When Porsche’s engineering chief set project leader Manfred Bantle the brief of building a car capable of competing in the toughest off-road rallies as well as endurance racing, little did he know what the proposed solution would be.
The Gruppe B concept that resulted – along with the 959 homologation special that it sired – would be among the most complex roadgoing cars ever created up to that point. To be eligible for Group B racing Porsche would have to build at least 200 examples of the 959; in the end, there were considerably more buyers happy to part with the requisite £150,000.
Although the core structure is pure 911, the outer body is a mix of ultra-strong, lightweight composite panels plus aluminium-skinned doors and front lid.
Part of the car’s appeal lay in its twin-turbo flat six that developed a heady 450bhp to give a 197mph top speed, along with 0-62mph in just 3.7 seconds. The 2.85-litre engine was racebred, dating back to the 935 and developed via Group C, its capacity defined by the handicap system applied to turbocharged cars racing in the 4.0-litre class.
Unlike any other 911-based road car before the 996, it features water-cooled cylinder heads, and is constructed from magnesium alloy with titanium conrods and crankshaft. The twin KKK turbochargers work sequentially to reduce lag, the second spooling up from around 4500rpm – the same time as a second set of injectors starts squirting even more fuel into the combustion chambers.
The 959 was the father of all the four-wheel-drive 911s that followed. Torque is transferred forward from the gearbox via a propshaft to the front differential, where clutch packs distribute the torque fed to the front wheels.
A dial on the centre console applies settings for different road conditions, apportioning a maximum of 40% torque forwards – so the 959 is always predominantly rear-wheel drive. The system was hugely advanced, employing computer-controlled hydraulics. There are several ECUs around the car, so their mass isn’t concentrated in one place. It doesn’t sound that amazing now, but back then it was revolutionary, and as a result the 959 is still something deeply special.
Which 959 to buy?
The 959’s cabin is based on the 964’s, so while this may seem like a stupid thing to suggest – make sure that what you’re buying is a genuine 959. Over the years there have been some 964-based replicas offered and to the untrained eye they can look pretty convincing. That’s until you remove the front and rear covers; then the 959’s complexity is there for all to see.
If you’re able to buy one of the dozen cars that originally came to the UK through official channels, you could be in for an easier life. Import a car from Europe or the US and you could have to pay thousands to have the headlamps converted to dip correctly. All 959s were left-hand drive but UK cars got a speedometer in mph rather than kph.
A car that still sports its original tool kit is very desirable. Stored in a leather pouch, the roster of tools runs to a centre-lock wheelnut socket along with a top-quality torque wrench. All cars came with a huge spec; the only options were heated seats, an alarm and sports seats with electric height adjustment.
Buyers could choose from Comfort or Sport editions when new, but just half a dozen or so of the latter were built. These were stripped of the variable ride height, central locking, electric windows, air-con and even the passenger-side door mirror. In the process 100kg was lost, but Porsche didn’t charge any less, which is why just about everyone opted for the Comfort edition. Perhaps unsurprisingly, it’s the Sport model that is the most valuable today (see prices below).
Performance and specs
Porsche 959 Comfort
||2850cc, twin-turbo six-cylinder
||450bhp @ 6500rpm
||369lb ft @ 5500rpm
||Six-speed manual, four-wheel drive
|Price when new
Dimensions and weight
• Plenty of 959s have been damaged over the years and while most have been repaired to a very high standard, some have been bodged. The kevlar and aluminium body panels need specialist attention so ensure everything lines up properly – all gaps should be tight and even. At this price level, there really is no excuse for poor workmanship.
• Check the aluminium metal doorskins, which are easily distorted. A knock on the door-mounted mirror can lead to the doorskin being damaged.
• Any parts unique to the 959 are hugely expensive. Some parts look very similar to the contemporary 911 but they’re not the same. Items such as exhausts, windscreens and those body panels are all unique and have eye-watering price tags attached.
• The 959 was originally fitted with centre locking magnesium alloy wheels, which were designed to work specifically with the Dunlop ‘Denlock’ tyre bead locking system. Today, Bridgestone produce RE71 tires to the correct Porsche size and specification, however getting hold of a fresh set can be difficult as production is extremely limited. That’s why it’s worth checking the condition and age of the rubber currently fitted to the car.
• There are also lots of parts that aren’t available any more, such as the engine cover. When it was last listed, you’d have had to pay over £11,000 to buy a new one. So be very careful about buying a car that’s got any missing or damaged parts as they may be irreplaceable, or obscenely expensive.
• The 959’s engine isn’t based on the 911’s; instead it’s derived from the flat-six found in the 935 and 956 racers. While the cylinder barrels are air-cooled, the four-valve double-overhead cam heads are water-cooled.
• Few 959s have covered a significant mileage so engine problems are more likely to stem from a lack of use, rather than wear. Cars driven sparingly can work fine if maintained properly, so make sure the engine has been started regularly and the oil and coolant changed frequently too; the latter helps prevent internal corrosion.
• The PSK (Porsche-Steuer Kupplung) four-wheel drive system is very complex and not always reliable. The front and rear differentials are both fitted with clutches and oil pumps that can play up, so see if any warning lights illuminate on the test drive and feel for any jerkiness when accelerating through the gears.
• Most of these cars are used very sparingly, so a conditioner should be used to keep the battery in good nick. Replacing the Bosch battery is a pain, so make sure that what’s fitted works okay.
1983: The Gruppe B concept is shown at the Frankfurt motor show in October. It features a twin-turbo 2.85-litre flat-six, four-wheel drive plus lots of carbon-fibre and kevlar in its construction.
1985: Porsche enters the Paris-Dakar Rally with three 959s fitted with 230bhp 3.2 Carrera engines. All three retired through mechanical failure. At the Frankfurt motor show the production 959 is shown. Priced at $225,000, Porsche loses money on each one.
1986: Another three cars are entered into the Paris-Dakar with detuned 959 engines. This time they come first, second and fifth.
1987: The first deliveries of road-going 959s begin in September.
1988: The final car is built. The production-car tally is 292 along with 37 prototypes and pre-production cars.
1992: Another eight cars are built from spare parts. Sold to selected collectors, these cars feature speed-sensitive suspension and are now hugely collectible.
Owners clubs, forums and websites
Summary and prices
Although undervalued for many years, the 959 has risen sharply in recent years. Expect to pay somewhere in the region of £750,000-£1m for a good example of the more common ‘Komfort’ model. Condition and mileage play a big part in values, though, so an ultra-low mileage car could very much be worth a significant premium over something with a few miles under its belt.
The very rare Sport model carries a huge premium, and could potentially sell for upwards of £1.5m. Obviously there are also competition-spec long-distance rally cars. Although rarely seen out in public, let alone on sale, these could quite easily sell for twice the price of a regular 959.