Porsche 965 prototype: 911 that broke all taboos

Super sports car, technology carrier, top model, 959 successor: those are quite ambitious goals, even for a 911 Turbo. The fact that the development of the Porsche 965 was stopped and that it eventually ended up in the cabinet of curiosities of the manufacturer from Zuffenhausen in 1992, does not mean that it did not play an important role in the 911 evolution process. We now know that this model forms the missing link between the traditional air-cooled models and the water-cooled era. Honor where credit is due. Of the 16 prototypes that were built, only the one in front of us remains: number L7. The matte black, practical and coarsely finished car does not even have a Porsche emblem. Instead, there’s a meaningless sticker on the nose. The dashboard and the rest of the interior also look improvised and tired. It is difficult to properly describe the design. The Porsche 965 has some similarities with the 959 (such as the wide rear with fixed spoiler) and we see many 968 features. Beautiful is different, but this is no more than a mule for testing new technology. Underneath the heavy tailgate, which extends over the entire rear, is an Audi V8, which has actually been pressed in and is surrounded by all kinds of hand-crafted components. It is the culmination and at the same time the end of a development process that started in the early 1980s. Already at the first ‘Produktplanungsgespräch’ in September 1982 there was discussion about twin turbos, four-wheel drive and four camshafts. The development target: 374 hp from a displacement of 3.3 liters. The engineers of the engine department point out that four-valve technology can only be realized with water-cooled cylinder heads. The development of the new engine will therefore be quite a challenge. In April 1984 the concept was ready on paper, the development of the new über-Elfer was merged with that of the 964 model series.

The intention is that the Porsche 965 will replace the expensive and complex 959, but will also continue to build on this model in terms of technology. In addition to biturbo technology and four-wheel drive, an optional dual-clutch transmission, standard 928 tire pressure monitor, airbags for the driver and front passenger, an on-board computer and air suspension are planned. For the 1990 model year, the newcomer should be on the market as a Coupé, Targa and Cabrio. In October 1985, the first major decision was made that will keep the new top-of-the-line model closer to the regular 911 than the 959 ever did. The 964 and 965 will have identical bodies. A product name is also chosen: the 965 should be marketed as a 969. The sales department assumes a sales volume of 2,500 units per year, with a price of approximately 180,000 D-marks on the domestic market. Let’s move the clock forward to 1988, a crucial year for the 965. The evolution process starts to lead to the necessary problems just before the market introduction. More and more issues are emerging that give engineers the necessary sleepless nights.

It starts with the engine. With a catalytic converter, the air-cooled biturbo with a displacement of 3.4 liters should deliver a power of 350 hp, which is enough for a top speed of 290 km/h. However, the temperatures of the cylinders and cylinder heads are too high and the technicians are unable to solve the problem. The head of the development department, Hellmuth Bott, will come up with an alternative in August: the Indy V8 engine with four valves per cylinder and DOHC technology, proven in American motorsport. If two cylinders are removed from this engine, it could power the 964 with a low turbo pressure and the 965 with maximum turbo pressure. Even a further developed version of the 959 engine is suddenly possible again. Just like a fully water-cooled boxer engine with the lower block of the 964 and the further developed cylinder heads of the 965. In other words: after six years of development, no suitable engine for the super-Turbo has yet been found.

On November 14, 1988, a long list of possible alternatives that could serve as a power source for the 965 is drawn up. These include the Indy V8-derived engine with 400 hp, which could go into production for model year 1995 in a naturally aspirated version and as a turbo engine. A water-cooled V8 version for the 964 could be ready a year earlier. The air-cooled 3.3-liter boxer engine of the 930 could also be a possibility. The development costs for the new engines are expected to be between 40 and 120 million marks, a hefty sum for the small car maker. The Indy-V8 would also leave no room for turbos, despite the exhaust system specially developed for the 965.

So another plan is devised: a new V8 engine is being developed that will be used in both the four-door 989 and the 965 and will have a displacement between 3.5 and 4.2 liters. A smaller V6 variant will then follow with a cylinder capacity between 2.6 and 3.2 liters, that is the intention. However, this plan also did not last long. On December 8, 1988, the development of the 965 was definitively stopped. 15 prototypes go into the shredder, leaving the only remaining prototype in front of us today, which can be called the first 911 to have a water-cooled rear engine. The experiences gained during the test drives with the heat management of the Audi V8 and the radiator placed in the nose can be used in the newly approved Boxster and 996 projects. What about the 965? On April 30, 1992, the engineers of the brand noted the last note in the logbook of the all-important link between Porsche’s past and future. “The advice is to keep the 965 L7 available for testing.” Then it became quiet around the groundbreaking Porsche.

This article originally appeared in AutoWeek Classics issue 11 of 2018.