Porsche 944 S2 Cabriolet

The Porsche 944 is a sports car built by Porsche from 1982 to 1991. It was built on the same platform as the 924, although 924 production continued only until 1988. The 944 was intended to last into the 1990s, but major revisions planned for a 944 "S3" model were eventually rolled into the 968 instead, which replaced the 944. The 944 was a successful model and was available as both a coupé and cabriolet in naturally aspirated and turbocharged forms.
The Porsche 924 had originally been a project of VW-Porsche a joint Porsche/Volkswagen company created to develop and produce the 914 which was sold in Europe as both a Porsche and a Volkswagen. In 1972 a replacement for the Volkswagen version of the 914, code named EA-425 began development. The model was to be sold as an Audi as part of the VW-Audi-Porsche marketing arrangement. Although testing had begun in the Spring of 1974 Volkswagen decided to cancel the program due to the expense of production as well as the feeling that the recently released Volkswagen Scirocco would fill the sports coupe sufficiently. At the time Porsche was considering introducing their own water-cooled front engine 2+2 coupe to replace the 912E and their model of 914 and Volkswagen's cancellation provided an opportunity. Porsche purchased the design and the finished development with an Electronic Fuel Injection system. The vehicle drove and handled exceptionally well and received positive reviews, but was criticized for the Audi-sourced 2-litre engine; Later in 1979, Porsche introduced a Turbocharged 924 to increase performance, but the price was considered too high for the time, which hampered sales. Rather than scrap the design, Porsche decided to develop the 924, as they had with generations of the 911; although model numbers would change, the 924 would provide the basis for its replacement.
Porsche re-worked the platform and abandoned the Audi engine, installing in its place its own freshly designed all-alloy 2.5-litre straight-4 engine, bore 100 mm (3.9 in), stroke 78.9 mm (3.1 in), that was, in essence, half of the 928's 5.0-litre V8, although very few parts were actually interchangeable. Not a natural choice for a luxury sports car, a four-cylinder engine was chosen for fuel efficiency and size, because it had to be fitted from below on the Neckarsulm production line. To overcome the unbalanced secondary forces that make other four-cylinder engines feel harsh, Porsche included two counter-rotating balance shafts running at twice engine speed. Invented in 1904 by British engineer Frederick Lanchester, and further developed and patented in 1975 by Mitsubishi Motors, balance shafts carry eccentric weights which produce inertial forces that balance out the unbalanced secondary forces, making a four-cylinder engine feel as smooth as a six-cylinder. The engine was factory-rated at 150 hp (112 kW; 152 PS) in its U.S. configuration. Revised bodywork with wider wheel arches, similar to that of the 924 Carrera GT, a fresh interior and upgrades to the braking and suspension systems rounded out the major changes. Porsche introduced the 944 for MY 1982 to great anticipation. In addition to being slightly faster (despite having a poorer drag co-efficient than the 924), the 944 was better equipped and more refined than the 924's, it had better handling and stopping power and was more comfortable to drive. The factory-claimed 0-60 mph time of less than 9 seconds (8.3 seconds according to "Porsche the Ultimate Guide" By Scott Faragher) was actually rather modest. The factory-claimed top speed of 130 mph (210 km/h) was also pessimistic, Autocar having verified a top speed of 137 mph (220 km/h)[verification needed]. The car had nearly even front to rear weight distribution (50.7% front/49.3% rear) thanks to the rear transaxle balancing out the engine in the front.[2] This gave it very balanced, predictable handling at the limits of adhesion.
In mid-1985 the 944 underwent its first significant changes. These included : a new dash and door panels, embedded radio antenna, upgraded alternator (from 90 amp to 115 amp), increased oil sump capacity, new front and rear cast alloy control arms and semi-trailing arms, larger fuel tank, optional heated and powered seats, Porsche HiFi sound system, and revisions in the mounting of the transaxle to reduce noise and vibration. The "cookie cutter" style wheels used in the early 944s were upgraded to new "phone dial" style wheels. (Fuchs wheels remained an option.) 1985 model year cars incorporating these changes are sometimes referred to as "1985B", "85.5" or "1985½" cars.
For the 1987 model year, the 944 Motronic DME was updated, and newly incorporated anti-lock braking and air bags for increased safety. Because of the ABS system, the wheel offset changed to 52mm and Fuchs wheels were no longer an option.
In early 1989 before the release of the 944 S2, Porsche upgraded the 944 from the 2.5-liter engine to a 2.7-liter engine, bore 104 mm (4.1 in), stroke 78.9 mm (3.1 in), with a rated 162 hp (121 kW) (versus 158 hp (118 kW) for the 1988 2.5-liter engine) and a significant increase in torque. In addition to the increase in displacement, the new motor featured a siamesed-cylinder block design and a different cylinder head which incorporated larger valves.
For the 1986 model year Porsche introduced the 944 Turbo, known internally as the 951. This had a turbocharged and intercooled version of the standard car's engine that produced 220 hp (164 kW) (217 hp (162 kW) in the US) at 6000 rpm. The turbo was the world's first car using a ceramic port liner to retain exhaust gas temperature and new forged pistons. The Turbo also featured several other changes, such as improved aerodynamics, a strengthened gearbox with a different final drive ratio, standard external oil coolers for both the engine and transmission, standard 16 inch wheels (optional forged Fuchs wheels), and a slightly stiffer suspension (Progressive springs) to handle the extra weight. Major engine component revisions, more than thirty in all, were made to the 951 to compensate for increased internal loads and heat.
Changes occurred for the 1987 model year. On the interior, the 1987 944 Turbo became the first production car in the world to be equipped with driver and passenger side air bags as standard equipment. A low oil level light was added to the dash as well as a 180 mph speedometer as opposed to the 170 mph speedometer on the 1986 model Turbos. Also included is the deletion of the transmission oil cooler, and a change in suspension control arms in order to reduce the car's scrub radius. The engine remained the same M44/51 power-plant as in the 1986 model.
In 1988, Porsche introduced the Turbo S (SE in the UK). The 944 Turbo S had a more powerful engine (designation number M44/52) with 250 hp (186 kW) and 250 lb·ft (340 N·m) torque (standard 944 Turbo 217 hp (162 kW) and 243 lb·ft (329 N·m)). This higher output was achieved by using a larger K26-8 turbine housing and revised engine mapping which allowed maintaining maximum boost until 5800 rpm as compared to the standard 944 Turbo the boost would decrease from 1.75 bar at 3000 rpm to 1.52 bar at 5800 rpm. In June 1988, Car and Driver tested the 944 Turbo S and achieved a 0-60 mph time of 5.5 seconds and a quarter-mile time of 13.9 seconds at 101 mph (163 km/h). Top speed was factory rated at 162 mph (261 km/h).
The 944 Turbo S's suspension was the then state-of-the-art "M030" option consisting of Koni adjustable shocks front and rear, with ride height adjusting threaded collars on the front struts, progressive rate springs, larger hollow rear anti-roll/torsion bars, harder durometer suspension bushings throughout, larger 26.8 mm (1.1 in) hollow anti-roll/torsion bars at the front, and chassis stiffening brackets in the front frame rails. The air conditioning dryer lines are routed differently to clear the front frame brace on the driver's side. The 944 Turbo S wheels, known as the Club Sport design, were 16-inch forged and flat-dished, similar to the Design 90 wheel. Wheel widths were 7 inches (178 mm) in the front, and 9 inches (229 mm) in the rear with 52mm offset; sizes of the Z-rated tires were 225/50 in the front and 245/45 in the rear. The front and rear fender edges were rolled to accommodate the larger wheels. The manual transmission (case code designation: AOR) featured an higher friction clutch disc setup, and an external cooler, and also featured a limited slip differential with a 40% lockup setting. The Turbo S front brakes were borrowed from the Porsche 928 S4, with larger 4-piston fixed calipers and 12" inch discs; rear brakes remained the same as a standard Turbo. ABS also came standard.
The 944 Turbo S interior featured full power seats for both driver and passenger, where the majority of the factory-built Turbo S models sported a "Burgundy plaid" (Silver Rose edition) but other interior/exterior colors were available. A 10-speaker sound system and equalizer + amp was a common option.
In 1989 and later production, the 'S' designation was dropped from the 944 Turbo S, and all 944 Turbos featured the M44/52 package as standard.
For the 1987 model year, the 944S "Super" was introduced. The 944S featured a high performance normally aspirated, dual-overhead-cam 16-valve 192 PS (141 kW; 189 hp) version of the 2.5 litre engine (M44/40) featuring an self-adjusting timing belt tensioner. This marked the first use of four-valve-per-cylinder heads and DOHC in the 944 series, derived from the 928S4 featuring a redesigned camshaft drive, a magnesium intake tract/passages, magnesium valve cover, larger capacity oil sump and revised exhaust system. The alternator capacity was 115 amps. The wheel bearings were also strengthened and the brake servo action was made more powerful. Floating 944 calipers were standard, but the rear wheel brake circuit pressure regulator from the 944 turbo was used. Discrete '16 Ventlier' script badges were added on the sides in front of the body protection mouldings. Performance was quoted as 0 – 100 km/h (62 mph) in 7.2 seconds and a 232 km/h (144 mph) top speed. It also featured an improved programmed Bosch Digital Motronic Computer/DME with dual knock sensors for improved fuel performance for the higher 10.9:1 compression ratio cylinder head. Like the 944 Turbo, the 944S received progressive springs for greater handling, revised transmission and gearing to better suit the 2.5-litre DOHC higher 6800 rpm rev limit. A Club Sport touring package was available. Dual air bags, limited-slip differential and ABS were optional on the 944S as was the lightweight 16 inch CS/Sport Fuch forged alloy wheels. This car was raced in Canada, Europe and in the USA IMSA Firehawk Cup Series. Production was limited to two years; 1987 and 1988 only. It was superseded in 1989 by the 'S2' 944 edition.
In 1989 the 944S2 was introduced, powered by a 211 PS (155 kW; 208 hp) normally aspirated, dual-overhead-cam 16-valve 3.0L version of the 944S engine. With a bore of 104 mm (4.1 in) and a stroke of 88 mm (3.5 in), it was the largest production 4-cylinder engine of its time.[citation needed] The 944S2 also received a revised transmission and gearing to better suit the 3.0-liter M44/41 powerplant. The 944S2 had the same rounded nose and a rear valance found on the Turbo model. This was the first example of the use of an integrated front bumper, where the fender and hood profiles would merge smoothly with the bumper, a design feature that has only now seen widespread adoption on the 1990 onward production cars. Performance was quoted as 0-60 mph in 6.5 seconds (0–100 km/h 6.8 s), with a top speed of 240 km/h (150 mph) via manual transmission. In 1990 Porsche released the 944 S2 Cabriolet, a first for the 944 line which featured the cabriolet body built by ASC-American Sunroof Company at Weinsberg Germany. Porsche produced units for all markets including right-hand drive for the United Kingdom, Australia and South Africa.
In early 1990, Porsche engineers began working on what they had intended to be the third evolution of the 944, the S3. As they progressed with the development process, they realized that so many parts were being changed that they had produced an almost entirely new vehicle. Porsche consequently shifted development from the 944 S to the car that would replace the 944 entirely, the 968. The 944's final year of production was 1991; in 1992 the 968 debuted. The 968 was sold alongside the 928 through 1995, when both water-cooled front engine models were discontinued.
Specifications.
Bodywork. Length/width/height/wheelbase – cm (in) : 429/174/128/240 (168.9/68.3/50.2/94.5); weight : 1312 kg (2896 lb).
Mechanics. Front straight-four 2990 cc (182 ci), 16 valves, injection, manual 5-speed gearbox, rear-wheel drive. Maximum power : 209 bhp at 6200 rpm; torque : 285 Nm at 4000 rpm. Top speed : 245 km/h (152 mph); 0 – 60 mph in 6.6 sec.