Porsche 906 K Coupé

Premiere: 1966 January

© Porsche
906 Carrera 6 906 E Carrera 6 906/8 Coupé (only chassis 906-142)
Engine 2.0 flat-6 with Weber carburetors 2.0 flat-6 with fuel injection 2.2 flat-8
Engine type Porsche type 901/20 Porsche type 901/21 Porsche type 771
Power 154 kW @8000 rpm (max 8500 rpm) 162 kW 198 kW
Torque 20 mkg/145 lb-ft/196 Nm @6000 rpm
Gearbox Type 906 5-speed manual with LSD Type 906 5-speed manual with LSD Type 906 5-speed manual with LSD

When the Porsche 901 was forced to be renamed to 911, it was not the same case with the other Porsche model names with zero in the middle. The 904 coupé got its commercial name Carrera GTS before the 901 was renamed to 911 and the type 906 coupé was called as the Carrera 6 from the beginning.

The 906 was designed by Erwin Komenda. He had set the design language for Porsche cars decades earlier with the 60 K10 and 356.

Design genius Erwin Komenda and automotive genius Ferry Porsche (photo from 1951)© Porsche

While the 904 had one fuel tank in front, the 906 was equipped with two tanks on the sides. This way the level of the fuel didn't affect the handling as much as on the 904 with full tank versus empty tank.

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The mid-engined 906 was constructed with tubular spaceframe. The two fuel tanks had a total capacity of around 100 litres.© Porsche

To save weight some of the tubes in the frame were used as oil channels between the engine and the oil cooler. This technique was already used on the Porsche 804 F1 car. While the 906 Ollon-Villars had the suspension parts from Lotus F1 car, the homologation 906 used the 904 suspension components and 5-bolt 15" Porsche wheels (7" front, 9" rear).

Thanks to lightweight materials (magnesium, titanium), the 901/20 engine of the 904/6 and 906/6 was 54 kg/119 lb lighter than the 901/01 engine in the 911 (both are 2-litre boxer-6 engines).

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Twin-spark 901/20 racing engine © Porsche

Earlier FIA had stated that at least 100 cars had to be produced in order to qualify for the sports car class (the case with the 904), but the rules were changed and now only 50 cars had to be made. The sports class cars had to have 2 seats by the rules, so a smaller "passenger seat" had to be fitted. The first 906 Carrera 6 coupés were chassis 906-016 and 906-017. These were prototypes. The third Carrera 6 built, and the first sold to a customer, had chassis number 906-101.

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Porsche 906 Carrera 6 (chassis 906-017) premiere in the beginning of January 1966 at Porsche Werk 1 in Stuttgart-Zuffenhausen © Porsche
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© Porsche

While the 906-010, initially known as Ollon-Villars spyder, was converted to a coupé, it had the doors fixed from the front edge, but the production 906s had doors fixed from the top. This way the thin doors were not pulled away from the body by aerodynamic forces at top speed and the gullwing doors got more attention from the photographers.

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Gerhard Mitter© Porsche
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This is how you picked your 906 at the factory © Porsche
© Porsche

The first race for the 906 coupé was the Daytona 24 hours on February 5-6, 1966. It was the first 24 hour race at the speedway on Daytona Beach, Florida. The 2-litre Porsche was naturally looking only for a class win. As the 50 car production run demanded for homologation in FIA sports car class was not completed yet, the 906 was signed up in the 2-litre prototype class, which it won with Hans Herrmann and Herbert Linge driving the car. The overall result was sixth after 7-litre Ford GT40s and a 4.4-litre Ferrari.

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1966 February, Daytona 24 hour race 2-litre prototype class winner 906 Carrera 6 (chassis number 906-017) #15 driven by Hans Herrmann/Herbert Linge© Porsche

At the Sebring 12 hour race on March 26, 1966, factory team 906 K Coupe (906-103) driven by Hans Herrmann/Joe Buzzetta/Gerhard Mitter scored 2-litre prototype class victory and scored 4th overall after three GT40s. The front corners of the factory entered 906 were fitted with spoilers. The event was overshadowed by a tragic accident in the night where Mario Andretti's Ferrari had a gearbox failure, locked up the wheels, and the privately entered 906 #48 (chassis 906-105) following him, crashed totally killing 4 people as a result. The GT40 driver Bob McLean had killed himself earlier in the race. All the deaths at Sebring in 1966 almost killed the race from happening again.

The next success for the 906 came at the Monza 1000 km race on April 25, 1966. The factory racing team entered 906 K Coupé (906-128) driven by Gerhard Mitter/Hans Herrmann scored the 2-litre prototype class victory and were 4th overall after larger engined Ferrari and two Ford GT40s.

Porsche made 50 cars by the end of April 1966 and the 906 was homologated from May 1966 in Group 4 GT. In reality more 906 were made, including 60 906 K (short tail) Coupés. One of them had a 2.2-litre 8-cylinder engine and the rest 59 were 6-cylinder Carrera 6. Five Carrera 6 were born with the fuel injection engine as 906 E and some carburetor Carrera 6 were converted to "E"-versions. The first fuel injected engine was installed in the prototype chassis 906-017 (that earlier had won the class at Daytona 24). The car was used for test driving at Targa Florio. Targa Florio was also the first race for 906 E (chassis 906-143).

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906 E (type 901/21) engine © Porsche
Hans Mezger, Porsche engine engineer and leader of racing department © Porsche

Porsche's racing success sparked by visionary Ferdinand Piëch started with the overall victory of the 1966 Targa Florio. The winning 906 was driven by Herbert Müller/Willy Mairesse. The second place was taken with a Ferrari and the third place again with Porsche Carrera 6, driven by Vincenzo Arena/Antonio Pucci.

1966 May 8, Targa Florio winner 906 Carrera 6 #148 (chassis 906-128) Herbert Müller/Willy Mairesse © Porsche

The sole 2.2-litre 8-cylinder 906 made (chassis 906-142) had to retire from the 1966 Targa Florio race because of an accident and it had bad luck also at the 1966 Nürburgring 1000 km. In the private hands the car might have raced also later (although not known if with 8-cylinder engine).

1966 June 3, training before Nürburgring 1000 km race, Jo Siffert's 906 K not only has front corner spoilers, but also a longer nose© Lothar Spurzem (via Wikimedia Commons)

For 1966 Le Mans long-tail (Langheck or "LH") versions were made and now the standard 906 were called was 906 K ("K" for Kurzheck, short-tail in German). The Le Mans podium was taken by 7-litre GT40s, followed by three 906 LHs of the 2-litre prototype class and the 7th finisher was a 906 K (906-143, #58) of Rolf Stommelen/Günther Klass of the 2-litre sports car class. In this class there were only two other 906 Ks, but those didn't finish.

At the Zeltweg 500 km race on September 11, 1966, three Porsche 906 took the podium: 1st Gerhard Mitter/Hans Herrmann (#14, chassis 906-128, the Targa Florio winner), 2nd Jo Siffert (906-137, #12), 3rd Udo Schütz/Herbert Linge (906-124, #15). 4th place was taken by a GT40 and then two more 906 followed.

1966 October 9, Innsbruck airport, Preis von Tirol sees a Porsche 906 1-2-3 victory: 1st Gerhard Mitter #93 (chassis 906-128), 2nd Jochen Rindt #94 (906-137), 3rd Ben Pon #96 (906-134). © Erwin Jelinek / Technisches Museum Wien
1966 October 16, Vienna-Aspern airport, Donau Pokal. The event also saw a Porsche 906 1-2-3 victory. Winner Gijs van Lennep #74 (chassis 906-134) and 2nd Jochen Rindt #76 (906-128) drifting. 3rd place went to Gerhard Mitter #75 (906-137). © Erwin Jelinek / Technisches Museum Wien
1966 October 16, Vienna-Aspern airport, Jochen Rindt goes front wheel in the air© Erwin Jelinek / Technisches Museum Wien
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© Porsche
Interesting photo of a 906 with rear cover removed (here on August 25, 1968 at Zeltweg 500 km) © Arthur Fenzlau / Technisches Museum Wien
Billet of the 1:5 body model used for initial aerodynamic tests before the real body was made © James Herne / Stuttcars.com

While the 906 Carrera 6 was launched and homologated in 1966, Porsche racing engineers knew the 15" 5-bolt wheels were not the best for racing, so, 13" central nut Formula 1 wheels with special tyres were adapted and the Porsche 910 was born.


Article © James Herne / Stuttcars.com


Continue to 906 LH Coupé
Anniversaries
Jul, 10 – 51st birthday of the 910 (1966)
Jul, 16 – 13th birthday of the 911 997 (2004)
Aug, 19 – 78th birthday of the type 64 (1939)
Aug, 29 – 52nd birthday of the 906 (1965)
Sep, 03 – 142nd birthday anniversary of Ferdinand Porsche (1875)