The Porsche Cayenne Turbo and its more sportily styled Cayenne Turbo Coupe sibling are two of the most thrilling driver's SUVs around. With 541 horsepower from the 4.0-liter twin-turbo V8 engine, they'll reach 60 mph in under four seconds. But Porsche is putting the final touches on an even more extreme version of the Cayenne Turbo Coupe. A report from earlier this week indicated that it'll produce around 630 hp and now Porsche has shared pictures, video footage, and some more details of this lightly disguised prototype on the track. The prototype's development coincides with a refresh of the entire Cayenne Coupe lineup.

For now, the hottest Cayenne Coupe yet - besides the Cayenne Turbo S E-Hybrid Coupe - hasn't officially been given a name but it seems likely that it'll be badged as a Turbo S since the automaker has confirmed it'll be based on the Cayenne Turbo Coupe.

Two-time World Rally Champion Walter Rohrl drove the new Cayenne Coupe and described it as a "great leap forward compared to everything that has gone before." Porsche has made numerous upgrades to the new Cayenne Coupe compared with the Turbo variant. Not only are the front rims wider by half an inch, but the 22-inch tires have a larger contact area since there has been a 0.45-degree increase in negative camber.

The new hot Cayenne Coupe also has centrally-positioned tailpipes which are different from the quad-exit pipes positioned on the outer edge of the body on the existing Cayenne Turbo Coupe. There is also a new titanium exhaust system that should amplify the sound of that V8.

"The car remains incredibly stable even in fast corners," said Rohrl. "More than ever, you have the feeling that you are sitting in a compact sports car rather than in a large SUV."

With the kind of power that this new Cayenne Coupe has on tap, it should be an even closer match for the Lamborghini Urus. A deployable rear wing is another hint at the improved aerodynamics of what should be an incredible machine to drive.