1992 Porsche 968 Turbo RS

The first of the Porsche family's front-engined sports cars was the 924 of November 1975 and drew heavily on Volkswagen and Audi components. Its 2.0-liter, four-cylinder, overhead-camshaft engine was a development of the Audi 100's and Volkswagen's spare parts bin was scoured for a four-speed transaxle transmission. The 944 model followed six years later and was constructed along similar lines to its 924 progenitor. The wider bodywork concealed a 2.5-liter, overhead-camshaft 'four' (essentially half of the 928's V8 bored out and given twin balancer shafts to minimize the vibration). The engine was paired with a five-speed rear transaxle and the 924-type running gear was modified to cope with the 944's enhanced performance.

The Porsche 924 was produced through 1988; the four-cylinder 944 from 1982 to 1991; and the V8-powered 928 from 1977 to 1995. The Porsche 968, produced from 1991 through 1995, was styled along the 928 lines and retained its 944 predecessor's basic mechanical layout. Its specification was enhanced via a 2,990cc engine paired with a six-speed manual transmission. It had a 104mm bore, an 88mm stroke, a compression ratio of 11.0:1, and a lighter crankcase, crankshaft, and pistons. With 'Variocam' variable valve timing, updated engine management electronics, and a dual-mass flywheel, the engine delivered 240 horsepower and endowed the 968 with a zero-to-sixty mph time of 6.2 seconds and a top speed of 156 mph. Porsche's dual-model four-speed Tiptronic automatic transmission was optional equipment.

The styling by Harm Lagaay had a familiar family resemblance to the top-of-the-line 928, including its integrated front bumper and exposed pop-up headlamps. The rear of the car received more extensive styling updates with fully coloured rounded taillamps, PORSCHE badging was fitted between the taillights, and the rear apron was integrated into the rear bumper.

The Porsche 968 CS (Club Sport) and Turbo S

968 CS
The Porsche 968 CS was a lightweight version of the 968 designed for an improved track experience. Many of the luxury amenities were removed, along with the sound-deadening material, rear wiper, vanity covers in the engine bay, and the power windows were replaced with crank-driven units. There were manually adjustable lightweight Recaro racing seats and a three-spoke sports steering wheel with no airbag. The sunroof and A/C system were optional. There were no rear seats.

Mechanical improvements included a revised suspension system lowered by 20 mm, and wider wheels and tires installed. The 16-inch wheels were wrapped with 225 at the front and 255 tires at the rear.

968 Turbo S

Porsche Motorsports at Weissach produced a turbocharged 968 Turbo S in exclusive quantities (14 in total) using the same body and interior as the Club Sport. The 968 Turbo S was distinguished by its adjustable rear wing, three-piece speedline wheels, deeper front spoiler, and NACA bonnet (hood) scoops. It weighed 45 lbs (20 kg) less than the standard 968 and its suspension was lowered by 17.8mm (0.7 inches). The largest improvement was underneath the hood - its 3.0-liter engine (type number M44/60) with a 944S2 style engine block and an 8-valve SOHC cylinder head from the 944 Turbo S. With 305 horsepower (227 kW) at 5,600 RPM and 369 lb-ft of torque at 3,000 RPM, the 968 Turbo S was capable of sprinting from zero-to-sixty mph in 4.7 seconds. The six-speed transaxle received a longer final drive and gear ratios, along with a 75% locking limited-slip differential.

The ride height was lowered, stiffer springs and revised damper settings were applied to the suspension, and stopping power was by four-piston brakes.

The Porsche 968 Turbo RS

The Porsche 968 Turbo RS was a higher specification, more potent, and lighter version of the Turbo S. Built by Porsche Motorsports Research and Development, the 968 Turbo RS was built between 1992 and 1994. Two variations were offered including one built to the German ADAC GT specification, weighed 1,350 kg, and equipped with the K27 turbocharger from the Turbo S and offering 337 horsepower. The international specification version weighed 1,212 kg and used a KKK L41 turbocharger and produced 350 horsepower. Both variants received a modified six-speed manual transmission with a racing clutch and altered gear ratios. To cope with the demands of motorsports, the suspension was appropriately modified.

The minimalistic interior included a roll cage and a single racing bucket seat with six-point harness.

Four examples of the Porsche 968 Turbo RS were built. Accolades include a fourth-place finish in the Avus race in 1993 by the Joest team with driver Manuel Reuter. In BPR competition, a sixth place finish was achieved at the 4-hour race by Dijon in 1994. The Seikel Motorsport team used a 968 Turbo RS at the 1994 24 Hours of Le Mans, driven by John Nielsen, Thomas Bscher and Lindsay Owen-Jones. After 84 laps, it was forced to retire due to an accident.

by Daniel Vaughan | Jan 2023