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Discussion Starter · #1 · (Edited)
I am somehow managing to not reach the specified boost level (or builds boost slowly) and also spiking in boost and sometimes returning back down after the spike. Car is a 2003 with a stage 1 tune, stock downpipe, stock intake and a catback. I adjusted the wastegate actuator to be stiffer or softer with no luck :confused:
 

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Please consider adding relevant information when asking your question.

We don't know WHAT car you have to start.

Do you have any datalogs to support your claim?
 

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Discussion Starter · #3 ·
Please consider adding relevant information when asking your question.

We don't know WHAT car you have to start.

Do you have any datalogs to support your claim?
My bad I thought the process would be fairly universal across ej wrxs I have yet to get a datalog but the accessport and a secondary boost gauge said it was going over and under the stock boost setting.
 

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sometimes the car makes too much boost and sometimes it barely makes boost
Show me a datalog where that happens. You can't make that judgement by just looking at flashing numbers while you are driving.

You need to log:
RPM
Calculated Load
Boost
TD Boost Error
 

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Oh, add to the above: Throttle Position. It helps clean up the data when analyzing.

If you do a couple pulls in 3rd gear (need 3000-6000 RPM) and post your log up here, I'll be able to help you further.
 
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Discussion Starter · #8 ·
Oh, add to the above: Throttle Position. It helps clean up the data when analyzing.

If you do a couple pulls in 3rd gear (need 3000-6000 RPM) and post your log up here, I'll be able to help you further.
Here is a log from 3rd gear it seems like it was over the boost level until I got a CEL for an egt sensor lol. I do have other 3rd gear logs but they were not with the exact gauge settings you suggested
 

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Were you the one in an earlier thread commenting on your Boost Controller being "crusty?" Indeed we are seeing a failure of the ECU to control the boost curve properly. Here is the result of your pull at full throttle.

328942


TD Boost Error is the measure of "Actual-target" boost and is used as the input into the boost control's PI controller. You'd expect the TD Boost Error to be high, then decrease as the load increases and hover just around zero. In your case, we can see the TD Boost Error climb sharply, then the boost control starts to properly bring the Boost back to target before falling off again.

Indeed there is a problem here, but that isn't the only issue that I noticed. Did you just reset or reflash your ECU right before the log? Your DAM is at 13 where it should be sitting at 16.

The next steps to address the boost control issue -- this is going to get a bit tricky as this could be either Electronic or Mechanical.

On the Electronic side, it could be the boost controller itself failing or the ECU mapping is problematic. If this is an OTS map, I'd ignore the latter.

On the Mechanical side, I'd start small - replace all the vacuum lines in the boost control system taking great care to retain the restrictor pill. Then I'd consider replacing with an OEM boost controller of newer vintage. Carefully separate the turbo inlet pipe from the turbo (careful, these can rip) and inspect the turbo for shaft play. A little bit of play is normal but a whole lot will cause problems. It could also be an issue with the WGA itself, but that's very rare. Finally, just to round off the testing, do a compression and leakdown test.
 
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Discussion Starter · #10 ·
Were you the one in an earlier thread commenting on your Boost Controller being "crusty?" Indeed we are seeing a failure of the ECU to control the boost curve properly. Here is the result of your pull at full throttle.


TD Boost Error is the measure of "Actual-target" boost and is used as the input into the boost control's PI controller. You'd expect the TD Boost Error to be high, then decrease as the load increases and hover just around zero. In your case, we can see the TD Boost Error climb sharply, then the boost control starts to properly bring the Boost back to target before falling off again.

Indeed there is a problem here, but that isn't the only issue that I noticed. Did you just reset or reflash your ECU right before the log? Your DAM is at 13 where it should be sitting at 16.

The next steps to address the boost control issue -- this is going to get a bit tricky as this could be either Electronic or Mechanical.

On the Electronic side, it could be the boost controller itself failing or the ECU mapping is problematic. If this is an OTS map, I'd ignore the latter.

On the Mechanical side, I'd start small - replace all the vacuum lines in the boost control system taking great care to retain the restrictor pill. Then I'd consider replacing with an OEM boost controller of newer vintage. Carefully separate the turbo inlet pipe from the turbo (careful, these can rip) and inspect the turbo for shaft play. A little bit of play is normal but a whole lot will cause problems. It could also be an issue with the WGA itself, but that's very rare. Finally, just to round off the testing, do a compression and leakdown test.
I was the one that said my boost controller was crusty but that was in a sense that it was just dirty and not broken. (at least I think) I did also do an OTS reflash and the tune has been used for maybe 50 miles and could possibly explain why the shift light does not work? I checked the turbo shaft play and it was very minimal on both axes and a compression test was done 2 months ago with 150psi on all 4. It could possible be a WGA or a hose causing this. I did swap out the WGA from a spare td04 since the one that came on the car was was abnormally stiff even when disconnected. The thing is that both actuators look the same but one just feels 3x stiffer than the other one I swapped that out for is a lot softer but the softer one may be causing the inconsistent boost?
 

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The boost control responds to the wastegate actuator -- a different wastegate actuator requires different ECU calibration.

I did swap out the WGA from a spare td04
Are you certain it was a TD04 from the same model WRX?
 

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Discussion Starter · #12 ·
The boost control responds to the wastegate actuator -- a different wastegate actuator requires different ECU calibration.



Are you certain it was a TD04 from the same model WRX?
I am not certain but I was told the turbo came from a 2002 and the car is a 2003. As I cannot confirm that I can also assume that the turbo might be from an 04-05 car since those I’ve read have softer actuators?
 
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