Alright mate, I've said a few things about this to your bro before when we've been talkin about cars, not sure if he's mentioned any of it to you though... Someone was selling a TD04 turbo you could buy that and a new exhaust manifold as the standard one is restrictive, and a front mount intercooler cus the top mount is pants. Obviously not as simple as that but those are a few things you could do.