You\'d want to adjust the airflow parameters Here is the CFG section i\'m referring to. optimalAirflow = 60 lowerAirflowLimit = 10 upperAirFlowLimit = 300 Change the lowerAiflowLimit to something around 5, i think, and optimal airflow to something around 30. You\'d need a bit of testing (OK, a lot) to fine-tune the altitude limits, but this is the basic idea.