There was a 993 Turbo S. And a 996 Turbo S, too. But so far, we have not seen a Porsche 997 Turbo S. Reason? Dunno, though we imagine that a more powerful turbo would step on the toes (among other parts) of the hard rocking GT2. Especially as the fastest of all 911s "only" makes 40 more horsepower than the plain ol' Turbo. And besides, 520 horses is probably pushing pretty hard against the edge of the performance-to-reliability ratio that OEMs have to worry about (unlike, say, tuners).
Er, that used to be the case. But, with the pending release of the new 911 Turbo and its 500 hp newly enlarged 3.8-liter direct injected flat-six, 520 horses doesn't sound like a lot. Just doin' a bit' o' speculatin' here, but if Porsche was able to squeeze 520 ponies out of the old motor in the 3.6-liter, well then, they could certainly squeeze who knows how much out of a special edition of the new one without boiling the water-cooled turbines.
According to Team Speed, a new 997.5 Turbo S is coming, and coming soon. When? Spring 2010. And how much power? Pure speculation, but 540 to 550 hp sounds about right. And figure on standard ceramic brakes, RS-style center lock wheels, and some sort of unique bodywork (more strakes?) to differentiate it from mere mortal Turbos. But like all rumors, this could prove totally false. But if it's true, look for the Porsche Turbo S to going up against Nissan's similarly steroidal Godzilla GT-R Spec-V on that one road in Germany...
[Source: Team Speed]