Weight will be its biggest problem, stripping the interior is a good start.
You can also get it remapped, better exhaust and some lumpier cams, although, what is already in there is pretty good at 230bhp!
Next step would be a conversion to 3.2 GTA engine, then bore them to 3.5, 3.7 or 3.9 - all expensive stuff.
Or you could go the supercharger route
