Theoretically, you can turbo or supercharge any compression ratio, but practicaly you have to watch out for detonation of the air/fuel mix before the spark ignites it. You can put additives in the gas to raise the octane rating to a high enough value. I don't know much about the VW engine studs, but I suspect they would have to be strengthened. The heads may also need to be strengthened if you plan to drive more than a few miles.