It's basically the same as your Raser laws, just a different name and different penalties. But the concept is the same in terms of harsher penalties for being 50km/h over the limit.

The nomenclature of "stunt driving" (performing dangerous, irregular maneouvres for the fun of it) or "street racing" (racing dangerously on public streets with regular traffic present and ignoring limits, signs, and signals) laws is because these were the motivations given for enacting these limits in the first place. That rhetoric caught on and became how people refer to these limits in everyday conversation regardless of whether the limits actually do anything to combat these activities.