What's the difference between a Porsche 956 and 962?

956 and 962 – oceans apart

Porsche wanted the 956 to be a globally eligible sportscar, racing in the European World Sportscar Championship (WSC) and indeed, the International Motor Sports Association (IMSA) series. Unfortunately, that wasn’t to be, with new safety rules in IMSA mandating steel roll cages and frontal impact zones. Twin-turbocharged engines were also shy of the rules in IMSA, meaning the 956’s 3.0-litre twin-turbo 935 motor wouldn’t do.

The 962 was the 956 rejigged for IMSA rules, with a cage, a longer wheelbase putting the pedal box behind the front wheels and a single-turbo flat-six engine. That extra wheelbase can be spotted between the door shut and the front wheel well. If it’s bigger, it’s a 962.

Stay side-on to the cars and you’ll also notice the noses are slightly different in shape, with the 956 featuring a longer downwards curve from the top of the wheel-arch to the tip of the nose. The 962 is stubbier, with the extra cabin length taken out of the front overhang. Round the back, an IMSA-spec 962 will also feed its exhaust out through the diffuser, as opposed to through side exits per WSC-spec cars. The 962C is a combination of the newer 962 design but to WSC- and Le Mans-ready specifications.

Such was the adaptability of these cars that some 956s were converted to 962 specifications. IMSA and WSC specifications were interchangeable and some crashed chassis were even salvaged by third parties.

High-downforce, low-drag

These are far easier to tell between, with the difference brought into sharp focus with such a variety of cars next to each other for the 79^th Members’ Meeting presented by Audrain Motorsport. The so-called ‘Langheck’ or ‘Longtail’ version runs a longer rear clam with a much lower rear wing. Contrast to the higher downforce version, which runs its clam shorter and its wing a lot higher, with the single-plane element canted to a much more aggressive angle.

Of course the wing is a supplementary element in the 956 and 962’s aerodynamic arsenal, at least in factory trims, given these are cars that rely heavily on underfloor ground effect-generated downforce.

It’s thought that the high downforce specification cars generally doubled the downforce of the slippery Longtail cars, which could hit 220mph-plus at Le Mans. The early high-downforce cars were also thought to benefit from more downforce and power than an F1 car their era.

Modified cars

Beyond Porsche’s own developments – engines of varying capacities, with different fuelling and turbo solutions, as well as the experimental double-clutch gearbox – a number of teams bought and modified these cars in the face of increasing competition. Lancia, Mercedes and Jaguar were extracting serious performance from their cars, albeit sans the reliability and consistency of the aging Porsches. Kremer, Joest, Richard Lloyd/GTi Engineering, Dauer and more all built outwards from the Porsche platform to combat newer cars and evolving regulations and it was all with encouragement, if not always support, from the Porsche factory.

Perhaps the most visually separate derivation of the 962 was the RLR GTi car, of which two are representing at 79MM. It’s not just the revised lights, wheel covers and re-specced aero that defines the GTi. It’s near enough an all-new car, with a Peter Stevens-redesigned alloy honeycomb chassis underpinning it, by comparison to the sheet tubs of the standard cars. These were built to oppose the growing might of Tom Walkinshaw’s Jaguars and the Sauber-Mercedes in the late 1980s, to no avail, at least at La Sarthe. Following Hans-Joachim Stuck, Derek Bell and Al Holbert’s win in 1987, in a factory 962C, Porsche’s domination at the 24 hours, if not on a championship level in series around the world, temporarily waned.

That was until Dauer’s GT loophole. Porsche realised Dauer’s road-prepared 962s could homologate a 962 for the GT class in 1993, that could pan out quicker than the now naturally-aspirated top-flight Group C machinery. With support from Joest racing, at the time Porsche’s factory team, Yannick Dalmas, Hurley Haywood and Mauro Baldi drove the GT-spec car to victory ahead of the late-era Toyota Group C racers. Other road conversions were produced by Schuppan, Koenig Specials, DP Motorsports and more.

The 956 and 962’s story of evolution over the course of more than a decade is enormous and we’ve definitely not covered every derivation here. That an adapted GT car could win Le Mans 11 years on from the original 956’s debut speaks volumes of what has to be one of the most dominant sports racers of all time, achieving as much through sheer versatility, adaptability and dependability. Porsche generally does motorsport on an industrial scale, never more so than with its Group C titans.

Photography by Mark Riccioni and Stuart Price.