The first official appearance of the 924 took place in November 1975 (as a press launch rather than a motorshow appearance) at the harbour at La Grande Motte, Camargue in the south of France. The model was a success and not only helped to take Porsche out of financial ruin, but created the revenue stream needed to continue building and developing the 911. The 924 was replaced by the 944 in 1983 in the U.S. market, but continued to be produced until 1985 for other markets.
For the 1986 to 1988 model years the car acquired the powerplant from the 944 model and became the Porsche 924S.
The 924 was originally intended to be Volkswagen's flagship coupé sports car and was dubbed "Project 425" during its development. At the time, Volkswagen lacked an internal research and design division, and Porsche was doing the bulk of the company's development work, per a deal that went back to the 1950s; in keeping with this history, Porsche was contracted to develop a new sporting vehicle with the caveat that this vehicle must work with an existing VW/Audi I4 engine. Porsche chose to stick a rear wheel drive layout and a rear-mounted transaxle for the design to help provide 48/52 front/rear weight distribution; this slight rear weight bias aided both traction and brake balance.
The 1973 oil crisis, a series of automobile-related regulatory changes enacted during the 1970s and a change of directors at Volkswagen made the case for a Volkswagen sports car less striking and the 425 project was put on hold. After serious deliberation at VW, the project was scrapped entirely after a decision was made to move forward with the cheaper, more practical, Golf-based Scirocco model instead. Porsche, which needed a model to replace the 914, made a deal with Volkswagen leadership to buy the design back.
The deal specified that the car would be built at the ex-NSU factory in Neckarsulm located north of the Porsche headquarters in Stuttgart, the Volkswagen employees would do the actual production line work and that Porsche would own the design. It became one of Porsche's best-selling models, and the relative cheapness of building the car made it both profitable and fairly easy for Porsche to finance.
The original design used an Audi-sourced four-speed manual transmission for the 924 mated to VW's EA831 2.0 L I4 engine, subsequently used in the Audi 100 and the Volkswagen LT van (common belief is that the engine originated in the LT van, but it first appeared in the Audi car), as well as in the AMC Gremlin, Concord, and Spirit. The engine used Bosch K-Jetronic fuel injection, producing 95 horsepower (71 kW) in North American trim. This was brought up to 110 horsepower (82 kW) in mid-1977 with the introduction of a catalytic converter, which reduced the need for power-robbing smog equipment. The four-speed manual was the only transmission available for the initial 1976 model. An Audi three-speed automatic was offered starting with the 1977.5 model.
European models, which did not require any emissions equipment, made 125 hp (93 kW). They also differed visually from the US spec model by not having the US cars' low-speed impact bumpers and the round reflectors and side-marker lamps on each end of the body.
A five-speed transmission, available in normally aspirated cars (type 016) starting in 1979 and standard on all turbos (type g31), was a dog-leg shift pattern Porsche unit, with first gear below reverse on the left side. This was robust, but expensive due to some 915 internal parts, and was replaced for 1980 with a normal H-pattern Audi five-speed on all non-turbo cars. The brakes were solid discs at the front and drums at the rear. The car was criticized in Car and Driver magazine for this braking arrangement, which was viewed as a step backward from the 914's standard four-wheel disc brakes. However, four-wheel disc brakes, five stud hubs and alloys from the 924 Turbo were available on the base 924 as an "S" package starting with the 1980 model year. Also, standard brakes could be optioned on the turbo as a cost saving measure.
The overall styling was created by Dutchman Harm Lagaay, a member of the Porsche styling team, with the hidden headlights, sloping bonnet line and grille-less nose giving the car its popular wedge shape. The car went on sale in the USA in July 1976 as a 1977 model with a base price of $9,395. Porsche made small improvements to the 924 each model year between 1977 and 1985, but nothing major was changed on non-turbo cars. Turbo charged variants received many different, non-VW sourced parts, throughout the drive train, and when optioned with the m471 disc brake package and forged 16" wheels, the car was twice as expensive as a standard model.
J. Pasha, writing in Excellence magazine, at the time, described the 924 as "the best handling Porsche in stock form".
While the car was praised for its styling, handling, fuel economy, and reliability, it was harshly written up in the automotive press for its very poor performance, especially in its US spec cars. With only 95-110 hp, rapid acceleration was simply not an option, but the Porsche name carried with it higher expectations. When the 924 turbo models came out, Car and Driver magazine proclaimed the car "Fast...at Last!" The later 924S had performance on par with the turbo, but at much improved reliability, and less cost. The 81 and 82 Turbos and the associated special variants are garnering interest in collector circles; and while many still exist, excellent examples of the cars are quite scarce as of 2009.
Porsche executives soon recognised the need for a higher-performance version of the 924 that could bridge the gap between the basic 924 and the 911s. Having already found the benefits of turbochargers on several race cars and the 1975 911 Turbo, Porsche chose to use this technology for the 924, eventually introducing the 924 Turbo as a 1978 model.
Porsche started with the same Audi-sourced 2.0 L I4, designed an all new cylinder head (which was hand assembled at Stuttgart), dropped the compression to 7.5:1 and engineered a KKK K-26 turbocharger for it. With 10 psi (69 kPa) boost, output increased to 170 horsepower (130 kW). The 924 Turbo engine assembly weighed about 65 lb (29 kg) more, so front spring rates and anti-roll bars were revised. Weight distribution was now 49/51 compared to the original 924 figure of 48/52 front to rear.
In order to help make the car more functional, as well as to distinguish it from the naturally aspirated version, Porsche added a NACA duct in the hood and air intakes in the badge panel in the nose, 15-inch spoke-style alloy wheels, four-wheel disc brakes with 5 stud hubs and a five-speed transmission. Forged 16" flat wheels of the style used on the 928 were optional, but fitment specification was that of the 911 which the 924 shared wheel offsets with. Internally, Porsche called it 931 (left hand drive) and 932 (right hand drive), much like the 911 Carrera Turbo, which had been "Type 930". These designations are commonly used by 924 aficionados.
The turbocharged engine allowed the 924's performance to come surprisingly close to that of the 911 SC (180 bhp), thanks in part to a lighter curb weight, but it also brought reliability problems. This was in part due to the fact that the general public did not know how to operate, or care for, what is by today's standards a primitive turbo setup.
A turbocharger cooled only by engine oil lead to short component life and turbo-related seal and seat problems. To fix the problems, Porsche released a revised 924 Turbo series 2 (although badging still read 924 Turbo) in 1979. By using a smaller turbocharger running at increased boost, slightly higher compression of 8:1 and an improved fuel injection system with DITC ignition triggered by the flywheel, reliability improved and power rose to 177 horsepower (132 kW; 179 PS).
After a successful sales run of both naturally aspirated and turbo models, in 1980 Porsche surprised everyone and release the 924 Carrera GT, making clear their intention to enter the 924 in competition.
By adding an intercooler, increasing compression to 8.5:1 as well as various other little changes, Porsche was able to develop the 924 Turbo into the race car they had wanted, dubbing it the 924 Carrera GT.
In order to comply with the homologation regulations, the 924 Carrera GT and later 924 Carrera GTS were offered as road cars as well, producing 210 and 245 hp (157 and 183 kW) respectively. Clubsport versions of the GTS were also available with 280 hp (209 kW; 284 PS), a factory included Matter rollcage and race seats. 924 Carrera GT variations were known by model numbers 937 (left hand drive) and 938 (right hand drive).
The ultimate development of the 924 in its race trim was the 924 Carrera GTR race car, which produced 375 horsepower (280 kW; 380 PS) from a highly modified version of the 2.0 L I4 used in all 924s. In 1980 Porsche entered three 924 GTRs at the 24hrs of Le Mans, which went on to finish 6th, 12th and 13th overall. In 1981 Porsche entered a 924 Carrera GTP which used a highly modified 2.5 liter I4, the same capacity as the forthcoming 944. This engine sported 4 valves per cylinder and a single turbocharger to produce 420 hp (313 kW; 426 PS). This last variant managed a 7th place overall finish and spent the least time out of any other car in the pits.
Production of the 924 Turbo ceased in 1982 except for the Italian market which lasted until 1984. This is due to the restrictions on engines larger than 2 liters, putting the 2.5 liter 944 into a much higher tax category.
.In 1984 VW decided to stop manufacturing the engine blocks used in the 2.0 924, leaving Porsche with a predicament. The 924 was considerably cheaper than its 944 stablemate, and dropping the model left Porsche without an affordable entry-level option. The decision was made to equip the narrower bodied 924 with a slightly detuned version of the 944's 163 bhp 2.5 litre straight four, upgrading the suspension but retaining the 924's early interior. The result was 1986's 150 bhp 924S. Porsche also decided to re-introduce the 924 to the American market with an initial price tag of under $20,000.
1987 saw Porsche release the limited edition 924S Le Mans. Available only in Alpine White or Black, it had upgraded suspension and cosmetically upgraded interior and exterior. In Le Mans spec, the S' 2.5 litre engine produced an additional 10 bhp (7 kW; 10 PS), taking the total to 160. The Le Mans also came with an electric sunroof as standard (normally an option). A total of 980 924S Le Mans were manufactured during the 1987 model year; 813 cars in black (the only colour available for the US market) and 167 white cars.
In 1988, the 924S' final year of production, power increased to 160 bhp (119 kW; 162 PS) matching that of the previous year's Le Mans spec cars and the base model 944 (itself detuned by 3 bhp (2 kW; 3 PS) for 1988). This was achieved using different pistons which raised the S' compression ratio from 9.7:1 to 10.2:1, the knock-on effect being an increase in the octane rating, up from 91 RON to 95. This made the 924S slightly faster than the base 944 due to its lighter weight and more aerodynamic body.
In 1988 The Porsche 924s-SE was introduced, only 500 cars were produced and sent to the United States.
With unfavourable exchange rates in the late 1980s, Porsche decided to focus its efforts on its more upmarket models, dropping the 924S for 1989 and the base 944 later that same year.
924S Special models
88 924S SE and LeMans, aka Club Sport editions.
Only 980 Club Sport option cars were built in total.
500 units for USA. Option code was M756. LSD, Sunroof rear rock guard were optional, 15x6 phone dials, manual windows and locks, standard M030 suspension. Came with a SE medallion.
250 GER 200 black and 50 white cars
230 ROW 113 black and 117 white
ROW Paint finishes and interiors were only offered in two colour choices - Alpine White with Ochre/Grey detailing or Black with Turquoise detailing.
US was black only with optional SE Edition decal.
ROW The exterior side stripes were broken by scripted ‘LE Mans’ logos on the lower part of the door, while the rims of the holes in each wheel were in the appropriate Ochre or Turquoise. Inside, the cars featured sports seats.
ROW Upholstery was grey/ochre striped flannel cloth with ochre piping for Alpine White cars, or grey/turquoise with turquoise piping for Black cars.
US Interior was gray with maroon pinstriping, and maroon carpeting (upholstery is weak fabric and does not hold up to sun).
All the cars had the 360 mm (14 in) steering wheel, with, as a final flourish, the cloth door panels colour-coded to match the detail colours. All cars came with a 160 BHP engine plus an electric tilt/removable sunroof fitted as standard. It was also lowered 10 mm (0.39 in) at the front and 15 mm (0.59 in) at the rear, and fitted with stiffer springs and gas-filled shock absorbers all round. It was further given sport anti-roll bars with diameters of 21.5 mm (0.85 in) at the front but 20 mm (0.79 in), rather than 14 mm (0.55 in), at the rear. Wheels were ‘telephone dial’ cast alloy 6J x 15 at the front and 7J x 15 (at the rear).
The Porsche 924 and motorsport
The 924 has its own racing series in the UK run by the BRSCC and Porsche Racing Drivers Association. The Porsche 924 Championship was started in 1992 by Jeff May who was championship coordinator until his death on 10 November 2003. May was also one of the founding members of Porsche Club Great Britain. In the United States, the 924S is also eligible to race in the 944-Spec racing class.
Internationally, the 924 was raced by privateers in several major motor races, including the 24 Hours of Le Mans and 24 Hours of Daytona. Factory backed efforts were sent to the 1980 edition of Le Mans, the best of the trio ending the race in sixth place after a trouble free race. In 1984 a Porsche 924 Carrera GTR would be driven by ex-Formula One racer Innes Ireland at the 24 Hours of Daytona, the last race for the Brit, although the car retired mid-race.