how-to: ECU-based direct boost control
Sep 8, 2007, 07:52 PM
#37
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I started using EvoScan 1.0 alpha and it seems to work fine. I believe it has a "boost" function already defined - and looking at the equation it seems to be the same and call the same reference.
Sep 10, 2007, 04:52 PM
#38
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So I flashed my ECU for direct JDM MAP sensor boost control today before I left work. I then logged on my way home from work. I haven't changed any of the values in my MWGDC/BDEL table. I did change my Boost Adder value to be atmospheric pressure.
I guess my question is, why am I boosting lower with this change, and why is my logged boost error value pretty much always ~-3psi, but the ECU doesn't seem to do anything to correct it. It tries to correct a little near red line, but that's about it.
Here's my graphed logged data and my relevant ROM settings...
This is with a #65 pill at the turbo and the stock pill by the BCS. Did my boost get lower because I lowered the boost adder value? If the target is ~21-22psi, but actual boost is only 19psi, and boost error is -3psi why doesn't the ECU correct using the BCS? Maybe I'm missing something... thanks!
I guess my question is, why am I boosting lower with this change, and why is my logged boost error value pretty much always ~-3psi, but the ECU doesn't seem to do anything to correct it. It tries to correct a little near red line, but that's about it.
Here's my graphed logged data and my relevant ROM settings...
This is with a #65 pill at the turbo and the stock pill by the BCS. Did my boost get lower because I lowered the boost adder value? If the target is ~21-22psi, but actual boost is only 19psi, and boost error is -3psi why doesn't the ECU correct using the BCS? Maybe I'm missing something... thanks!
Sep 10, 2007, 06:22 PM
#39
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OK... so upon studying the problem further, I'm thinking that it's my TBEC table that's causing lower boost. When the ECU is seeing ~3psi low boost, it looks to the TBEC table for how to correct it. The table has a value of -3.1psi -> 0. So this means that when the boost is -3.1psi dow, don't do anything to correct it.
It's only when the boost is only -1.9psi low or less that the TBEC table tells the ECU to correct it. That's why it begins to correct near redline.
I set my TBEC table this way as this is what mrfred recommended in the instructions at the beginning of this thread, probably rightfully so to make sure that there wouldn't be an overboost problems with this mod. So I think I'm going to revert back to the TBEC table that I was using before and see what I get. Someone please correct me if my thinking is flawed here.
It's only when the boost is only -1.9psi low or less that the TBEC table tells the ECU to correct it. That's why it begins to correct near redline.
I set my TBEC table this way as this is what mrfred recommended in the instructions at the beginning of this thread, probably rightfully so to make sure that there wouldn't be an overboost problems with this mod. So I think I'm going to revert back to the TBEC table that I was using before and see what I get. Someone please correct me if my thinking is flawed here.
Last edited by RedV; Sep 10, 2007 at 06:25 PM.
Sep 11, 2007, 07:33 AM
#41
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What is the maximum boost you could control with this system.
Also with the proper scaling values, would this be able to work with the motorola boost sensor described here
https://www.evolutionm.net/forums/sh...light=motorola
It is much cheaper than the JDM sensor.
Also with the proper scaling values, would this be able to work with the motorola boost sensor described here
https://www.evolutionm.net/forums/sh...light=motorola
It is much cheaper than the JDM sensor.
Last edited by dudical26; Sep 11, 2007 at 07:40 AM.
Sep 11, 2007, 08:00 AM
#42
What is the maximum boost you could control with this system.
Also with the proper scaling values, would this be able to work with the motorola boost sensor described here
https://www.evolutionm.net/forums/sh...light=motorola
It is much cheaper than the JDM sensor.
Also with the proper scaling values, would this be able to work with the motorola boost sensor described here
https://www.evolutionm.net/forums/sh...light=motorola
It is much cheaper than the JDM sensor.
Sep 11, 2007, 08:18 AM
#43
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In my experience, load tends to fall off somewhat in hotter weather (although load for fuel is not as temperature sensitive as load for boost), and when using a load control system, this results in more boost in hotter weather. With direct boost control, I get the same boost no matter what the weather conditions.
Sep 11, 2007, 08:48 AM
#45
Yea they are only available from mrfred. Even though it seems the motorola is working fine, I will end up buying one just to have also, but I just wanted to try a diff sensor to see what it does and have another option. But we gotta support mrfred for the work he does.