I think you've missed the point. What i'm saying is that stage 2 on an hdi puts a lot of stress on the head due to increased heat and back-pressure, to a large extent this resticts the power. Fitting a hybrid turbo doesn't help with this issue, instead it compounds it further and rather than getting a good gain from it, like many of the vag fanboys see, you will only see an increase of a few horsepower. Not only that you will be putting the head under even more stress. Tbh now knowing you're still running a stock diameter exhaust i'd emphasise that even more, the way you're going is just a recipe for killing a head every 10k.
What makes you say you can't get a bigger turbo than stock without going gearbox-mounted?
What makes you say you can't get a bigger turbo than stock without going gearbox-mounted?