A Short History of the Porsche 934
The Porsche 934 was a development of the Turbo 911 (the 930) for Group 4 racing – hence the name 934. Porsche built approximately 400 examples of the 934 for two years between 1976 and 1977, with some variation in specifications over the two years of production.
The cars were all fitted with turbo-charged flat-6 engines, early cars produced 480 bhp and later models turned out over 550 bhp – considerable power given the 1,090 kilogram kerb weight. The 0 to 62 mph time is 3.9 seconds and the top speed is approximately 190 mph – not bad for a car that still had much of its original trim fitted.
The 934 was a tour de force in the world of GT racing, it won the European GT Championship and the American Trans-Am series, it also won the 1977 Australian Sports Car Championship. Upgraded examples of the Porsche 934 would still be racing competitively right into the 1980s, and today original examples are highly sought after by collectors.
A Short History of the Porsche 935
The Porsche 935 was the Group 5 racing version of the Porsche 930 turbo, Group 5 regulations allowed far more freedom to modify cars – so long as the silhouette when viewed from the front remained close to the publicly available road going version.
Porsche used the same basic flat-6 as the type 934, though actual specifications varied significantly over the model’s production run. Early engines produced 560 bhp and later models were capable of over 840 bhp with prodigious torque figures thanks to hefty turbochargers.
Group 5 regulations allowed for far more creative bodywork, so the 935 had wide fender flares, a large rear wing, and later models did away with the original Porsche 911 headlights in favour of the more aerodynamically efficient flachbau (flatnose) that would later be offered to Porsche customers through the sonderwunsch (special wish) program.
The Porsche 935 was staggering successful in the world of motorsport, it won the 1979 24 Hours of Le Mans outright, and won the 24 Hours of Daytona and the 12 Hours of Sebring 6 times each. It would remain competitive for years after production ended, with its last major victory being at the 1984 12 Hours of Sebring in the IMSA GTP class.
The Porsche 934/5
The Porsche 934/5 was built specifically to compete in the American IMSA GT Championship (International Motorsports Association), event organisers wouldn’t permit the Porsche 935 for fears it would dominate – so the Porsche 934 was upgraded using as many 935 parts as was permitted by the rules. The resulting cars were called the 934/5 or the 934½ (in the USA).
The permitted changes included wider wheels, wider fender flares, a 935 rear wing, and Bosch mechanical injection instead of the K-Jetronic system originally used on the 934. The resulting cars were quicker than the 934 and slower than the 935 – which is what the IMSA had wanted in order to allow American cars of the era to compete effectively.
A number of European teams applied the 934/5 upgrades to their 934s where the rules allowed, including the famous Kremer Group 4 car shown here. It has just 3 races listed in its original ONS-Wagenpass – the International ADAC-Eifelrennen at the Nürburgring on 1st May 1977, the Flugplatzrennen, Mainz-Finthen on 20th May 1977 (round 5 of the Deutsche Automobil-Rennsport Meisterschaft) and the 4th ADAC-Rundstreckenrennen at Diepholz Airport in Germany.
After its short competition life it was stored for many years before being bought by Professor Michael Rudnig – who sent it for recommissioning at respected German Porsche specialists PS-Automobile. Since its resurrection its been campaigned at the 2008 AvD-Oldtimer Grand Prix at the Nürburgring and the FHR-Langstreckencup at Hockenheim in 2007, and it’s now being offered for auction by Bonhams in race-ready condition, with its ONS-Wagenpass, the DMSB-Wagenpass from 2006, and German Historic road-registration documents.
If you’d like to read more about the car or register to bid you can click here to visit the listing. As an aside, the Martini-liveried Volkswagen T2 Transporter shown in some of these images is for sale at the same auction, and you can click here to view its listing.
Images courtesy of Bonhams
Articles that Ben has written have been covered on CNN, Popular Mechanics, Smithsonian Magazine, Road & Track Magazine, the official Pinterest blog, the official eBay Motors blog, BuzzFeed, Autoweek Magazine, Wired Magazine, Autoblog, Gear Patrol, Jalopnik, The Verge, and many more.
Silodrome was founded by Ben back in 2010, in the years since the site has grown to become a world leader in the alternative and vintage motoring sector, with well over a million monthly readers from around the world and many hundreds of thousands of followers on social media.