Boost

Spool Time

How long it takes the turbo to reach target boost from low RPM. Affected by turbo size, exhaust flow, and wastegate behavior.

Why it matters

Increasing spool time over repeated logs can indicate turbo wear, exhaust leaks, or wastegate issues.

What to look for

Compare spool time across logs. A consistent increase suggests something is degrading in the turbo system.

Related terms

Wastegate Duty CycleWGDC

How hard the ECU is working to keep the wastegate closed and maintain boost. 0% = fully open, 100% = fully closed.

Boost Target

The boost pressure the tune is requesting. Actual boost should track this closely.

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