There seems to be almost no limit to the degree that Porsche’s engineers can extract more horsepower and torque from its venerable boxer-six engine. Perhaps the most astonishing product in recent years has been the unworldly GT2 RS, of which only 500 were produced for the 2011 model year. Establishing a target of a 7 minute, 27 second lap time at the Nürburgring Nordschleife circuit – two seconds quicker than Walter Rohrl had lapped with a modified GT2 in 2006 – Porsche nicknamed its project “727” to keep that goal top of mind.

The answer, as always, was pretty basic: reduce weight and add more power. For the first, Porsche started with what had been its fastest and quickest 911, the GT2, which scaled about 3,175 pounds, and trimmed that to 3,021 pounds dripping wet, through use of carbon-fiber body panel and trim parts inside and out. A new version of the twin-turbo, four-cam six-cylinder developed for the GT1 Le Mans race car was fitted with new four-valve heads, Variocam-Plus, and variable-turbine technology, and massaged to produce an eye-watering 620 horsepower and 516 foot-pounds of torque.

This package could launch the GT2 RS to 60 mph in an official 3.3 seconds, but many reviewers claimed that was a conservative figure. One hundred mph came up in less than 7 seconds, and given room to run, the GT2 RS could touch 209 mph. The bright yellow calipers visible through the spoked 19-inch-diameter alloy wheels state that the car is equipped with Porsche’s fantastic carbon-ceramic composite (PCCB) brake system. There’s also stability control and PASM, Porsche’s adaptive suspension system. The car was fitted with an extensive aero kit that included a huge bi-plane rear-deck wing.

When it came time to wring out the GT2 RS, factory test driver Timo Kluck turned in a hot lap of 7 minutes and 18 seconds, quicker than even Porsche’s fabled Carrera GT could muster.

This 2011 GT2 RS comes from a private collection and has been driven only 3,232 miles from new. It is number 472 of the 500 cars built, and it is tastefully appointed with silver paint offset by a natural-look carbon fiber front hood, mirror housings, and side intakes. The interior is trimmed with leather, and the rear compartment is fully carpeted. Rather than the standard fixed racing seats, this car has the optional and more practical, electrically adjustable sport seats.

Supplied with its original documentation, option list (totaling $16,350), and other as-delivered items, here is a rare opportunity to acquire a mint-condition GT2 RS, one of the rarest and certainly one of the quickest and fastest street-legal automobiles to ever emerge from Zuffenhausen.