Bug with tables B2217 and/or B2228

[Dozerboy]

I'm running V7.5.6 build 104 on OS 52616698

I have played with these tables in the past and they didn't act right but I had made several changes so I though I had messed something up. The weather has cooled now so I've messed with them some more. Stock they manipulate boost and vane table until the ECT is over 133*. I wanted to drop that to 68* at a multiplier of 1 and 90* having 0.5. Thats not whats happening. In the morning at 55* ECT I saw no change in the vanes but going home this evening at 85* ECT until up to 190* the vanes where closed a lot more. My boost was 5 PSI higher then it should of been. When I put the tables back to stock I know the vanes where open in the evening, but don't recall what they did in the morning. I think they where closed more until the engine warmed up some, but ain't sure. I'm not sure if it both of the tables or one of them, but I'll play with them the next few days.

[bballer182]

OK, so i can't comment on B2217, however, I have never had a problem with it and it act as it should for me. Now, with B2228 there is something that you should know that will save you a lot of grief in the long run when it comes to tuning your vanes.

First look at table descriptions of B2231 and B2232. Those two tables are the reason why you are not seeing what you would expect out of B2228. Those two tables control how the ECM manages the turbo/boost. I know the definitions of those two are kind of hard to grasp and are kind of confusing, but this is what it boils down to. They basically say if at X rpm the commanded MM3 is over X amount the ECM will disregard what the desired vane position tables say and reference the desired boost tables instead. So that means also the the converse is true as well. So if at X rpm the commanded MM3 is under X amount the ECM will desrgard the desired boost and reference only the vane tables.

There is a catch though and you may already know this but to anyone else who reads this this is good information.

While the ECM will control the vanes to make X boost at X rpm at X MM3 given the MM3 is above what is in tables B2231 and B2232, it still references the vane tables in a mode, what i call quick reference mode. That means the ECM looks up what the desired vane position should be for X boost at X rpm at X mm3 and moves the vanes to that position, and if that position is incorrect then has to hunt for the position that will make the desired boost. The ECM does this very quickly. But if you have a boost table that is drastically different than what the vane table says this makes for some interesting times while the ECM "hunts" for the proper vane position all the time, and believe me it's noticeable. There is a cure for this and i have written it up either here or at dieselplace, or maybe both, can't remember. If you're interested in fixing the problem or looking for snappier performance out of your turbo search "dialing in turbo vanes" here or there.

[Dozerboy]

I forgot about those but I don't see how it could be them. I'm seeing the issue while driving running around town and hwy at up to 40mm3. And the fact that my boost changed 5psi and the only thing different is the changes I made to B2217 and B2228.

Its hard to nail it down when it doesn't get very cold here and can't do more then 1 test a day really.

[bballer182]

well those 2 tables can have a huge impact on what happens to your boost/vanes

[Dozerboy]

Well I put the vane table back to stock and it was still acting up this evening. And my ECT got to at least 192* and the boost never dropped back down that I saw. This morning the boost was high but dropped down before I hit 190*. Going to try making the vane table stock tomorrow and then I might try the the boost controls enable and disable.

My target vane tables fairly closely mach up with what I'm calling for for boost. I know I can probably tune out the high boost with tables B2216 and B2227, but would like to know they are working how there suppose to be.

[bballer182]

well if it helps at all i set my B2231 and B2232 to basically ignore the vane tables all together and focus on boost tables then dialing in the vanes after the boost tables are finished.

[Dozerboy]

Ya I think that I'm going take that route too. I screw up in my last posts. The problem is with the B2228 the vane table so you might be right about B2231 and B2232 playing a part. So when you say you set them to ignore the vane table you set them low like 2mm3 and 1mm3? I just want to make sure since it doesn't say anything about the vane table only that it "enables the ECM to control boost pressure".

Have you ever logged your truck in high idle? I have manually brought my RPMs up to 1200 and I think I was in the 5-10 mm3 range but when I idle normal it goes up to 30mm3 at times.

[bballer182]

Yeah i just set them so at idle to 1200 is stock then over 1200 is like 2mm3

[Dozerboy]

Stock from 1600RPMs up mine are set to 2/1 humm well I'll try lowering them a little from idle to 1200 too.