There’s a legend of a long-tailed monster that roamed the race tracks of the late 1970s. Many have heard of it, though few have seen it to confirm the truth of its existence. It’s rumoured to have been part racing car, part monster. Somewhere underneath its elongated body was supposedly a Porsche 911, though that was difficult to believe. It oozed power: long straights disappeared in seconds. It spat flame: 850hp of twin-turbocharged insanity lurked in the rear. It ate the opposition for breakfast.

Me, I know the legend is real. I’ve seen it. I know the Moby Dick lives and breathes, even today…

I caught my first glimpse of a Porsche 935/78 at this year’s Goodwood Festival Of Speed, with Porsche’s museum car on show as part of the Martini anniversary celebration. The 935/78 is one of those magical racecars that you don’t necessarily expect to see in real life – but when you do, all the implanted memories and stories come flooding back.

Ferrari may have long been the chosen ones in Formula 1, with many complaining of the team’s blessed existence and seeming immunity to rules that others are bound to follow. The same could be said of Porsche in sportscars, which is perhaps why it often stays chastely silent on the subject of others pushing rulebooks. Porsche has always explored the boundaries in sportscars.

There was the Porsche 911 GT1 of the late ’90s, something supposedly based on a road-going 911 but which in reality had the curve of a rear window and the tail-lights from the real thing. Then back in 1978 was the ultimate iteration of the Porsche 935: the 935/78 – nicknamed Moby Dick.

With customer cars flooding grids, 935 variants took apart championships across the world between ’76 and ’82, winning a third of the 370 races entered.

Porsche’s new shovel-nosed 911 930 Turbo road car had been unleashed on the world in 1975, and its racing variant followed the year after. Competing in the perfect storm that was the Group 5 set of silhouette regulations, the 935/76 was the beginning of a series of awesome mutations that took the car to more and more extreme variants.

The following year’s 935/77 continued the trend, but nothing prepared people for what was to emerge in 1978.

Hulk style, first the fenders expanded outwards, then the sills, then the wings and aero grew – both by Porsche’s hand and under the warped minds of privateers teams like Kremer. But the mothership outdid them all. Behold the 935/78.

Loopholes, damn loopholes. BMW’s front-engined 320 had required a rules break to allow the floor to be cut away for the exhaust mounting, so Porsche used that change to remove the entire floor plan of the base 911, lowering the 935/78 by 10cm.

Aero rules were loose at best, so Porsche’s legendary engineer Norbert Singer was able to stretch out every part of the car’s bodywork for this Le Mans-bound weapon, leaving the remains of the donor 911 stranded in the middle of an island of extravagant fenders and bodywork. For this ultimate iteration, the traditional flat-six was enlarged to 3.2 litres and changed to water-cooled cylinder heads due to the employment of twin overhead camshafts.

The increased capacity combined with the turbos gave the driver 750hp to deal with, in a car that barely pushed 1,000kg. The heart of the Moby Dick volcano contained the pair of enormous turbos and their epic lag. Speed was the aim, flame was the gain.

One interesting result of the car’s design brief was that the driving position was moved to the right, to go with the clockwise nature of the Circuit De La Sarthe and to improve weight distribution.

Vented and cross-drilled brakes improved retardation power (reassuring, given all that power), but the only thing that familiar to previous generation 935s was the cross-braced nose with its fuel tank and fillers.

The original promotional photoshoot still contains the most beautiful pictures taken of the car, with its ’70s film softness and slight yellowing just adding to the effect.

The Moby Dick nickname for the 935/78 was an obvious epithet. The tail goes on forever, reaching out back down the track, keeping hold of every last breath of air, and the Martini stripes melt away as if the sheer speed of the car was blowing the red and blue lines down the sides.

The prototype that was run out at Paul Ricard on the cusp of the season was different in many ways, and not just with the lack of stripes to help define the shape. The prototype’s doors reached out to match the line of the front and rear fenders: one thing that scrutineers wouldn’t pass, so the ‘original’ 911 doors were retrofitted. The rear wing was also refined and raised right up into the airflow by the time the car had its race debut. And it’s amazing the difference a livery can make. Compare the bare prototype…

…to the look of the car that would be campaigned, with its unique and subtle usage of the Martini colours. Although that can be said of the majority of the brand’s liveries, as each model the famous stripes have adorned use the design in a way that best suit the shape of the car. It’s that ‘melting’ effect and the minimalism that make the impact so effective.

The legendary status of the Moby Dick is helped by how few races it competed in. The extreme body had been developed specifically for the 1978 Le Mans 24 Hours, but chassis #006 also raced in four other rounds that year.

The car’s debut was at Silverstone, where it won in the hands of Jochen Mass and Jacky Ickx by seven laps from a chasing Kremer 935. Its pole and fastest lap times were only a couple of seconds slower than at that year’s Formula 1 Grand Prix…

So Le Mans: the goal for the year. Manfred Shurti and Ralf Stommelen took up the challenge, and qualifying went perfectly. As planned, #43 was obscenely quick down the straights, blasting past even the Group 6 prototypes and achieving a terrifying velocity of 226mph on the run to Mulsanne.

The car lined up third, but the race went less to plan – niggling engine troubles dropped Moby Dick out of contention at the front, and the pair eventually finished eighth overall, behind even three customer 935s. The final three races were memorable for all the wrong reasons. Ickx and Schurti campaigned Moby Dick at the Six Hours Of Vallelunga, with a DNF the result after the engine failed with just seven minutes to go and the car leading.

Ickx then drove solo at the Norisring, he finished 21st in the 200 mile Norisring Trophae (brake failure crippled the 935/78) before non-starting in the DRM race that followed, which capped the 935/78’s short but spectacular career. Witnessing the Moby Dick around the stop-start blast bullring of the Norisring must be something that sticks in the mind of everyone who was there… And with that, Moby Dick was retired to the Porsche Museum.

The story wasn’t over though: a further development, the 935/78-81 chassis, #JR-001, was produced independently by Joest Racing. After an initial run-out in Europe at the 1981 DRM round at Zolder, the car was transported to the States, liveried in another iconic branding scheme – in this case the red and yellow of MOMO – and raced in a whole slew of IMSA weekends.

The chassis briefly returned to Europe at the beginning of 1982 for the Silverstone World Endurance Championship and DRM Wunstorf races, before a second chassis – #JR002 – was brought out for Le Mans. John Fitzpatrick and David Hobbs ran the JDavid livery to fourth overall, and winning the IMSA GTX class against prototype opposition.

Both the MOMO and JDavid cars raced on into 1983, using 2.6, 3 and 3.2-litre flat six turbos at various stages (though none as potent as the original Moby Dick), racing in Europe and the USA. There was even one glorious opportunity to see both race side by side at the 1983 Riverside Six Hours, though the race was marred when Rolf Stommelen lost his life in the JDavid car, becoming the only fatality associated with the 935.

Two 935/78 chassis were built in period by the factory, the race car and a spare, which has recently been built up into a complete car. When will I get to see Moby Dick again? May never, but at least I can now say I’ve paid homage to one of the most gloriously extreme Porsches ever raced.