The ever-expanding Porsche 911 family tree has a new member, a wild child born of a tryst between the 911 GT3 RS road car and the GT3 RSR racer. The 2011 911 GT3 RS 4.0 is a halo performance machine, limited to just 600 units worldwide. It will likely be the last 997 series variant, as a new 911 is waiting in the wings.
Porsche set the stage for the RS 4.0 as nothing less than an all-out performance machine, noting that it packs the largest displacement engine ever to come in a factory-baked 911. As the name suggests, that engine is a 4.0-liter version of Porsche's flat-six, equipped with forged pistons, titanium connecting rods, and the same crankshaft as found in the GT3 RSR racer. The result is a solid 500 horsepower at 8250 rpm (and an eyebrow-raising 125 horses per liter), with 339 pound-feet of torque available at 5750 rpm and a power-to-weight ratio of 5.99 lbs/hp.
The car is, natürlich, fitted only with a six-speed manual transmission, which has gear ratios specifically designed for track work. Porsche says the car can hit 60 mph in 3.8 seconds and 124 mph in 12.0 seconds, with a maximum velocity of 193 mph. Of course, those are the exact same benchmarks as Porsche specifies for the standard GT3 RS, which offers 450 horsepower from its 3.8-liter flat-six. That means the 4.0's quoted times may be on the conservative side, but we'll have to wait until we're offered some track time with a RS 4.0 to know for certain.