CARMEL, Calif. — Porsche has finally unveiled its secretive restoration project known only as "Project Gold." While it became clear it was some sort of 993-chassis 911 , the details were kept hidden. Now we know the car in question is a 1998 Porsche 911 Turbo . The headline grabbing information is that the car has been upgraded to Turbo S specification. That means it now has a 450-horsepower version of the twin-turbo 3.6-liter air-cooled flat-six engine. It's bolted up to a 6-speed manual transmission and an all-wheel-drive system, and the entire engine and driveline were sourced from Porsche Classic's extensive inventory.Aside from the mechanical overhaul, the Project Gold 911 gets a visual update that, well, emphasizes gold. Specifically, it's Golden Yellow Metallic, the same color used on the 2018 Porsche 911 Turbo S Exclusive Series . The only black accents on the outside, though, are the wheels, door handles, rearview mirrors, window trim and air vents on the wing. Inside, almost everything is covered in black leather with bright yellow contrast stitching. The seats have also been upholstered in the same way as the Turbo S Exclusive Series, featuring yellow leather beneath perforations in the seat back to create yellow racing stripes. The dashboard features carbon fiber trim and what appears to be an iteration of the Porsche Classic stereo head unit with navigation . There's also a badge proclaiming the car's one-of-one nature. Porsche says the car has a new chassis number, too, one that comes immediately after the last 993 built.This custom 911 Turbo will be auctioned off at RM Sotheby's 70th Anniversary of Porsche auction on October 27 at the Porsche Experience Center in Atlanta. Porsche hasn't released auction estimates, but it'll undoubtedly go for quite a bit of moolah. The cash will go to a good cause, though, as proceeds will be donated to the Ferry Porsche Foundation that focuses on "education, social issues, and youth development." The one big downside to this lovely 911 is that it's not street legal, like another recently announced continuation car . So you'd better get ready to start towing it to track days to have fun with it.