The Porsche 928 Transaxle

The 928 was an unexpected breakthrough for Porsche; both as an elegant high-performance sports car and grand touring vehicle.

Modern Porsches would later follow its path, even the 911 becoming easier for anyone to drive – yet the 928 was an early step toward this revolution.

Engine

As Porsche prepared to end production of its beloved 911, they set about searching for an alternative that would strengthen its image as an automotive innovator. Enter the front-engine, rear-drive 928 grand tourer; its sleek form combined aspects of sports car and luxury sedan design into one sleek package. Though never as popular as its predecessor, this grand tourer was nonetheless an undoubted success, marking a new era for front-engine Porsches.

Ferdinand Piech led an engineering team working on the 928, composed of engineers such as Wolfhelm Gorissen, Manfred Bantle and Helmut Flegl. Their first test object may seem peculiar today: an Opel Admiral fitted out not only with suspension components for their new model but also fitted out with an additional steering wheel in its back seat – something similar could be said of today’s test object!

Engineers employed this testing vehicle as the foundation of their development process for an all-alloy M28 engine that featured multiple unusual features, including large bore spacing that allowed a low hood line and all aluminum cylinder barrels instead of steel ones – this allowed it to generate substantial power while remaining lightweight, making it suitable for road and track use.

Production progressed and the design continued to change. Manual transmission cars utilized a single-disc clutch while automatic versions used a larger torque converter; furthermore, pistons were fitted with strengthened skirts for improved oil drainage while monitoring was conducted to check spark advance timing.

By the end of production, a more powerful version was available with a 5.0-liter V8 producing 221 kW; 306 horsepower in Europe only – known as “S” model in North America and Europe.

This 1995 model features an engine and transaxle matching the numbers as confirmed by its Porsche Certificate of Authenticity and VINAnalytics build report. Additionally, its extensive service history includes receiving new timing belt, Continental ExtremeContact tires, brake system refreshening, four-wheel alignment services as well as electronic sensor sorting services – making this highly desirable car among Porsche enthusiasts.

Transmission

The Porsche 928 was one of the most innovative cars ever produced by Germany’s automaker, yet its true brilliance lay in its drivetrain system – front engine/rear wheel drive setup was unique to it and set it apart from all competitors – thus cementing its legendary status among automotive enthusiasts worldwide.

As part of its development, several different layouts were considered when designing this car. Unfortunately, due to technical and legislative considerations like fitting an engine, transmission, catalytic converter(s), exhaust pipe system, fuel tank and driver compartment all into a relatively limited space within its housing; they were eventually all set aside and the final design chosen: front engine rear-wheel drive vehicle.

Porsche engineers quickly recognized that most buyers preferred three or four speed automatic models and so 80% of all 928s produced were equipped with this transmission option.

By the time production ended in 1995, nearly 400,000 had been sold. To commemorate this achievement, Porsche Museum is featuring several cars from this era in an exhibition called “The Transaxle Era: From the 924 to the 928.”

The original 928 was available as both coupe and convertible models. Constructed entirely out of aluminum, its interior was minimalist. Furthermore, these vehicles featured an innovative forward-facing front engine design which allowed more passenger room while improving stability and handling.

Early years saw great success for the 928 both on the track and in showroom sales. It even won European Car of the Year honors in 1978 – usually awarded only to mainstream hatchbacks or sedans from major automakers.

Over the following decade, its performance only got better and faster, becoming one of the fastest sports cars in its class and even outpacing many exotic vehicles of its day. Furthermore, driving one was both comfortable and relaxing thanks to large brakes and its four-speed automatic transmission option.

Axle

As more drivers push themselves to hit–and even surpass–their limits, the need for more stable vehicles becomes ever clearer. When entering a curve at high speed and taking your foot off the gas, immediately countersteering is necessary to prevent fishtailing and loss of control – this is particularly crucial in sports cars and other high-performance vehicles where drivers frequently approach–and often exceed–their threshold.

Porsche developed the Weissach axle to combat this issue, with its self-stabilizing equalization characteristic ensuring an even distance between rear and front of car. This innovative solution provides more controlled rides by eliminating torque and yaw effects for improved stability and driving safety.

Harrer characterizes the Weissach axle as “an evolution in suspension technology that continues to drive our work today.” This system has since evolved to better address both longitudinal and lateral forces; indeed, recent Porsche Cayenne and Macan SUV models use this same system found on 928s.

Harrer predicts that in the future more vehicles will utilize Weissach axles due to their increasing sophistication and demand for sophisticated handling capabilities.

One of the standout features of the Porsche 928 is its convenient trunk release on the right side, which is so effortless I spit at you when opening it. I cannot think of another car that does it better; it demonstrates just how carefully Porsche engineers thought through every aspect of design process. Other great touches included dash brightness and wiper delay controls that might seem trivial but are actually so useful they should come standard on all cars.

Suspension

The Porsche 928 GT car was an enormous GT car equipped with an enormous V8 engine and luxurious interior. The rear-wheel drive layout gave it low center of gravity and impressive handling characteristics; while its lightweight aluminum body made for sleekness. A true grand tourer designed to appeal to upscale buyers. It offered comfortable long journeys while its back seats could fold for increased loading space.

The 928’s suspension was tailored for long distance travel and comfort, while its Weissach axle enhanced driving stability and safety. This rear-wheel steering system enabled it to maintain neutral and stable positioning even at high speeds when cornering, reduced acceleration squat, dive under brake, isolated noise from road noise into cabin and used linkages and shock absorbers to manage car roll.

Initial suspension tuning of the 928 was subpar. Rear wheels would frequently spin during turns. Engineers devised special shock absorbers specifically tailored for this model that proved much more effective and allowed tuning for smoother rides without compromising handling performance.

Porsche steadily upgraded the 928 as it gained in popularity, adding features like revised suspension settings, larger brakes and an updated exhaust system in 1986. These improvements were only available on cars marked “CS” or “SE”, requiring different ignition maps and piston oil squirters in order to function effectively.

Porsche also offered a Competition Package option in the US market, consisting of front and rear spoilers, 16-inch flat disc wheels, sport seats, and Bilstein shock absorbers. However, this was limited to 928S models only and few early manual transmission models. By the late 90s, however, its fans had taken to it; its build quality, luxurious driving environment justified its high price tag.