Boost

Overboost

When actual boost pressure exceeds the target. Can be intentional (brief overshoot) or dangerous (wastegate failure, boost creep).

Why it matters

Brief overshoot during spool is normal. Sustained overboost means the boost control system has lost authority.

What to look for

Transient overshoot of 1-2 PSI during spool is normal. Sustained overshoot above 3 PSI is a red flag.

Related terms

Boost Creep

When actual boost exceeds target and the wastegate can't bleed enough exhaust to control it. Dangerous at high RPM.

Wastegate Duty CycleWGDC

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

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