If this is Nethaniel's old wagon we're talking about, its not an sti motor. From memory it was a legacy rs block. I believe he had a v2 sti chipped ecu running it. Im not sure what ecu he sold with the car though. Getting another sti ecu to run it would probably be the go, preferably the jap ones as they have a bit more of an aggressive tune.
Also depending on what parts he sold the car with, its not going to take much to make 140kw.
Nah it's not Nethaniel's car. Funny you should say that though. I was the guy he sold it to but I sold it a week later for a $1500 profit (long story) and the ended up buying another one haha.