Spool
The turbo building up to target boost pressure from idle or cruise. During spool, boost is low, WGDC is high, and deviation from target is large. All completely normal.
Why it matters
The scoring engine excludes the spool phase (below 90% of target) from boost deviation analysis. Without this, every log would show false boost deviation during the first 1-2 seconds of a pull.
What to look for
Spool time is reported as a metric (milliseconds). Faster spool = turbo responds quickly. Slow spool could mean a larger turbo, worn bearings, or exhaust restriction.
Related terms
The percentage difference between actual boost pressure and the ECU's requested target, measured after the turbo has fully spooled.
How hard the ECU is working to keep the wastegate closed and maintain boost. 0% = fully open, 100% = fully closed.
How long it takes the turbo to reach target boost from low RPM. Affected by turbo size, exhaust flow, and wastegate behavior.
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