Thank Frankel it’s Friday: the lightest racing Porsche ever is coming to Goodwood

Actually ‘Bergspyder’ was a name used on a few 1960s Porsche hillclimb cars, but among those who know, calling a car the Bergspyder can refer only to one machine: the 1968 909 Bergspyder. Today hillclimbing is a sport populated by specialist but affordable machines, often built at and run from the homes of those who drive them. But half a century ago it was so important that works factory teams like Porsche and Ferrari built dedicated machines and employed specialist drivers to contest the highly prized European Hillclimb championship. And that was the purpose of the Bergspyder.

So now you’re expecting me to tell you about all the events it won. But it didn’t: it was only entered for two, and came third and second respectively, on both occasions behind the Porsche 910 Bergspyder it was designed to replace. So it’s a 51 year old car designed to compete in a tiny niche of the sport that wasn’t even as good as its predecessor. What is all the fuss about?

Well, with the Bergspyder it was not so much what it did, as what it was. Which is the lightest racing car Porsche ever produced, and I suspect just about the lightest car of any kind produced by a mainstream manufacturer. It weighed just 384kg and if you want that put into some kind of perspective, the absurdly lightweight Lotus 48 that was its contemporary in Formula 2, had a smaller engine and was the work of lightweight obsessive Colin Chapman. And it weighed 420kg.

And it was the extent to which its creator, Ferdinand Piëch (who would follow the Bergspyder with the 917 and then become arguably the most influential industrialist in the car industry), went to reduce its weight that provides the fascination.

I’ll start with the basics. There wasn’t much he could do about the 2-litre flat 8 engine, which was derived from the 1962 F1 car. But it didn’t need an alternator because even a small battery will provide enough sparks to get a car up a short hill. It had a spidery spaceframe chassis as you might expect, but with aluminium rather than steel tubes. On this was draped polyester bodywork that was in places less than 1mm thick.

Then Piëch got really clever. To negate the need for a fuel pump, he put just 15 litres of petrol in a bag and encased that bag in a titanium shell, pressurised with nitrogen which would squeeze the bag and force the fuel into the engine. What very little wiring was made not from copper but silver thread of all things. The springs were titanium, not steel.

But it is the brakes that revealed just how crazed was the quest to save every gramme. Piëch realised that if he made the discs from beryllium rather than cast iron he could reduce their weight from 3.2kg per corner to 848g, saving almost 10kg of unsprung mass, an incredible gain for such a light car. And because the car was so light and used for hillclimbing where gravity already tended to help out in the braking areas, the thermal loads could be kept with tolerances too. Great. There was only one drawback, and it was not the exorbitant cost of beryllium, but the dust it gave off when stressed. Calling it poisonous is putting it mildly: today it is ranked as a class one carcinogen alongside such delightful substances as asbestos, mustard gas and plutonium. And even that didn’t stop Piëch.

The car failed because it was completely undeveloped. Porsche’s ace hillclimber Gerhard Mitter (pictured) who scored a hat-trick of championships between 1966-68, tested it, but then declined to race it, leaving to Rolf Stommelen who thought it ‘lethal’ at high speeds. After two rounds the championship was over and Piëch’s hands more than full enough designing the 917.

The 909 Bergspyder was ditched before it ever got the chance to show its potential. How great it is, then, that we will be able to see it in action once more after all these years. All I want to know if whether it will still have its beryllium brakes, and who will be the lucky person who gets to drive it.

Photography courtesy of Motorsport Images/Porsche.