964 vs 3.2 Carrera
The 964 was a technical leap over the 3.2 Carrera, but how and why was this once controversial new model introduced? Total 911 assesses the Neunelfer’s crucial evolution of 30 years ago
In our build-up to celebrating 30 years of the 964, find out how the car improved the 911 game
By 1984, as the latest 3.2 was appearing in the showrooms, the 911 was already a phenomenon: it had far exceeded the impressive 15-year life of the 356 and, thanks to the passion and insight of then-ceo Peter Schutz, showed no signs of flagging. No other mass-production car conceived in the 1960s survived into a third decade. In 1982 Ford had built the last Cortina, but that car had been rebodied no fewer than four times; only the primitive Land Rover could offer the visual continuity of the 911.
The Porsche remained both profitable and near the top of the performance league. In 1984 231bhp was respectable, and on the quieter roads of those times a driver could deploy such horsepower regularly in a way quite impossible for today’s
500bhp 911s. Indeed, to beat a 3.2 you needed an Italian exotic of the type that required a mechanic in the boot, and even then it would never sustain day-in day-out 120mph use on the Autobahn.
But if the 911 was still a selling proposition, the strength of the dollar during the early 1980s making Porsche an increasingly attractive proposition to Americans, this masked the fact that it was dated. It had no power steering, a ride quality not worthy of its price bracket, no auto transmission option and
Byzantine heating and ventilation systems. Australian journalist Peter Robinson said in 1978: “The 911 belongs to another era. It’s showing its age and not just around the edge, so let’s put it out to pasture with the other thoroughbreds before it breaks down and has to be destroyed in front of its adoring public.”
Such antipodean directness was too much for Porsche, and Robinson later revealed that it was 11 years before Porsche would let him near another press car. Nevertheless, there were rumblings within Porsche too. Styling director Tony Lapine was a wellknown 911 dissident, but Peter Falk was also critical. A man steeped in 911 development, and who before retirement produced the famous Lastenheft which sought to redefine the fundamental characteristics a new 911 should have, Falk represented the very essence of 911 integrity and tradition. After 20 years he wanted to see improvements, such as dispensing with the archaic torsion bars.
Falk’s voice did not go unheard. In April 1984 the board authorised development of the next 911,
Typ 964. This would be the 911’s first step to making up lost ground. In fact, when it was revealed in 1988, the 964 looked remarkably like its predecessor.
The board had stipulated that nothing was to be changed above the level of the axles. This had vastly restricted the designers, but Dick Soderberg’s skilful melding of the impact bumpers into the bodywork was widely praised, and the smooth-surfaced, technical-looking ‘Design 90’ 16-inch wheels were much admired. All of a sudden the Fuchs appeared old-fashioned.
The 964 remit to the chassis engineers was just as challenging this time because of everything that had to be changed. The success of Ferdinand Piëch’s Audi Quattro had convinced Ferry Porsche and Helmuth Bott that a version of the 911 should have integral transmission. That meant abandoning torsion bar suspension and redesigning the 911’s underside to accept conventional springing, which at the front would also make room for power steering. Air suspension was also planned. In October 1986 Bott hinted in Auto Motor & Sport that the next 911 would be a very significant advance; evolutionary, but using 959 technology, and positioned more closely to the Porsche super car to make a “better 911”. For a car barely changed since its inception, such statements raised expectations.
To simplify production one floorpan was designed to cover both types, four- and two-wheel drive. The new suspension used struts at the front, as had the previous 911, but with lower wishbones and with adjustment of the steering axis to accommodate power steering, and a geometry suited to another advance, ABS brakes. At the rear, revised struts were configured so that toe-out of the inner wheel during cornering was eliminated, held in place by steel semitrailing arms designed with a degree of flexibility. Anti-roll bars were fitted, 20mm at the front and 21mm at the rear.
If cost put paid to the air suspension for which the 964 had really been designed, the model’s essential new development did go ahead. The allwheel-drive transmission was basically the same as that designed for the 1984 Dakar-winning 953: a fixed torque split of 31:69 front/rear differed from the 964’s weight distribution of 41:59 in an effort to reduce the natural understeering characteristic of the 4x4 transmission – an asset on desert sand, but which on dry tarmac detracted from the 911’s traditionally sporty handling. Engineer Walter Näher and veteran test driver Herbert Linge would cover many circuit miles in attempts to get this handling balance right. Behind the stylish new wheels were ventilated disc brakes, and their ABS sensors were linked to the transmission, intervening to transfer more torque to front or rear if loss of traction of one axle was discerned.
Considering the flat six, unlike chassis and styling, was to be carried over simply with appropriate power and torque increases, it’s surprising that it was the engine which caused the greatest head scratching at Weissach, ultimately delaying the launch of the 964 by well over a year. From the outset Bott was concerned that the revised shell and integral transmission, which added 200kg, would demand more power and torque. Another consideration was an engine which would operate worldwide without the need for detuned Us/japan versions. It would also have to be designed around the catalytic converter, scheduled to become mandatory in Europe in 1993.
Work had started as early as 1983. An early decision was twin-spark ignition, long a characteristic of Porsche racing engines, but entirely new for production. This made combustion more consistent and created a more stable idle, allowing the Bosch Motronic to weaken the mixture to the benefit of economy during warm-up.
However, the real challenge was the lower hydrocarbon and NOX levels demanded by California. The production 3.2 produced only 207bhp in ‘detoxed’ form, and increasing output while keeping emissions in check was generating excessive cylinder head temperatures. There was no room to build four valves per cylinder, and a water-cooled head was too expensive and technically fraught. Using the 97mm bore of the Turbo to make a capacity of 3.3, bench testing achieved 235bhp, still short of the 240bhp Bott believed was essential. Draughting around the flat six was improved, a more efficient fan designed and the cylinder head gasket eliminated to improve heat flow.
Combined with revisions to the finning, an acceptable operating temperature of 255 degrees Celsius was attained. Now the engineers increased capacity again: a 100mm bore resulted in a 3,506cc displacement, but this demanded modifications to the crankcase halves and cylinder head to accommodate everything. At the same time Porsche and Bosch had to upgrade the Motronic, which did not have the chip power to cope with ignition timing at high rpm, invoking the knock (pinking) sensor and reducing acceleration.
Even the 3.6-litre engine caused Bott doubts, and the power output challenge was finally resolved when his engineers lengthened the stroke to 76.4mm (from 74.4mm), which made exactly 3,600cc. At last testing the engine showed a consistent 250 horsepower at 6,100rpm. Production engines would in fact average 255 to 258bhp at the time. Maximum torque at 310Nm was a substantial increase over the 3.2’s 264Nm. The 3.6 proved a fine engine, particularly in the 993, but its protracted development, including a new crankshaft, had been very expensive.
The first pictures of the new 911, the Carrera 4, were released in May 1988, and press cars became available in early autumn. Journalists appreciated Soderberg’s styling, and noted Porsche’s claimed Cd of 0.32, a remarkable figure for such a short car. In fact, aerodynamically the 964 was just as impressive as this figure suggests. Its neat retractable rear spoiler which eliminated lift was the visible part of an airsmoothing package which included panelling the underside with careful air ducting to cool the engine and prevent frontal lift.
The scribes also viewed favourably the conservative revisions to the cockpit with (at last) rationalised heating and ventilation controls, and they also liked the short gear lever, a gain directly from the 959. On the road, testers approved of the 911’s new power assistance, which took some of the kickback out of the 911’s steering.
Michael Cotton’s comments were typical: “The steering no longer feels alive to every contour of the road and there will always be those who say it has lost its particular charm, but for each of those,
a dozen will welcome its modernity and taming of its vices.” There are parallels with the debate a quarter of a century later about the merits of the 911’s electrically assisted rack.
Nevertheless, the feeling was that despite the company’s efforts, the default position of the Carrera 4 was understeer, and there was relief among Porsche fans a year later when the Carrera 2 appeared. The magazines thought the C2 cornered more eagerly than ever, and its accurate assisted steering fatigued the driver less than the 3.2.
Indeed, driving the 964 and the 3.2 today it is not only the later car’s more abundant midrange torque, but the linearity of its steering which differentiate them. The unpowered 3.2 rack weights up as corners tighten, making it altogether the more demanding. The 964’s shorter gearshift is much more intuitive as well. Otherwise road behaviour and refinement levels are remarkably similar, both 3.2 and 964 Carreras offering a distinctly vintage Porsche 911 driving experience from their air-cooled motors.
The 964 Carrera 4 maintained Porsche’s preeminence in the performance stakes with 0-62 mph in 5.5 seconds and a top speed of 161mph according to Auto Motor & Sport, recording 5.5 and 164mph for the C2; a Zf-developed four-speed automatic was also available for the Carrera 2, and apart from initial stepoff it offered virtually identical acceleration figures.
The 964’s best year with over 20,000 made was 1990, by which time the 3.2 was out of production. Sales subsequently declined, affected in particular by the collapse of Porsche’s US market. The
Cabriolet remained popular, but by 1992 – when a mere 9,747 964s of all types were sold – interest in the Targa had all but dried up. A Speedster version hit the market at the wrong time, selling only 800 when a run of 3,000 had been hoped for, and the revised Porsche Cup race series, which from 1990 featured 911s rather than 944Ts, served only to reinforce Porsche’s reputation among existing fans.
In a weak market the 911, even the updated 964, lacked wider appeal. It was still raucous, the ride was affected by road noise and harshness transmitted through the rear suspension; overall it lacked the refinement expected of a £50,000+ car.
The 964 was a bold but incomplete first step to renew a model which had served an amazing 25 years unchanged. The 911 story of the next quarter century would be one of rapid developmental leaps, but it’s a model which just as amazingly would remain instantly recognisable as a 911 a further 25 years later: a unique achievement.
See how the 964 story developed in an upcoming issue of T911 celebrating 30 years of the 964.
thanks
Thanks to Porsche Club GB R27 members Mark Sloane and David Donnell for supplying the cars in our feature.
“An early decision was twin-spark ignition, long a characteristic of racing”