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Quick highway pull shows suspicious MAP readings in log.

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Old 09-10-2018, 11:16 PM
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Default Quick highway pull shows suspicious MAP readings in log.

Did a quick 4th gear pull on the highway to check AFRs at boost, but when i checked the log, it shows erratic MAP readings. Im worried this could be a sign of preignition. anyone have experience with this anomaly? fluctuates between 160-170 kpa, as the attached photo suggests.
Attached Thumbnails Quick highway pull shows suspicious MAP readings in log.-graph.png  
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Old 09-11-2018, 01:50 PM
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The difference between 160 and 170kpa is 1.45 psi. It's probably your wastegate door not holding steady and oscillating as a result of your timing fluctuating so much. Reduce the difference between rows in that area and see if it doesn't settle down.
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Old 09-11-2018, 05:44 PM
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It basically mirrors your timing.

Impressive.
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Old 09-11-2018, 06:42 PM
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Originally Posted by Erat
It basically mirrors your timing.

Impressive.
First thing I noticed as well.
OP, post log and tune...
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Old 09-11-2018, 10:31 PM
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My point was if your tune is such that 1.45 PSI will make a significant swing in your spark timing then that is likely the source of your oscillation.
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Old 09-12-2018, 07:59 PM
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Tune and log attached. I tried to make a smooth slope in the timing as boost is increased. If your responses are anything to note, it looks like the slope could be too steep?
Attached Files
File Type: msq
Toon.msq (108.3 KB, 39 views)
File Type: msl
2018-09-09_20-04-06.msl (74.1 KB, 40 views)
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