Wastegate basics
A wastegate lets exhaust bypass the turbine. The spring inside the wastegate actuator or external gate sets a base boost pressure. The boost controller or ECU-controlled solenoid can increase pressure above that base by managing the signal sent to the gate.
Internal vs external gates
Internal wastegates are compact and common on OEM-style setups. External wastegates often control flow better on higher-power builds or custom manifolds because they can be placed and sized for better bypass flow. External gates add cost, fabrication and heat management requirements.
Boost creep and spikes
Boost creep happens when the wastegate cannot bypass enough exhaust, so boost keeps rising at high RPM. Spikes happen when control response is too slow or the plumbing is wrong. Both issues should be fixed mechanically or in control strategy, not hidden with a risky tune.
Safe setup habits
Use quality hoses, keep signal lines short and heat-protected, use the correct porting on solenoids, confirm spring pressure, and log boost against RPM and throttle position. Stable boost is a reliability feature.