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The accident that claimed the life of Jo Siffert occurred on Sunday, 24 October 1971, at the 1971 World Championship Victory Race at Brands Hatch, England. After a crash caused by mechanical failure, his car rolled over and caught fire. His accident led to changed safety regulations.

Jo Siffert's funeral took place in his hometown of Fribourg, Switzerland. An estimated 50,000 people gathered in the streets for the procession, which famously featured his black-draped Porsche 917K leading the way from the university to the St. Leonhard Cemetery.

Chassis 053 was one of three 917s built with an experimental magnesium chassis in 1971. This trio were the last Group 5 917s of any kind; all subsequent derivatives would be to Group 7 trim (for the likes of Can-Am and Interserie racing).

The three magnesium chassis cars were numbered 051, 052 and 053. They followed the 917 Langheck (040 to 045) and the 36 original 917 chassis (001 to 036).

051 was used to determine fatigue rates. After 740km on Porsche’s rough road track at Weissach it underwent the Long Distance Life Test and was subsequently scrapped.

052 appeared at the 1971 Le Mans Test weekend in April. The plain white car ran with factory personnel under a John Wyer Automotive Engineering entry. Alongside the Martini International squad, Wyer’s Gulf-backed crew were managing Porsche’s racing effort for 1970 and ‘71. After the Le Mans Test, chassis 052 was scrapped with 1020km on the clock.

The last car, chassis 053, was the all bells-and-whistles example saved for the 1971 Le Mans 24 Hours. It appeared at la Sarthe brand new and largely un-tested. The colour scheme was a stunning white Martini livery.

Once again, factory personnel were on-hand to oversee the operation, on this occasion alongside the Martini International Racing Team crew headed by Hans-Dieter Dechent.

053 was allocated to Helmut Marko and Gijs van Lennep. They qualified fastest of the Kurzheck 917s in fifth. In first through third were a trio of 917 Langhecks (two from Gulf and one from Martini). Ahead of Marko / van Lennep was the Penske Ferrari 512 M in fourth.

After the first three hours, the top six cars were all on the same lap and Marko was fifth in 053. Shortly before 10pm though, the car was delayed for ten minutes by a thrown alternator belt. Nine hours in, Marko / van Lennep had recovered to fifth. During the darkness of Sunday morning, a rash of trouble for the lead cars (three 917 Langhecks and a Matra), saw 053 moved up the leaderboard.

Shortly after mid-distance, Marko / van Lannep swept into lead, a position made more comfortable when one of the Langheck 917s moved into second at 7am. When the much-delayed chasing Matra went out shortly before 10am, the Porsche drivers were told to not push. Helmut Marko and Gijs van Lennep secured Porsche’s second Le Mans win on the bounce.

053 was immediately retired to the Porsche factory collection. On March 5th 1973 it appeared alongside the new 911 Carrera RSR at the annual Martini Racing press conference held at the Pavilion d’Armenonville in the Bois de Boulogne.

At this early stage, a prolonged factory assault on a major series was out of the question. Porsche’s 904 GTS was already the dominant force in the under two-litre class of the World Sportscar Championship and, for 1965, the world series would again run to the Group 3 rules that favoured extreme limited production models like the 904 as opposed to true Grand Tourers such as the 911.

By contrast, the European Touring Car Championship was organised to Group 2 rules and comfortably enough 911s had been built to satisfy the 1000-car production requirement for entry. However, the financial requirement of a season-long commitment didn’t fit with Porsche’s plans.

Porsche’s public relations manager and racing department chief, Huschke von Hanstein, reasoned the ideal platform for the 911 was rallying. The car’s rear-engined layout was well-suited to the special stages and very few modifications would be required to field a potentially front-running car.

By far the most prestigious event on the international calendar was the Monte Carlo Rally. Held every January, it was winter’s highest profile motor sport contest and attracted major media interest. To contest the Monte, a Ruby Red 1965 model year 911 Coupe (chassis 300055, also known as R1) was plucked from the production line. It underwent careful preparation but deviated only slightly from the standard specification. Modifications included uprated rear brakes, a rear anti-roll bar, Boge front dampers and a long-range 100-litre fuel tank.

The Type 901/02 engine was equipped with polished ports, hot camshafts, Weber carburettors, a lightened flywheel, platinum spark plugs and free-flow exhaust. The compression ratio was increased from 9.1 to 9.8:1 and output rose from 130bhp at 6100rpm to 160bhp at 6600rpm. Porsche modified the standard five-speed transmission to include a ZF limited-slip differential, lower final drive ratio and competition clutch.

Three Marchal spot lights were fitted, two on the front lid and the one on the roof. A rear traction bar was added for the co-driver to stand on. Leather straps were fitted above the engine cover for the co-driver to hold when the traction bar was in use. The cockpit was simply enhanced with standard rally fare: a roll cage, a driver’s bucket seat, a Halda Twinmaster and a pair of Heuer stopwatches. Despite the additional equipment, the absence of soundproofing and a few other unessential parts meant overall weight was unchanged at 1020kg.

Linge and Falk would not be the only factory representatives on hand at the 1965 Monte. Porsche also entered a works 904 Carrera GTS, a car that, in theory, seemed totally unsuited to the event. In 1964, the 904 in question (chassis 006) had successfully contested the Targa Florio, Nurburgring 1000km, Le Mans 24 Hours and Tour de France but a potentially snowy Monte would be an altogether different proposition. Eugen Bohringer would be accompanied by Rolf Wutherich in the low slung silver car. Porsche’s preparations for the 1965 Monte Carlo Rally began in late 1964. The crews went testing at Monza and also drove the gruelling course twice.

The nine-day event started on January 16th at points all over Europe. From Warsaw, Stockholm, Minsk, London, Frankfurt, Paris, Athens and Lisbon, competitors converged on the Alpine city of Chambery before ultimately heading to Monte Carlo. The Porsches were part of the Frankfurt party which lost five of its 26 starters en route to Chambery owing to masses of snow in Holland, Belgium and France. When the assembled crews finally made it away from Chambery, sudden blizzards in the Massif Central and Alpes Maritimes further decimated the entry. The 911 went on to finish a very respectable fifth overall and second in class 2/4 (behind the 904).

However while competition played little part in the 911’s conception, it played a continuous role in the Porsche company’s research and development. From its beginnings as a manufacturer Porsche had used an ambitious racing programme to prove new ideas before introducing them to production. By the time the design for the new 911 engine was being finalised Porsche were also looking for a next generation design for their forthcoming 904 race car.

A young Ferdinand Piech had just been appointed as head of the racing engine department and rather than create a separate competition design he decided to combine forces with the new 911 project. His position in the family enabled him to exert significant influence and thus aspects of the 911 engine design were driven by the needs of the race department. As a result the 911’s engine gained overhead cams, dry sump lubrication and a short stroke, all pre-requisites for a high revving and reliable race unit. It also gained it the attention of a genius engineer called Hans Mezger.

This rather fortuitous combination of commercial and racing interests meant that the 911 had unintended competition potential from the start. Porsche initially made no allowance for this other than homologating some alternative gear ratios, anti-roll bars and wheels. Customers who wanted to compete with their 911 were rather left to themselves while Porsche focussed on their purpose built 904 and 906 race cars. That didn’t stop them and in both Europe and North America the 911 was soon being entered in high level GT, touring car, hillclimb and rally championships.

By the end of 1966, such was their customers’ success, Porsche started to take notice. For the 1967 season they put together a basic “Rally Kit” of competition parts that could either be installed by the factory before delivery or retro-fitted to an existing road car. Porsche also issued a detailed bulletin containing an additional selection of competition parts and guidance as to how they might be used within different forms of racing. For the first time the race department started to turn its thoughts to how the pretty little road car could be tuned to best effect.

By now Ferdinand Piech had become head of the race department and as his subsequent career would prove he was not a man who did things by halves. He commissioned a project to see how far the 911 could be taken as a racing car with the 1967 911 R. The result was a devastatingly quick and agile machine which had the potential to dominate GT racing. There was one small hitch - Porsche would have to build 500 to qualify. Try as Piech might, he could not convince the company to take the risk and only a small series of 20 customer cars were eventually built.

Nevertheless the energy expended on the 911 R project was not entirely wasted. Encouraged by continued customer success, for 1968 the factory decided to produce two optimised racing versions of their standard road cars, one based on the 911L for Group 2 Touring cars and the other on the 911T for Group 3 GT. Neither of these were given a special name by the factory at the time but were referred to in documentation as “Homologation” versions or “H” for short, now also known as the 911 T/R.

Porsche had cleverly thought to widen the range of components that were listed in each model’s FIA homologation papers to include items whose only purpose was racing. This included more powerful engines and a lot of the equipment developed for the 911 R such as racing gearboxes, flared wheel arches, stiffened suspension, wider wheels, oil cooling systems, and stripped racing interiors.  However in the case of the 911T these parts were optional to the most basic and therefore lightest version of the road car thereby qualifying it to race at 903kg.

In order to help its customers navigate a now extensive catalogue of racing parts, Porsche produced a famous booklet entitled “Information Regarding Porsche Vehicles Used for Sports Purposes”. The starting point was usually to order a 911 T with Rally kit which meant the car was prepared for competition with a standard list of modifications. This may explain why these cars subsequently became known as 911 T/R. From there you could choose a completely bespoke specification depending on what you intended to do with the car and how deep your pockets were. Customers typically liaised directly with the race department where the orders were processed and the cars were prepared. A total of 22 T/H, or T/R, and 13 L/H, have so far been identified and it is does not appear that any two were exactly the same.

I1968 turned out to be an annus mirabilis for the 911. There is a memorable celebratory poster produced by the factory artist Strenger which lists 41 championships or major prizes won that year. The incredible versatility of the T/H in particular was demonstrated by achievements as diverse as an outright win at the Monte Carlo rally at the same time as GT class victories at the Targa Florio and Le Mans 24 Hours.

In 1969, the road going 911 went through a major revision with the move to a longer wheelbase and the adoption of fuel injection. However as far as 911 racing development was concerned not much happened as Porsche were consumed with the effort to build 25 917s in a quest to win Le Mans. Once that mission was complete their attention would return to the 911 but by then the GT racing rules had evolved to permit much more radical modification. Future racing 911s like the S/T and RSR would not have quite as direct a link to the car you could buy in the showroom.

In July 1968, having come incredibly close to an overall Le Mans victory with their 3-litre 908LH, Porsche audaciously commenced development of both the featherweight 908/3 and the heavy hitter 917. Ferdinand Piëch entrusted Chief Engineer Hans Mezger with leading the project, determined to win outright. With the gauntlet thrown down, Enzo Ferrari weaponised Fiat money -having sold his road car division in 1969 -to build the 512S to go head-to-head with Porsche, setting the stage for perhaps the two best years of sportscar racing ever in 1970 and 1971.

Yet, in its formative 1969 season, the original 917 was a tricky, under-developed beast even for experienced professionals. British privateer John Woolfe tragically lost control of his on the very first lap of Le Mans, perishing in the ensuing accident. Despite being somewhat maligned, the 917 proved its raw pace when Rolf Stommelen took pole and Vic Elford, co-driving with Richard Attwood, led the race for twenty hours, completing 327 laps before a cracked bellhousing forced their retirement.

When development started, Porsche was convinced they could build the car down to the class minimum weight limit of 800 kg based on the 908, which was 300 pounds lighter than its Alfa, Matra, and Ferrari 3-litre rivals. Utilizing the 908's aluminium spaceframe chassis as a guide, they shifted the cockpit forward to ensure the 908 wheelbase of 2300mm was maintained, despite the 12-cylinder engine being considerably longer than the flat-8. 908 practice was also applied by bonding the fibreglass body to the chassis. A design maxim from the start was exceptionally low drag to maximize top speed on the Mulsanne Straight, meaning two separate bodies for 'slow' and 'fast' tracks were always intended to be homologated.

To speed up development, Mezger used the exact same reciprocating parts, bore, stroke (85 x 66mm), valve, and port sizes of the 908, giving a capacity of 4494cc. Porsche believed it wouldn’t be necessary to build to the full 5-litre limit to dominate, so all fuel injection and valve timing settings were carried over, though the valve angle differed to allow cooling air passages—four valves per cylinder was never an option for this reason.

The power output shaft drove a triple gear-type oil pump, with four additional small oil pumps driven by the exhaust camshafts. Another shaft running symmetrically with the crank drove the two distributors of the electronic ignition, while the Bosch fuel injection pump was driven off the left-hand exhaust camshaft. The engine contained very few steel or iron parts; the crankcase, cam covers, and timing gear case were magnesium. The heads and cylinders were aluminium, while titanium was used for the conrods, auxiliary drive shafts, main output shaft, and later, the valves and springs. The cooling blower and air ducts were plastic.

Weighing 528 lbs, the 12-cylinder developed 542 bhp on its first dyno run, rising to 580 bhp at 8400 rpm by Le Mans. A new magnesium-cased gearbox handled the 376 lb-ft of torque, using Porsche synchromesh and a wet sump incorporating a ZF 'slippery diff' with a 75% locking factor. The 103 lb spaceframe chassis incorporated a tyre valve to allow it to be „inflated“, where a loss of air pressure indicated structural chassis cracks- sub-optimal in a car of this performance.

Suspension geometry mirrored the 908 but featured anti-dive geometry achieved by angling the upper and lower wishbone pivots to each other. Wishbones were used at the front with coil spring/damper units and an adjustable sway bar, while the rear featured a single top link, lower inverted wishbone, radius rods for fore and aft location, and Bilstein shock absorbers. Initially, 9x15-inch front and 12x15-inch rear magnesium alloy wheels were secured by a single centre aluminium lock nut, housing ATE aluminium calipers clamping cast-iron, ventilated discs.

The suspension was largely set up at the Nürburgring, where long travel, plenty of camber change, and rounded tread tyres were required. This translated poorly to other circuits where the car was under-tyred and the geometry deemed unsuitable. However, obsessive weight-saving using titanium for spherical joints, hubs, springs, gear lever, and steering column ensured the car tipped the scales below 800 kg.

The body was styled in-house via 1:5 and 1:1 scale plasticine models tested at the University of Stuttgart’s wind tunnel, with Charles Deutsch’s Paris-based SERA providing aerodynamic support later in the program. Both short and long tails were interchangeable, with the latter hitting 236 mph on the Mulsanne. To aid stability, front spoilers were fitted alongside ingenious mobile rear flaps connected to the suspension that automatically adjusted to modulate downforce. Only two weeks before Le Mans, the FIA banned these moveable aerodynamic devices following Colin Chapman's fragile high-wing failures on the Lotus 49s that caused massive accidents for Jochen Rindt and Graham Hill at Montjuich Park. Because the 917 was nearly undriveable without them, a dispensation allowed them at Le Mans, but they had to be removed thereafter. Twenty-five sets were made for homologation, but only two or three were ever used.

Piëch was determined to exhibit the car at Geneva in March 1969 to maximize publicity and force a tight production timeline. Starting in December 1968, 45 race mechanics split into 13 working groups at Werk 1 in Zuffenhausen to assemble the cars around the clock, briefly breaking for Christmas. Chassis construction was sub-contracted to Baur and fibreglass bodies to Waggonfabrik Rastatt. Chassis 917-001 arrived for final assembly on March 1st and was completed on March 10th, the evening before being dispatched to Geneva.

On March 12th, the motoring media gathered around the machine, which carried a price tag of DM140,000, a fraction of its development costs. On April 22nd, twenty-five 917s were lined up at Zuffenhausen for the CSI homologation count. Piëch cheekily offered inspectors the chance to drive any car, an offer they declined.

The public circuit debut at the March Le Mans test weekend was overshadowed by the death of Lucien Bianchi, whose Alfa Romeo Tipo 33 crashed over the Mulsanne hump. Meanwhile, Stommelen clocked a frighteningly unstable 3 minutes 30.7 seconds in the 917. As it turned out, no trackside fixes could cure this high-speed instability. The sportscar season opened wide as Roger Penske’s Lola T70 won Daytona and a JW Automotive Ford GT40 won Sebring. Porsche then struck back, dominating Brands Hatch and Monza with Jo Siffert and Brian Redman in the 908/02. The Targa Florio was a total 908 rout, with Porsche System Engineering entering six cars and taking the top four spots; no 917s were entered there.

At Spa, Siffert and Redman practiced the 917 but elected to race the 908LH for championship points, winning the race while Gerhard Mitter’s 917 retired on lap one with an engine failure from a potential over-rev at the start. For the Nürburgring 1000km, Porsche hired hardened pros Frank Gardner and David Piper to wrestle chassis 917-004 to eighth place after over six hours in the Green Hell so Gardner could provide development feedback, while 908/02s swept the top five spots.

Other than more power, 580bhp, and with the anti-dive geometry of the suspension reduced from a factor of 50% to 5%, the 917 arrived at Le Mans as designed. Fortunately, as described above, the cars were able to race with their adjustable rear wings -common-sense prevailed from a safety perspective. The 917 was still a long way from being a proven winner, leaving it once more to the dependable 908 -a machine originally destined for the smaller capacity classes-to take the fight straight to the top-tier weaponry.

After Le Mans, where Hans Herrmann’s 908LH narrowly lost to the Ickx/Oliver GT40 by 100 metres, Porsche skipped Watkins Glen with the 917 but won regardless with the 908/02. Intensive testing was then instigated by race engineer Peter Falk at the Nürburgring South Loop, the Weissach skid-pad, and Hockenheim to modify the frame and body. At the fast Zeltweg finale on the new Österreichring, a 917 entered by Karl von Wendt and driven by Siffert and Kurt Ahrens finally took a maiden victory against weak opposition, ahead of Richard Attwood and Brian Redman in a David Piper-entered 917K. These private entries were made because both drivers held options to buy the cars from Porsche’s surplus stock. At this stage, the 4.5-litre flat-12 raced with a small fixed rear spoiler, but the car remained fundamentally uncompetitive until a critical test at the Österreichring between October 14 and 17, 1969, changed history.

Engineers Peter Falk and Helmut Flegl met JW Automotive’s David Yorke and John Horsman, along with drivers Redman and Ahrens, to test Le Mans workhorses 917-006 and 917-008. Chasing a target time of 1:46.6 set by a Gulf Mirage M3, they could manage only a 1:48.2. During a pitstop, Horsman noticed a total lack of dead bugs and gnats on the rear deck, indicating that airflow was detaching completely from the contours of the body. Recognizing it as an aerodynamic issue rather than suspension geometry or tyres, Horsman, alongside mechanics Ermanno Cuoghi and Peter Davies, hastily fashioned a revised rear deck using aluminium sheet, rivets, and tape after the track closed. The next morning, a skeptical Redman stayed out for seven laps because he was enjoying the newfound stability so much. After replicating the modifications on 917-006 and switching to wider wheels and Firestone tyres (replacing Porsche's Dunlops), Ahrens shattered the target with a 1:43.2 lap.

Eugen Kolb’s design team rapidly productionised these changes into the short-tail 917K (Kurzheck), redesigning the rear window, creating a sight tunnel in the upswept tail, re-routing the exhausts to the open area behind the rear wheels, and creating new side pods. The nose profile was finalized with larger brake ducts and fender vents. Mechanically, the clutch was upgraded to a triple-plate Borg & Beck item, and the transmission housing was reinforced. A highly secretive follow-up test was scheduled at Daytona on November 19 and 20, where speedway employees were banned from the stands. Siffert, Ahrens, Rodriguez, and David Hobbs ran simulated endurance tests, trying both the 917K and a new longtail body that the drivers disliked. Hobbs accidentally buzzed an engine by pulling second gear instead of fourth, destroying his chance to partner Rodriguez for 1970; instead, the factory-paid pairing became Siffert/Redman, while JW hired Rodriguez and Leo Kinnunen, as Jacky Ickx had departed for Ferrari.

The Daytona tests inspired final tweaks: oil lines were routed through dedicated plumbing rather than chassis tubes to reduce cockpit heat, a D-shaped windscreen was created to improve vision on the high banking, the steering rack was refined, and a new front upright design eliminated brake pad taper wear. Upon returning, 917-011 was wind-tunnel tested at the University of Stuttgart, confirming acceptable drag and downforce.

Meanwhile, an open-top 917PA was sent to the US for Siffert to contest the late-1969 Can-Am series. Though blown away by the higher hp 7 and 8-litre McLarens of Bruce McLaren and Denny Hulme, the 917PA secured a second and third place, gathering vital data that would later fuel Porsche’s legendary turbocharged 917/10 and 917/30 assaults in 1972 and 1973. Porsche concluded a fantastic 1969 season by securing the Manufacturers’ Championship and the GT Trophy.

For 1970 and 1971, Porsche shifted strategy, outsourcing race operations to JW Automotive and Porsche-Salzburg while maintaining factory development, a decision that turned the heavily refined 917 into an indelible racing behemoth that permanently altered the landscape of motorsport.

For the 1961 Formula One season, the FIA introduced new regulations limiting engine displacement to 1.5 litres, bringing Formula One in line with Formula Two. This allowed Porsche to enter Formula One with only minor modifications to its existing Formula Two cars. However, it quickly became clear that the Porsche 787, derived from the 718, was outclassed by the competition in both engine performance and handling.

Porsche therefore decided to develop an entirely new Formula One car powered by an all-new flat-eight engine. The chassis, internally designated 804, was designed by Ferdinand Alexander Porsche and Hubert Mimler, while the new engine - developed by Hans Mezger- made its race debut at the 1962 Dutch Grand Prix.

During the development of the 804, Porsche’s new flat-eight engine was not yet ready, so early test cars were powered by the air-cooled 1.5-litre Type 547/6 flat-four from the Porsche 787. Known as the Michael May engine, it was based on the Fuhrmann engine and featured dry-sump lubrication along with twin overhead camshafts per cylinder bank driven by vertical shaft drives. Once development of the new air-cooled 1.5-litre Type 753 flat-eight was completed, it replaced the four-cylinder unit.

Its crankcase, cylinders and pistons were all constructed from lightweight alloy, while each cylinder bank was equipped with two overhead camshafts driven by vertical shafts. The engine featured a dry-sump lubrication system with a separate oil reservoir and a Bosch battery ignition system configured as a twin-ignition setup with four ignition coils and two distributors. Fuel was supplied by four twin-choke Weber carbs. With a compression ratio of 10.0:1, the Type 753 produced 180 hp at 9,200 rpm. Combined with an improved 718 six-speed manual and a ZF LSD, the 804 was capable of doing over 168 mph.

The car also featured a tubular steel spaceframe clothed in an aluminium body, double wishbone suspension with torsion bars and inboard dampers, and was the first Porsche racing car to employ disc brakes on all four wheels.

The factory team achieved two Formula racing victories with the 804, along with several points finishes. Despite its promising performances, Porsche withdrew from Formula One shortly before the end of the 1962 season, prior to the South African Grand Prix, and suspended all Formula racing development for nearly two decades.

Several factors contributed to the withdrawal. Many of the highly specialised Formula One components had to be sourced from suppliers in England, as no equivalent supply network existed in Germany, making development and logistics increasingly complex. At the same time, Porsche saw little opportunity to transfer Formula One technology to its production cars or to derive commercial value from the programme.

Another significant factor was Porsche’s impending acquisition of coachbuilder Reutter, a major financial commitment that made the costly Formula One programme difficult to justify. Instead, the company chose to focus its motorsport efforts entirely on production-based GT and sports cars, where racing success more directly benefited road-car development.

Porsche did not return to single-seater engine development until 1979, when it built a turbocharged engine based on the 935 powerplant for the Interscope Indy 500 project. The car ultimately never started the race due to regulatory issues.

First tested at Le Mans in April 1964, a 904/8 was driven to a prototype class victory in the Targa Florio and competed in the Nurburgring 1000km in the hands of Jo Bonnier and Richie Ginther. It also took part in the Le Mans 24 Hours in 1965, the 12 Hours of Reims and 1000km of Paris as well as two more Nurburgring 1000km races.

At the 1964 Targa Florio, two 904s occupied the two top steps of the podium, but these were both four-cam, flat-four engined 904s. The factory also entered a 904/8 (chassis #008), driven by Edgar Barth and Umberto Maglioli. Initially Barth showed the field what lay in store for them by leading in the 904/8 after the first lap, but a loose shock absorber mount resulted in a worrying spin. With repairs completed, the car went out again but it had too much ground to make up, and the promising pair of Barth/Maglioli would come home in sixth place overall.

Developed for endurance sports car racing, the 906 was a road-legal race car that competed in the FIA Group 4 Sports Car class against cars such as the Ferrari Dino 206 P. Based on the “Ollon-Villars Bergspyder”, Porsche developed the 906 Carrera 6, which soon became known simply as the Carrera 6.

To save weight, some of the chassis tubes were used as oil lines between the engine and the oil cooler. While the 906 Ollon-Villars used suspension components from a Lotus Formula One car, the homologation version of the 906 adopted the 904’s suspension components and 5-lug 15-inch Porsche wheels (7 inches at the front, 9 inches at the rear).

Thanks to the extensive use of lightweight materials such as magnesium and titanium, the Type 901/20 engine used in the 904/6 and 906/6 was 54 kg (119 lb) lighter than the Type 901/01 engine fitted to the 911. Unlike the 904, which had a single fuel tank at the front, the 906 was equipped with two side-mounted tanks. This reduced the influence of fuel load on handling, as the balance was less affected between a full and an empty tank.

The FIA had previously required at least 100 cars to be produced in order to qualify for the Sports Car category, as had been the case with the 904. However, the regulations were changed, reducing the requirement to just 50 cars. Sports Cars were still required to have two seats, so a small “passenger seat” had to be installed for homologation purposes.

The first 906 Carrera 6 coupés were chassis numbers 906-016 and 906-017, both serving as prototypes. The third Carrera 6 built, and the first delivered to a customer, carried chassis number 906-101.

The first race for the 906 coupé was the Daytona 24 Hours on February 5–6, 1966. With its 2-litre engine, the Porsche was naturally targeting a class victory rather than an overall win. As the required production run of 50 cars for FIA Sports Car homologation had not yet been completed, the 906 was entered in the 2-litre Prototype class, where it secured victory with Hans Herrmann and Herbert Linge behind the wheel. The Porsche finished sixth overall, behind the 7-litre Ford GT40s and a 4.4-litre Ferrari. 

At the Sebring 12 Hours on March 26, 1966, the factory-entered 906 K Coupé (chassis 906-103), driven by Hans Herrmann, Joe Buzzetta and Gerhard Mitter, achieved another 2-litre Prototype class victory and finished fourth overall behind three Ford GT40s. The front corners of the factory 906 were fitted with additional spoilers to improve aerodynamic performance. The race was overshadowed by a tragic accident during the night. Mario Andretti’s Ferrari suffered a gearbox failure that locked the rear wheels, causing the car to crash. A privately entered 906 (#48, chassis 906-105) following behind was unable to avoid the accident, resulting in a collision that claimed the lives of four people. Earlier in the race, GT40 driver Bob McLean had also lost his life in an accident.

The next major success for the 906 came at the Monza 1000 km race on April 25, 1966. The factory racing team entered chassis 906-128, a 906 K Coupé driven by Gerhard Mitter and Hans Herrmann. The Porsche secured victory in the 2-litre Prototype class and finished fourth overall behind the larger-engined Ferraris and two Ford GT40s.

By the end of April 1966, Porsche had completed the required production run of 50 cars, and the 906 was homologated for FIA Group 4 Sports Car competition from May onwards. In reality, production continued beyond the required number, with approximately sixty 906 K (Kurzheck, or short-tail) coupés being built. Five of these cars were built with fuel injection as the 906 E, while some carbureted Carrera 6s were later converted to E specification.

Porsche’s new era of racing success, driven by Ferdinand Piëch’s engineering ambitions, began with victory at the 1966 Targa Florio. The winning 906 was driven by Herbert Müller and Willy Mairesse. A Ferrari finished second, while another Porsche Carrera 6 secured third place with Vincenzo Arena and Antonio Pucci behind the wheel.

For the 1966 24 Hours of Le Mans, Porsche developed long-tail LH (“Langheck”) versions of the 906 to improve high-speed performance on the Mulsanne Straight. From this point onwards, the standard short-tail versions became known as the 906 K (“Kurzheck”, meaning short-tail in German). The Le Mans podium was dominated by the 7-litre Ford GT40s, but Porsche achieved an impressive result in the 2-litre Prototype class. Three 906 LHs finished behind the winning GT40s, while seventh overall went to the 906 K (chassis 906-143, #58) of Rolf Stommelen and Günther Klass, competing in the 2-litre Sports Car class. Only two other 906 Ks entered in this class, and neither managed to finish.

At the Zeltweg 500 km race on September 11, 1966, three Porsche 906s swept the podium. First place went to Gerhard Mitter and Hans Herrmann in chassis 906-128 (#14), the same car that had previously won the Targa Florio. Jo Siffert finished second in chassis 906-137 (#12), while Udo Schütz and Herbert Linge took third in chassis 906-124 (#15). Fourth place went to a Ford GT40, followed by two more 906s.

Although the 906 Carrera 6 had been introduced and homologated in 1966, Porsche’s racing engineers quickly realized that the 15-inch five-lug wheels were not ideal for competition use. Therefore, when the Porsche 910 was introduced, the car adopted 13-inch center-lock Formula One wheels fitted with specially developed racing tyres.

Four factory 906s were equipped with the 270 hp Type 771 flat-eight engine, already used in the 904/8. These cars, known as the 906/8, were developed with the ambition of creating an overall winner for events such as the 24 Hours of Le Mans and the Nürburgring 1000 km race. However, they failed to achieve the level of success Porsche had hoped for.

Developed for the 1968 European Hill Climb Championship, the Porsche 909 Bergspyder represented the ultimate expression of Porsche’s obsession with designing highly specialized racing cars for a single competitive objective.

Weighing just 375 kg (826 lbs), it featured an aluminum chassis, a fiberglass body, titanium suspension components and even beryllium brake discs. Fuel was supplied from a pressurized 16-liter titanium tank, eliminating the need for a conventional fuel pump. Power came from a 2.0-liter flat-eight producing 275 hp, enough to propel the featherweight from 0-100 km/h (62 mph) in under 2.5 seconds. In the relentless pursuit of weight distribution and agility, the driver’s feet were positioned ahead of the front axle.

Although the 909 appeared in only two hill climbs during 1968, its influence extended far beyond its brief competition career. The lessons learned from the 909 Bergspyder helped shape the 908/3, the nimble and featherweight counterpart to Porsche’s mighty flat twelve-powered 917. The 908/3 justified Porsche’s investment handsomely, claiming back-to-back victories in the Targa Florio in 1970 and 1971 and securing a podium sweep at the 1970 and 1971 Nürburgring 1000 km.