Low Boost Issue with Tune

   #21  

WordBank

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I don't know if I agree with this and would expect an increase in boost momentarily......... before a throttle closure if that is the case.
The logs are actually terrible, they start 2/3 of the way through the power band and there is a shift. You can't tell therefore cannot say that it didn't reach a higher boost level from what is shown, other than the op saying it only goes to stock boost. These ecus will close the throttle for numerous reasons, doesn't even require an overboost condition. Some of them do it 100% stock for torque smoothing.

Ignoring for a second that stock and tuned are requesting the same boost (which is a stock level of boost for a TTRS)... If (op will need to confirm) the one and only change between the stock logs and the tuned logs are the tune and they are actually producing the same level of boost then there was no hardware changed/fixed but the car runs better, that means tune. The tuned file is running a clamped wastegate and the stock file is actually controlling the wastegate at the same requested boost with just a software change.


As stated.......... it's a hardware issue or FOD and most likely not tune related, since it ran fine from spring till about now according to the OP.
Where did the OP state it ever worked fine on the tune? The very first line states this is an on going issue that has never resulted in higher than stock boost levels.

UM is also an adjustable boost program, so something may be going wrong there.


3rd or 4th gear pull from 2k to redline with actual/requested boost and duty cycle would be a good start to actually see what the car is doing, you can't tell from these logs. Then confirm the throttle is open and the timing is sane.
 
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   #22  

Jack@European_Parts

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Where did the OP state it ever worked fine on the tune? The very first line states this is an on going issue that has never resulted in higher than stock boost levels.
Hello Chris......:)

As aforementioned post #5

The OP didn't say he had the problem right after getting tuned.........just what I see and can deduce from the limited logs and information.

I do agree logging the values and looking at TA would be a good idea.
I still see cars which are doing this with an open TV, and it was a turbo which couldn't achieve the higher boost, & due to the exhaust PSI overwhelming the WG spring tension hold.

There seems to be something that takes place, when running that much more rich, with timing for all tunes.
This causes the PSI in the compressor housing to rise resulting in opening the WG "mechanically", regardless of duty cycle.
( Yet another thing I find completely ignored in tunes to allow for use of manual boost controllers )

Respectfully .......maybe if tuners didn't delete the deviation tables to report a boost map DTC, or misfire from knock etc., it would be easier to diagnose.
The real reason they don't is shear laziness, because they want the customer to be able to install different size intercoolers, and have one tune.

The reality is the CAT can be damaged due to this for flow rates, and when it does, it never gets reported for that further DTC being deleted, & because it's now plugged partially.

Logging the rear OXS will usually also net a response time to indicate this in comparison to the front OXS , however, most don't know how to look at the data; and rely on the DTC's they never see, being further confused....example is the OP.
 
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WordBank

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The OP didn't say he had the problem right after getting tuned.........just what I see and can deduce from the limited logs and information.
Post 1:


Tried various boost settings but never providing available boost level and boost levels available never go beyond stock boost!

Post 5 doesn't state anything about it ever working just a time line of when the car was purchased and when it was tuned. The fact remains is that the tune is only requesting stock boost levels according to the incomplete logs. It may have worked fine first, the op will need to confirm, neither of us can actually determine if it ever ran right from what has been stated.

Respectfully .......maybe if tuners didn't delete the deviation tables to report a boost map DTC,
I agree, no one is deleting them as that isn't how it work, but what is done is in many cases too much. The ecu should still be able to have 100% of the fault codes available even if maybe some wiggle room in what triggers them is added.

or misfire from knock etc.,
You are going to have to take that up with Bosch/Siemens, wrong tree, this is disabled stock in many ecus and not something I've seen anyone actually doing. aftermarket. Messing with knock controls, yes, many applications trigger knock control stock even with zero actual knock. Messing with misfire controls, yes, but really to fix factory issues and in ways that factory revisions have also done. Messing with knock based misfire controls, nope.


The real reason they don't is shear laziness, because they want the customer to be able to install different size intercoolers, and have one tune.
Actually it is ignorant end users who fixate on boost levels that forced this sort of thing. Even stock late model applications will go so far to target a power level and not a boost level that they can run 20-30% less boost in cold weather, customers notice this on their gauge and think the car is broken. By altering the software to be more boost dependent you get more consistent boost readings year round and day to day. It becomes more obvious that there is a problem that isn't just it is 20 degrees colder outside so the car shifted to be more ignition dependent for the requested load/torque.


Karnut, the UM boost adjustment should work in a manner that you actually put in the requested boost. So for example in the tuned log request 2130mbar I believe you would enter a setting of 213 correct? Since you mentioned that boost was adjusted and no change was seen on the log of 2130 requested (sorry if it was slightly different) what was the setting you had entered for the boost adjustment in the UM tune?
 
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