This 1994 911 Turbo S “Flachbau” is one of the rarest and most sought-after Porsches of its time, combining the best of the classic air-cooled, single-turbocharger, rear-wheel-drive Turbo era with distinctive looks and undeniable exclusivity. So it is perhaps surprising to note that the model owes its existence to a quirk of Porsche production history: As the automaker wound down production of its 964 Turbo in late 1993, and with the 993 Turbo on the horizon, a final batch of uncommitted 964 coupes was sent over to Porsche Exclusive for conversion to "S" specification.

Consequently, all were equipped with the "Works Increased Horsepower" X88 engine option, uprated with a larger, single KKK turbocharger with increased boost, a more efficient intercooler, modified cylinder heads with larger ports, increased-capacity fuel injectors, and more radical camshafts with advanced engine timing. The M64/50S X88 was an air-cooled flat-six which delivered 385 horsepower at 5,750 rpm, 25 more horses than the standard 3.6 Turbo. Torque was increased to 384 pound-feet and was available much lower in the rev range, which helped resolve the lack of urge at lower boost levels. Power was fed through a G50 five-speed manual transaxle with a ZF-sourced 40 percent locking differential.

These cars were all fitted with standard 3.6 Turbo suspension, including 21- and 22-milimeter anti-roll bars in front and rear, respectively, and Boge shocks and struts. Engineer/racer Roland Kussmaul lowered the ride height by about an inch and a half to enhance handling.

Porsche produced these special 964-based Turbo S coupes in several distinct varieties. Besides the standard Turbo S, there would be four different versions, depending on where they were to be sold; these were designated as Option X83, X84, and X85, the last of which was available in two flavors. Most, but not all, were given variations of the exotic, hand-fabricated (and thus very expensive) 935-like flachbau, or "flat-nose" bodywork.

The American-market Turbo S coupes ordered with the X85 Flachbau option added an additional $60,000 to the Turbo's $99,000 base price. These incorporated 928/968-style retractable but uncovered "flounder" headlamps, standard Turbo sheet-metal, asymmetrical 959-style air intakes on both rear quarter-panels, a special front air splitter, a louvered rear wing that enclosed the intercooler, quadruple exhaust tips, and 18-inch-diameter "Speedline for Porsche" modular light-alloy wheels, 8 inches wide in front and 10 inches in the rear, shod respectively with 225/40 and 265/35 high-performance tires.

In total, 76 Turbo S Flachbau coupes were built; 10 X83s were sold to Japan, 27 X84s offered to "Rest of the World" buyers, and 39 examples of the X85 version with flat-nose front ends were sold to the United States. An additional 17 X85s were delivered with standard 964 Turbo fenders, complete with vertical headlights.

This 1994 Turbo S Flachbau was delivered new to its first owner, an Oklahoma City resident, in July 1994 via Motorcars International of Springfield, Missouri. While its performance potential was obvious, this triple-black Porsche also received a number of luxury touches; its original specification included heated front supple leather seats with lumbar support, a power sunroof, and a remote CD changer.

Though driven only sparingly, service invoices on file illustrate the high level of maintenance this Porsche has received over the past decades. In addition to regular oil and fluid changes, mechanical systems were serviced as-needed—and careful attention was also paid to perishable rubber components and cosmetic items as well. In addition to a service file containing invoices spanning 2002–2018, this 911 is accompanied by a window sticker, a Porsche Certificate of Authenticity, an owner’s manual, and tool kit.

Offered from the Tenenbaum Collection showing just 3,700 miles at time of cataloguing, this car represents a special moment in turbocharged 911 history. The 993 Turbos that would follow gained all-wheel drive and traded the signature single large turbocharger for two smaller units; while excellent performers, they offer a driving experience very different than that of 964 Turbos such as this. For those seeking the pinnacle of classic Porsche Turbo feel, along with the added rarity of the US-specification X85 package, this low-mileage, exceptionally preserved, triple-black 1994 911 Turbo S “Flachbau” would make the for the ultimate prize.