Ok i dont have the Turbo 4G93 i have the non turbo and here are some mods that are proven to give more fire to the pot.
1)K&N Filter (for some reason i dont know why)
2)Destroy the cat converter (either punch some holes in it or put a pipe at that section)
3)You can install an aftermarket exhaust with a cone filter but u will have to use one of these with the air sensor to tune it to suit
http://www.amazon.com/Dual-Edge-MAP-Sen ... 842&sr=8-24)If you are bold like me u can install an HHO kit maybe one like this
http://www.advancedhho.com/product-p/dc45sys.htmForget about the fuel saving stuff for now but it does give u some more fire especially when tuned to suit.
5)And finally change the exhaust barrel ,dunno if the turbo cars come with a performance barrel but if it doesnt put in one.
6)I dont advise changing the spark plugs because they mess up the GDI settings and u will get problems,i guess what u can do is go with the extra pump and control it to suit.
7)The guys in china are changing the engine parts as well with lighter ones but i dont kno too much about that.(Pistons etc)