Porsche 924

The 924 originated as a contract design by Porsche for Volkswagen, based mainly on readily available parts from the VW parts bin. The car was to be the VW Type 477, also known by the code name EA435. However, VW chose to cancel plans late in the project for financial reasons. Porsche then bought the rights to the design for $60 million ($10 million less than the cost of development) and produced the car, having VW assemble the cars at its Audi plant in Neckarsulm. Initial configuration was a 2.0L inline-4 SOHC engine producing 125hp in the ROW (Rest of World) configuration, 95hp in the US, mated to a 4-speed transmission, with solid front disc and rear drum brakes. Porsche then proceeded through a series of upgrades to improve the performance of the car to meet the public's expectations of Porsche performance. Upgrades involved better brakes (vented discs front and rear), optional sport suspension (including springs, torsion bars, swaybars, shocks and struts), 5-speed transmissions, and more power for the engine. Comfort and convenience upgrades included the addition of AC, power windows, power mirrors, better stereo, optional 3-speed automatic transmission, and the like.

Other steps were taken by Porsche to try to improve the car's appeal in the market, starting with special editions such as the Martini Edition (also known as the Championship Edition, in 1977), the Limited Edition (1978), and the Sebring edition (1979). Trying to take this effort further, Porsche worked with a few major American dealerships starting in 1979 to enter and conquer the SCCA's D-Production arena with the D-Prod Kit Cars, known internally as the 933 (the internal Porsche project number). 16 of these were made. Most are still around, but few are still in D-Prod form, as the class was dropped in the 80's. The majority have been upgraded to GT3 specs for SCCA racing, or GT5 in Porsche Club Racing.

The real boost in performance the 924 needed was achieved with the release of the 924 Turbo, also known as the 931, in late 1979. Compression was reduced slightly from the 924 to handle the boost, and a new head was implemented with better flow characteristics. Boost levels were moderate, 8-10psi. The engine was fitted with an oil cooler for durability. The 931 came with a 5-speed trans from the start, but had the early-style disc/drum brakes. It became clear that the increased performance of the 931 needed the better, later, optional 4-wheel vented disc brakes. Later versions of the 931 received improved digital ignition systems. 931's are most easily identifiable by the NACA duct in the hood on the right hand side, the slotted vents on the front nose on the badge panel below the Porsche badge.

In 1981 the 924 Carrera GT was released, the hot-rodded 931, also known as the 937. Cosmetically, it foreshadowed the 944, with a wide front end to cover the wider track, but the rear width was strictly increased through the use of small add-on flares, as seen currently on the 911 GT2 cars. The extra bodywork was all plastic, not fiberglass. The better brakes were standard, but with slightly different brake circuitry due to the different suspension geometry. 16" Fuchs rims and upgraded suspension and brakes were standard. The engine made substantially more power than the 931 thanks to an intercooler, higher boost, and lower compression. The intercooler was mounted integral to the charge tube going from the turbo to the throttle body, right over the cam cover, to minimize turbo lag. However, getting airflow to this location was difficult, and resulted in the scoop on the hood over the cam cover. Only 406 of these were made, and none officially imported to the US, though a handful made it in through private importers (grey-market).

Later on the Carrera GTS and GTR were released. These were not referred to by distinct model numbers, as they were developed from the 937 Carrera GT, and so are also considered 937's. They were, by contrast with the other models, built at Porsche in Zuffenhausen. The GTS had an intercooler in the nose, as later reused in the 944 Turbo, with fixed headlights behind plexiglass covers forced by removal of the headlight linkage to accommodate the intercooler ducting. Weight was lowered and power improved, but the car was still street-legal, at least in Europe. 59 GTS's were made, with 15 in Club Sport configuration - further weight-reductions, rollcage, etc. The GTR was a pure racecar, developed for the endurance races of LeMans, Sebring, and the like, making 375bhp and beyond, and weighing even less. Every detail of the cars were heavily modified for racing, especially the suspension, with plenty of details for endurance racing, like air jacks, dry-break fuel cell refueling, etc. The roll cages were particularly neat, being constructed of welded alloy, well gusseted and bolting into the car's body at 14 points. A matching strut tower brace added further stiffening in front of the firewall. The intercooler for the GTR was much larger besides than the GTS, but also located in the nose of the car. Only 18 GTR's were constructed.

Porsche 944

The 944 was the direct descendant of the 924 Carrera series and ultimately the earlier 924/931. Beginning in 1979 and the following two years Porsche began developing racing hybrids based on the 924 which later lead to the 944. In 1979/80 Porsche built 406 examples of the 924 Carrera GT. In the following two years, Zuffenhausen continued on to develop several competition versions of the 924 culminating in 1982 with the 924 Carrera GTS (of which 5 were built up as Club Sport models and sold to private owners,) and the limited competition 924 Carrera GTR. When looking at the Carrera GTS Club Sport, one can immediately see the immanent arrival of the 944.

In order to improve build quality, over the 924 production done at Audi's facility in Neckarsulm, production/assembly of the 944 was done in Zuffenhausen. The power plant was literally derived from half of the 928's V8. At 2479 cc (2.5 liters) the engine was large by four cylinder standards of the day. The engine was a modern design with high compression and a broad power band. The initial power plant was rated at 163 hp (ROW) and 150 hp for the U.S.
The 944 was originally announced to the world at the September, 1981 Frankfurt auto show with the U.S. introduction one year later. Upon its introduction the interior of the 944 remained much the same as the 924 while the rear suspension, although improved, retained the VW-derived architecture.

In addition to a change in the front suspension control arms, the rear suspension would change with the major revision of the 944 that occurred mid year in 1985. Often times, owners will refer to there 944 as an 85.5, designating the completely redesigned interior and other improvements to the base 944 including; new heater, air conditioning, minor revisions to the bodywork including a flush mounted windscreen, new cats aluminum front A-arms and rear trailing arms suspension components. Although changes where made to the engine, Porsche did not announce any changes to the factory performance specifications. Practical comparison of this watershed model change and it's predecessors indicates performance gains did result however.

At the end of 1985, Porsche announced the 944 Turbo (factory model designation 951) which arrived in the U.S. as a 1986 model. Performance of the 951 was a reminder of the 944's legacy, even in it's toned down production form. Aside from the turbo charged power plant generating 217 hp with 243 ft/lbs of torque, the 951 had other major enhancements over it's normally aspirated brother. Specifically the 951 included aerodynamic polyurethane front bumper/spoiler with new air intakes serving the turbo's intercooler mounted between the headlights under the front panel. Under body panels where added to cleanup air flow beneath the car. This extended to the distinctive air diffuser mounted under the rear of the car to cleanup exiting airflow past the rear end. As well, the 951 received Bembo 4 piston calipers to bring the car to a stop as well as special forged alloy wheels. The suspension received stiffer components to round out the comprehensive performance upgrades. The 951 also has the distinction of being the first sports car to offer both driver-side and passenger-side airbags. Porsche also produced 198 versions of the 944 Turbo as Cup racing cars.

The 944S arrived as a 1987 model year addition with a redesigned 16 valve dual overhead cam engine producing 190 hp. In addition to the increased number of valves and cams, the 944S came with an improved Digital Motor Electronics (DME) system with knock-sensing regulation capabilities. Also included on the base 944, the 944S benefited from the new timing belt tensioner which was implemented for the 1987 model year. As well, the 944S received the Bembo brake calipers with optional ABS. The initial 944S shared the base models bodywork until 1990.

Porsche revisited the 951 and in 1988 introduced the 944 Turbo S with total model year production of 718. This performance version of the already impressive 944 Turbo received many significant improvements including: bigger Bempo brakes, ABS, firmer springs and torsion bars, stiffer Koni low-pressure gas adjustable shock absorbers, a thicker front sway bar, and firmer suspension bushings. The following year, Porsche dropped the "S" designation and the standard 944 Turbo was infact the "S" form factor, building 1385 for 1989. This was to be the last year the U.S. market would have access to the 944 Turbo.

In 1990 Porsche releases the 944 Series 2, designated 944 S2. The S2 was an extensive revision of the 944S which now included the aerodynamic bodywork of the 951. The previous three engines available were replaced by the 3.0 liter's 16 valve engine and a big turbo 2.5 liter 944 Turbo (sold in Europe). As well, a soft-top version of the 944 was introduced, the 944 S2 Cabriolet. The new cabriolet was produced jointly by Porsche and the German division of the American Sunroof Corporation.

Porsche 968

In the fall of 1991, Zuffenhausen announced the Series 3 944, model designation 968. There was a brief period where what we now know as the 968 was to be designated the 944 S3 but in order to boost slumping sales, the model was marketed under it's factory designation and technically represented the final refined version of the 944 family line. In addition to further tuning of the 3 liter motor seen in the S2, the 968 debuted with circular headlamps, new nose and rear end. The interior remained virtually unchanged from the past several years. In addition output of the 3 liter was increased to 240 hp, resulting in the most powerful normally aspirated production 4 cylinder available. Performance was primarily gained through the use of a Variocam, a camshaft chain drive with an adjustable tensioned to retard intake valve actuation up to 7.5 degrees. Along with the 29 hp increase, torque was also increased from 207 lbft to 225 lbft. The engine also now included piston oil spray cooling from squirters similar to the 911. Managing the power transfer to the rear wheels was a six speed gearbox (offered as either a ZF or Torsen limited slip differential,) or an optional 4 speed Tiptronic. The ZF LSD was to be deleted the following year in 1993 with the Torsen version as the only one offered (option code M220).

As a final testament reaching all the way back to the 924 Carrera Club Sport, the 968 Club Sport version appeared in 1993. The 968 CS included one inch reduction in ride height, stiffened springs and dampers, fully adjustable suspension, and reduce weight. As with past Porsche Club Sport models, weight reduction was obtained through deleting luxuries like; air conditioning, power windows, leather seats, stereo, and sound insulation from the passenger compartment. In actuality a stripped down high performance version of the 968 Coupe, Porsche priced the 968 CS (available only in Europe,) under $60,000, which was considerably cheaper than production super cars of the time. The 968 CS represented the pinnacle of performance and handling for the normally aspirated 944/968.

That being said, Porsche had one final parting pass at the 968 which resulted in the ultimate performance incantation, the 968 Turbo S. The Turbo S was a rare model only offered as limited production (15 examples total ) available in Europe. The water cooled KKK turbocharger produced 305 hp (@5,400 rpm) and 369 lb-ft of torque (@3,000 rpm). Based on the 968 CS, the Turbo S rivaled even the 911 Turbo of that year. In 1995, with development of the Boxster well underway and set to debut in 1996, Porsche discontinued the 968 bringing to a close the most successful line of Porsche outside of the 911.

In that final year Porsche produced and campaigned a competition version of the 968 Turbo S designated the 968 Turbo RS. Blisteringly fast with the by now the respected handling attributes of the 944 S2 suspension architecture, it was a champion from the perspective of performance with some 377 hp. This would be the final farewell to arguably one of the most underrated Porsche production lines ever.