No, there is not.
There's a few minor things one can do, mind - but unless your really hardcore you will not notice much difference.
You can remove the exhaust baffle for a hair more oompa, and more aggressive exhaust "note" (which I happen to like).
You can advance the timing just a tiny bit, stuff like that.
But if you really want a larger performance jump, get the two-piece BiTurbo exhaust, it's the best bang-for-buck upgrade, and is stone-simple to install.