In a remarkable fusion of racing heritage and modern-day engineering, Porsche has introduced the 963 RSP, a one-of-a-kind street-capable hypercar commissioned by motorsport luminary Roger Penske. Built directly upon Porsche’s championship-winning LMDh 963 race prototype, this bespoke machine channels the legacy of the legendary Porsche 917 street car commissioned by Count Rossi half a century ago.

Porsche started a daring experiment in the spring of 1975 when it converted one of its powerful 917 racing cars into a road vehicle for a cutting-edge client.  The man behind this bold endeavor was Gregorio “Count” Rossi di Montelera, a passionate motorsport lover and the heir to the Martini & Rossi company.  His only requirement when he went to Porsche's Weissach factory was to create a 917 that could be driven on public roads.

Porsche selected 917 chassis #030, initially a factory test and endurance-race car, and overhauled it for street duty. The modifications were minimal yet meaningful: addition of rudimentary exhaust mufflers, side mirrors, turn signals, a horn, and a spare tire under the rear deck. Inside, the stripped-down cockpit gained tan Hermès leather seats and suede accents—a rare comfort in an otherwise uncompromising machine.

Once restored, the 917 donned Martini Silver livery, mimicking its racing heritage, and was registered in Alabama—after Porsche couldn’t secure European street certification—to legally drive through public streets. Its maiden voyage wasn’t around the block; instead, it took the legendary journey from Zuffenhausen to Paris—hundreds of miles of asphalt and ambition.

Today, this singular Porsche 917 remains a living legend—preserved in its original form, still driven occasionally in southern France, and displayed at major events like the Goodwood Festival—an enduring testament to what happens when automotive royalty meets engineering bravado

From Le Mans to Lane-Driven Reality

The transformation from racetrack icon to street-worthy roadster involved precise, thoughtful modifications:

A potent 4.6liter twin-turbo V8 hybrid (originally from the 918 Spyder and race-developed by Penske) now simmers world-class performance—roughly 671 hp—and has been tuned to run on standard pump gas.

Ride height has been raised, dampers softened, and lighting systems upgraded to meet minimal legal criteria, including headlights, turn signals, and license plate fittings.

Inside, the cabin balances raw racing with refined luxury—soft tan leather, a helmet and steering-wheel storage panel, and nods to the iconic 917’s design DNA.

Symbolism in Silver

Count Rossi's iconic 917 is the inspiration for the car's "Martini Silver" livery, which is sprayed over carbon-fiber and Kevlar bodywork.  The nose is adorned with an enamel Porsche emblem, and certain aerodynamic adjustments guarantee that it will continue to perform as it has in competition on public roads.

The One-Off Prestige

Porsche's decision to craft just a single 963 RSP preserves its exclusivity. The company secured an EPA exemption in the U.S. for emissions compliance and obtained special permission to drive during public events like Le Mans, though the car is not fully homologated for unrestricted street use.

The 963 RSP is a custom statement that combines contemporary WEC and IMSA-bred performance with a daring, groundbreaking act from fifty years ago. It is neither only a race vehicle nor a GT.  Similar to how Count Rossi's 917 broke the rules, the 963 RSP follows that tradition by demonstrating Porsche's commitment to respecting its history while pushing the envelope in the future.