Quote:
Originally Posted by DWR
Attachment 1144667
TDI, it looks like the boost in the lower rpm range has "softened", compared to a stock curve. Looking at some old log files of mine, for an unmodified car.
The maximum at the lower end is higher than yours and the upper end is, of course, lower. I am thinking the EGW parameters needed to control the flow of the LP turbine are going to be different than the HP turbine.
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Hmmm, there might be some misunderstanding of the various plots then.
If you look back on page 3 post 53 you'll see I was able to adjust the boost controller such that the low rpm boost was not "softened" and it also kept the upper rpm boost, where the big turbo is coming online, in check. So it is working across the whole rpm band and with both turbo's and it's also verified with the analog gauge behavior.
If you're referring to the latest plot above with the BMWhat logged "low pressure turbo" setpoint. This is the big turbo and shows what the DDE would be trying to target for setpoint from that stage. That turbo doesn't start coming online until the mid/upper rpm range... I was showing that data and comparing it to what the analog gauge was showing and noted they were in very close agreement in the upper rpm range where the little turbo is being bypassed. So the logged data and the analog gauge were in excellent agreement and showing the EWG was keeping overboost in check. As well as helping keep the drive pressure to boost pressure ratio in a safe region.