" LogReference="BoostError" RequestID="8A" Eval="0.0241*x-3.087" Unit="psi" MetricEval="" MetricUnit="" ResponseBytes="1" GaugeMin="-5" GaugeMax="5" ChartMin="-5" ChartMax="5" ScalingFactor="1" Notes=""/>
<DataListItem DataLog="Y" Color="" Display="WGDC Correction" LogReference="WGDCCorr" RequestID="8B" Eval="0.5*x-64" Unit="WGDC%" MetricEval="" MetricUnit="" ResponseBytes="1" GaugeMin="-50" GaugeMax="50" ChartMin="-50" ChartMax="50" ScalingFactor="1" Notes=""/>
Oct 2, 2007, 03:47 PM
#118
mrfred,
Why did you set-up the range on the BEC table from 3.1 to -3.1? Why not use the stock range? Just curious
When I modified the xml file, I noticed that the TBEC table (the one that I use for load based boost) also changed its range. I had to make two xml files/base files and swap them around to get around this issue.
Why did you set-up the range on the BEC table from 3.1 to -3.1? Why not use the stock range? Just curious
When I modified the xml file, I noticed that the TBEC table (the one that I use for load based boost) also changed its range. I had to make two xml files/base files and swap them around to get around this issue.
PM me for it
Oct 2, 2007, 05:52 PM
#119
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I have been tunning my boost and I am having some trouble. I turned off correction and set BWGDC in 3rd gear and got the boost to a pretty good point. Then I turned back on correction but here is my problem.
Boost in 1st and 2nd are to low. Boost in 5th is way to high.
I have done a bunch of logs, and taken some screen shots of the troubled areas, then I wrote on each image saying what I think is the issue in that log. If you guys could please take a look at these few pulls and see what you can suggest.
Thanks
http://www.skidmore.edu/~a_blaker/Logs/JDM/
Boost in 1st and 2nd are to low. Boost in 5th is way to high.
I have done a bunch of logs, and taken some screen shots of the troubled areas, then I wrote on each image saying what I think is the issue in that log. If you guys could please take a look at these few pulls and see what you can suggest.
Thanks
http://www.skidmore.edu/~a_blaker/Logs/JDM/
Oct 2, 2007, 06:34 PM
#120
I tried to look at the logs, but the files were pretty hard to get good info. From your tables, it appears that the target boost is about 24.5 psi, but with the correction disabled, you're only hitting at best 23.5 psi. If that's correct, then you'll dial in the BWGDC table better than that (+/- 0.5 psi across the rpm range) in third gear with the correction disabled. It can take a while to dial-in the BWGDC table. I spent a few days on mine.
You'll never hit the target boost in 1st gear. Things happen too fast. It should be possible to get close in 2nd gear. 3rd thru 5th (6th) should all be pretty much the same boost across the rpm range.
Can you post a log for the run in 3rd gear with correction disabled?
You'll never hit the target boost in 1st gear. Things happen too fast. It should be possible to get close in 2nd gear. 3rd thru 5th (6th) should all be pretty much the same boost across the rpm range.
Can you post a log for the run in 3rd gear with correction disabled?