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Old 07-10-2012, 04:00 PM   #16
Cobb Tuning
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Member#: 4803
Join Date: Mar 2001
Location: Austin, TX
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We are certainly not dealing with an actual boost spike here - no way you are going see boost that high on the stock turbo regardless let alone a 20+ psi spike in half a second.

amalgrover has a good point - even if the sensor was defective and pegged at 5 volts, the most you would see with this car and the stock MAP sensor/calibration would be about 27 psig at sea level. Bad logging data makes the most sense here. But, I would add barometric pressure and manifold absolute pressure to your logs. "Boost" monitor in the logs is in relative pressure, but it is calculated by ECU as (manifold abs. pressure - baro. pressure). So, if there was an issue with the baro. pressure reading, it would impact the boost monitor. But, the numbers don't really jive with 37 psig (even if baro pressure was reading at 0 psi, you would have to hit 22 psig, which doesn't make sense in your first log). The calculated load monitor also shows a value over 7.5 g/rev in that line, but this is not reflected in the airflow value. That makes me think these two monitors (boost and calculated load) had bad data in the ECU's response. Can you post the log with the second example of the issue?

Bill
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