As Porsche wound down production of its 964 Turbo in late 1993, a final batch of uncommitted coupes was sent to Porsche Exclusive for conversion to ‘S’ specification. That meant they were all equipped with the ‘Works Increased Horsepower’ X88 engine option, uprated with a larger 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 that delivered 385 hp at 5,750 rpm, 25 more than the standard 3.6 Turbo. Torque was increased to 384 foot-pounds and was available much lower in the rev range, which helped resolve the lack of urge at lower boost levels. All the X88 engines carried that special designation stamped on their alloy case, and it is believed that just 155 of these uprated engines were produced. 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-mm 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 Exclusive 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 were given variations of the exotic, hand-fabricated, and thus very expensive 935-like ‘Flat-Nose’ (or Flachbau) bodywork. There were 10 X83s 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 U.S. An additional 17 X85s were delivered with standard 964 Turbo sheet-metal and vertical headlights, dubbed ‘Package’ cars.

The American-market Turbo S coupes ordered with the X85 ‘Flat-Nose’ option added an additional $60,000 to the Turbo’s $99,000 base price. These incorporated 928/968-style retractable 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-in. wide in front and 10-in. at the rear, shod with 225/40 and 265/35 high-performance tires, respectively.

The powerful X88 engine was derived from the IMSA 3.6 race motors built by Andial for Florida-based Brumos Racing for the Bridgestone North American Supercar series. All of these Turbo S variants are brilliant performers, serving up sub-four-second 0–60 acceleration times and covering a standing quarter-mile in about 12 seconds.

The 911 Turbo S X85 ‘Flat-Nose’ on offer was completed just before Christmas on 22 December 1993. The 911 left the factory completed in Black Metallic with a Cashmere Beige/Black full leather interior. All X85s were heavily optioned, and this car is no exception, featuring Porsche floor mats in Cashmere Beige, Dark Root Wood shift lever knob, leather ignition/door key, Turbo ‘S’ ‘Flat-Nose’ package, light alloy polished wheels with Porsche crest rim caps, head restraint with Porsche crest, driver and passenger lumbar support, electric sliding sunroof, remote six-disc CD changer, and supple leather seats. A left-hand-drive example destined for North America, the car’s port of entry was Charleston, South Carolina, from which the car was then trucked across the U.S. to San Diego, California, where it was sold through Pioneer Centres Porsche. In all, with options, accessories, vehicle preparation, and destination charge, the car originally stickered for an incredible $169,273.

An original example, this car remains as it left the factory. According to the car’s CARFAX report, this is a one-owner example from new with the odometer reading 9,921 original miles at the time of cataloguing. It is supplied with its factory tool roll, Vredestein spare tire, and road-side work gloves. Additionally, it is accompanied by its Porsche-issued Certificate of Authenticity, a copy of its original window sticker, 911 Turbo 3.6 repair manual, 911 Turbo 3.6 sales brochures, period promotional materials, and even spare Turbo S decals. The Porsche manual folio houses the owner’s manual, period Porsche dealer directory, Porsche customer commitment pamphlet, operation guide, and six-disc CD player supplement.

With only 39 examples of the Turbo S X85 ‘Flat-Nose’ produced, they have always been highly sought after by collectors, and for that reason rarely come to market. This example would make an excellent addition to any discerning Porsche collection looking to add one of the rarest, most powerful, air-cooled 911s ever produced.