Is it a new GT3 Cup or 911 RSR? Only time will tell.

The 911 GT2 RS is the most hardcore Porsche you can currently buy. Equipped with a 690-horsepower (514-kilowatt) engine and the ability to sprint to 60 miles per hour (96 kilometers per hour) in just 2.8 seconds, few cars compare in terms of overall raw performance. We should know, we've driven it. But even GT2 RS appears to be no match for the mysterious Porsche race car caught here on video.

Catch a glimpse of the new 911:

Though the prototype shares many of the same cues with its GT2 RS and its GT3 sibling, there are a few added features to take note of. The hood now comes equipped with three massive vents, a tow hook can be seen on the front grille, and instead of road tires, the car has been fitted with a set of racing slicks. Oh, and did we mention that massive rear wing?

It’s still unclear exactly what this prototype is – our best guess is either a new version of the 911 GT3 Cup, or a new 911 RSR. The styling of the prototype lends itself more to the former. The outgoing version of the 911 GT3 Cup came equipped with the same 3.8-liter six-cylinder engine, tuned to produce just 460 hp (338 kW). The RSR, meanwhile, uses the same engine to pump out as much as 510 hp (375 kW) depending on the restrictor.

The same 3.8-liter engine is likely found under the hood of this prototype. But if you listen closely, the 911 gives off a unique sound on hard braking. Is it possible that Porsche could be implementing some type of KERS-style technology similar to the LaFerrari FXX K? That remains to be seen.

If this prototype turns out to be either of those hardcore Porsche racers, this could spell the last hurrah for the current generation of the 911. Spy photos have suggested that a new 911 is already in the works. We’ve even gone so far as to render the proposed new model in a few varying trims, including Turbo, Cabrio, and even Hybrid.

Source: YouTube