Java on Truffle is an early-stage implementation of a Java Virtual Machine in Java. So far its development has focused on compatibility and functionality, not addressing performance in a systematic way. This thesis presents a series of experiments on Java on Truffle performance, namely adding Class Hierarchy Analysis, improving receiver profiling at callsites of virtual and interface methods, splitting methods per-callsite, delaying the collection of profiling information, and investigating and improving System.arraycopy performance.