[sperry]

To run an STi motor w/o a turbo, you would basically have to tear the motor down, replace the pistons w/ higher compression pistons, and completely retune it. All to make around 170hp.

You could get the motor to start with some sort of turbo by-pass pipe, and proper termination/routing of the turbo oil and coolant lines. But it'd barely idle, make 40 hp, and probably demolish itself if you tried to drive it anywhere.

The cheapest fix is to buy a used STi turbo and swap it in there, while fixing whatever the broken turbo took out along the way. You'll need to carefully inspect the oil to make sure you didn't get anything in the block that will take out a bearing.

While you're fixing all that, I'd also go and take off any BOV, MBC, intake, etc that's on the car w/o a proper tune, because if the car had been properly setup, nothing your friend could have done shy of crashing it or missing a shift should be able to break it... especially the turbo. I can't think of a way to drive that breaks an otherwise perfectly good turbo unless the car is modified beyond its tune.