Performance Tuning Enterprise 4.5

Does anyone knows how to redirect an adapter standard error/output?

I am trying to fine tune the Java Heap Size memory allocated to each adapter process and need to see how often the Garbage collector (GC) is running
Enabling the JVM option to generate GC messages is not a problem as I can see GC messages logged when I run an adapter in debug mode.
However, I need to analyze the behaviour in normal mode and for extended periods of time

Any help/commentary is highly welcome