TC Pressure Reached 108 PSI at Low RPM and Low TPS

[arnoldo]

Today was a great day and I was very excited as I thought today was finally the final day of datalog run to complete my big turbo swap.

To put in context, I installed CAPTS Stage-2 Turbocharger last month and I tune the calibration myself.

Peak boost in the Boost Target Normal table was 24 PSI from 4500 to 6000 RPM. Final Boost Target TBST was 25 and 25.1 PSI under TBST.

Strangely, TC Pressure hit 108 PSI, while TC target was -14 PSI (vacuum). There was also an instance when TC Target reached 65 PSI and TC Pressure was 41 PSI.

I included TC Pressure of 26 PSI and Converted MAP within 26 PSI in the screenshot and these could be an overboost situation, which took place less than 1 second.

I will definitely lower my Boost Target - Normal calibration to something around 23 PSI and set Final Boost Target at 23 PSI as well to avoid overboost and damaging CVT.

I used KTuner Non-Beta calibration so I have no Boost By Gear. I have no experience with calibration on Beta status and I want to minimize codebase error risk during tuning session.

Just to add, I have boost meter in the car and it only reached around 1.7 bar max.

I included datalog for reference.

 

[kadireren]

hi arnoldo, in my latest datalog I witnessed the same thing and I thought it was just a glitch in the software before ı saw your post. I recently removed my turbo because of a broken stud and reinstalled it.Can it be because of that? but the MAP (converted) is normal. İs it really possible for the turbo to reach that high psi? What can be the reason for it? İf it wasn't forbidden to go out at the weekends because of the pandemic, I would go and take another datalog but I had to wait for Monday. Did it happen again?

in the datalog it is between 20.00-20.10

 

[arnoldo]

hi arnoldo, in my latest datalog I witnessed the same thing and I thought it was just a glitch in the software before ı saw your post. I recently removed my turbo because of a broken stud and reinstalled it.Can it be because of that? but the MAP (converted) is normal. İs it really possible for the turbo to reach that high psi? What can be the reason for it? İf it wasn't forbidden to go out at the weekends because of the pandemic, I would go and take another datalog but I had to wait for Monday. Did it happen again?

in the datalog it is between 20.00-20.10

Which turbocharger stud that was broken? In my case, it wasn't occur once but twice although the pressure wasn't as high as 108 psi.

TC Pressure is measured on the charge pipe before throttle plate if I'm not mistaken. If ever, the sensor could be dirty or damaged.

 

[kadireren]

The stud was broken while installing the downpipe and i had left it there. Last week i decided to install the stock intercooler and stock Cat. They needed to remove the turbo to remove the broken stud. So the intercooler and the turbo was reinstalled. i wondered there was something wrong in the installation.

İn my case TC Target is also ridiculously high like 56 psi and in a wot situation. İt it is the sensör why is the TC Target also very high? Maybe it is just unimportant and random case as though there is no cel code,misfire or high knock control.

 

[arnoldo]

İn my case TC Target is also ridiculously high like 56 psi and in a wot situation. İt it is the sensör why is the TC Target also very high? Maybe it is just unimportant and random case as though there is no cel code,misfire or high knock control.

Yes. It happened to me, too. TC Target suddenly spike to 65 psi, TC Pressure went to 41 psi, steady knock control, no cel, & MAP pressure is consistent to pressure before TC spike.

Hopefullt KTuner & more experience members could share insights & opinions regarding possible issues.

 

[varge]

Hi Arnoldo, there is no way your turbocharger could produce any sort of boost (even 5-10psi) with the EWG at position 7.5 (fully open) and there is no way to build that kind of boost in a split second.
It is either a sensor or ktuner/obd glitch

What I did notice is that your EWG arm has been thrown off by 0.5 in position, where the factory fully open position is 8. This is a very small difference and should not affect your driving at all (maybe it could hurt your fuel economy by 1% or so - if at all possible to tell, right? ), but it would not hurt to have it calibrated to position 8 when no boost is commanded.

 

[kshawn]

Software glitch. No worries the car isn't actually sending boost to the moon lol.

This has happened to me several times when I was a beta tester or was running a beta version. Looks like there bug returned for this version.

 

[kadireren]

Yes. It happened to me, too. TC Target suddenly spike to 65 psi, TC Pressure went to 41 psi, steady knock control, no cel, & MAP pressure is consistent to pressure before TC spike.

Hopefullt KTuner & more experience members could share insights & opinions regarding possible issues.

As I can't go out, I looked at my previous datalogs focusing tc pressure and I saw this glitch many times. I just didn't notice before. Especially in the datalog I attached now, you can see it multiple times. So we shouldn't worry at all.

 

[KTuner]

Are these V1.2 or V2s being used? If a V2 did you see it on the display as well, or just when reviewing in the software? Thanks for the feedback.

 

[kadireren]

Are these V1.2 or V2s being used? If a V2 did you see it on the display as well, or just when reviewing in the software? Thanks for the feedback.

V1.2

 

[KTuner]

Likely other data in the stream has randomly matched the header bytes used for that packet location and the software is picking up the wrong location. We'll review and see if it can be narrowed down.

 

[arnoldo]

Software glitch. No worries the car isn't actually sending boost to the moon lol.

This has happened to me several times when I was a beta tester or was running a beta version. Looks like there bug returned for this version.

Thanks for sharing!

Hopefully the boost won't send the car to earth's atmosphere. Lol!*joke

Are these V1.2 or V2s being used? If a V2 did you see it on the display as well, or just when reviewing in the software? Thanks for the feedback.

It is 1.2 unit buddy.

Likely other data in the stream has randomly matched the header bytes used for that packet location and the software is picking up the wrong location. We'll review and see if it can be narrowed down.

Thank you very much! Let me know if you need more detail. I can send both calibration & datalog to you through email if you need them. Very appreciate it.

 

[KTuner]

This has been solved for TC related data and I added an extra check for DIFP as well, since that was reported in another thread. It may be something with other countries, as you all seem to be!

Please feel free to try the beta version available here and let me know if it's all cleared up. I'll move it to release once you confirm. KTuner.com/bta

 

[CAPTS]

sounds more like a rocket booster to me haha jokes aside yeah i think it's either a sensor malfunction or a glitch in software picking up readings.

 

[arnoldo]

This has been solved for TC related data and I added an extra check for DIFP as well, since that was reported in another thread. It may be something with other countries, as you all seem to be!

Please feel free to try the beta version available here and let me know if it's all cleared up. I'll move it to release once you confirm. KTuner.com/bta

Thank you very much for sharing the beta!

I'm not at home right now but I have downloaded the installer to my mobile in case you need to take the beta offline soon. I'll install to my laptop tonight & do datalog run tomorrow.

I'll do a quick datalog check & report tomorrow.

sounds more like a rocket booster to me haha jokes aside yeah i think it's either a sensor malfunction or a glitch in software picking up readings.

Lol! I thought I would get a free ticket to Bali for a quick weekend escape bro. Lol!

I'll do a test run tomorrow using the beta. Hopefully, the beta solves this issue.

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