930 Turbo Carrera

Thank you for your kind words Tony. It never ceases to impress all who encounter her...

 

“Porsche gained serious experience with turbochargers on its mighty Can-Am 917’s but it didn’t fit an experimental Turbo to the 911 until 1972. In 1973 the car was tested and shown at Frankfurt and in 1974 Carrera RSR Turbos were raced while development of a roadgoing Turbo Matured”
- Karl Ludvisgen, Excellence was Expected.

A mockup of the rumoured 911 Turbo was shown in Frankfurt and in the 1973 Paris Salon and showed the bulging rear bodywork and suspension from the Carrera RS 3.0 that had yet to make its IROC Riverside Debut. This was the series organized by Roger Penske; for the best drivers in the world all to be driving identical cars.

Roger didn’t now what kind of cars to use, but Mark Donohue advised:

“‘Roger, there’s no question about it, the only way to go is with factory backed Carreras’ In the first place, he wouldn’t have to build them. Second, they wouldn’t be anywhere near as expensive as any other completely race-prepared car. Third, they had to be as identically equal as any race cars ever built. And fourth-and foremost-the Carrera had to be the most reliable car available. Dr. Fuhrman had told me once that the car couldn’t be broken-as long as it wasn’t over-revved and as long as it was shifted correctly. And that was really quite true. They came with Can-Am brakes, dry-sump lubrication, fuel injection, good ignition, oil coolers, stainless-steel exhaust, and a lot of other things only racing people can appreciate...The Carrera is-without a doubt-the very best off-the-shelf production race car available at any price”
-Mark Donohue, The Unfair Advantage

The first 911 Turbo prototype, The Carrera Turbo RSR racing car, used the 3.0L 911 RS as a starting point, and then installed the blown engine. The Turbo RSR had an engine displacement that when multiplied by the regulations’ turbo charging factor of 1.4 gave very close to the 3,000cc limit for Group 5-2,143cc The car had to be competitive with the 480hp normally aspirated 3.0L competition. The Carrera RSR turbo appeared for its first race in April 25, 1974 in Monza. Porsche quoted power output of 450hp at 1.3 bar of boost (19psi). With the addition of a water to air intercooler 20psi was reliably maintained raising power to 470hp. This car was steadily developed throughout the 1974 season earning many podium finishes, including a 2nd place in the 1974 Le Mans 24 hours. Read an article on this car here.

After the season ended, Porsche released some of the cars performance statistics:

0-60mph in 3.2 sec, 0-124mph in 8.8sec, and it could corner up to 1.45g. Porsche also admitted that they had not found a tachometer with a needle that could respond fast enough to keep track of the rising engine revolutions while the car was on boost.

For the 1975 Le Mans race, a Turbocharged Porsche Coupe placed 15th in the race. What is significant about this placing is that the car was one of the first a production Porsche 911 Turbos. Porsche settled on using the 3.0 Liter engine for the production car, up from the 2.7L of the current 911’s to better counter the effects of Turbo lag. There was some debate at Porsche as to offer the car as a stripped out racer at $15,000 or a fully equipped luxury version at $25,000. Some felt that a $25,000 Porsche 911 wouldn’t be able to find many buyers. When the production 911 Turbo was introduced at the Paris Saloon in Oct 1974 it was fully equipped and priced at $25,000.

The 3L Turbo used a KKK turbo running at a maximum of .8bar of boost and using Bosch K Jetronic Fuel Injection. Power was de-tuned from 280hp to 260 because some at Porsche felt that the power came on too strongly, and could catch inexperienced drivers out. For the American market Thermal Reactors were installed that lowered the power to 234 hp (and increased the heat in the engine bay). A new 4 speed trans-axle was designed for the car, as Porsche didn’t have a production gearbox that would cope with the turbos torque. The engine still delivered electrifying performance, 0-60 in less than 6 seconds, and a top speed of over 150mph.

A component originally planned for the Type 930 (Porsche’s internal designation) was the radially vented and laterally drilled brake disk developed for the 917 race car. The first 930’s made due with Carrera 2.7 brakes. Also in the first production cars 15” forged aluminum wheels were chosen, 7” front and 8” rear wearing 185/70 front and 215/60 rear tires. They were used through the 1976 season, the cars first year in the US, to meet US ride height regulations. Optional rubber in Europe were the 205/50 and 225/50 section Pirelli P7 radials. The early cars also had no boost pressure gauge.

Production wise, only 7 cars were made before the end of 1974 and those were mostly press demonstrators.

In 1976 the car was marketed in North America as the ‘Turbo Carrera’ as that market didn’t have the Carrera model. In May 1976, a month after Porsche had hoped to sell 500 examples, a ceremony in Zuffenhausen celebrated the delivery of the 1,000 turbo. Read an article on the first Porsche Turbo Carrera here.

For the 1977 model year, listing for $28,000 in the US and DM 67,500 in Germany, the 930 received the same upgrades as the rest of the 911 line including face-level air ducts and power assisted brakes, which were welcome in the Turbo. A boost gauge was added to the bottom of the tachometer. The most obvious change to the 1977 turbo was the addition of 16” wheels on 205/55 and 225/50 section rubber.

For racing Porsche developed the 934 to compete in Group 4 endurance racing and the 935 to compete in Group 5, and the 936 for Group 6.

Group 4 required a manufacturer to homologate 400 road versions of the car in 2 production years, something Porsche easily accomplished with the 930. Regulations for a 3.0 liter turbocharged car specified a minimum weight of 2,470lbs, so Porsche left the luxury equipment in place, and made the 934 the first racing Porsche to run with electric windows. 31 934’s were built for the 1976 season. These used the standard 930 bodyshell and suspension, but with beefed up hubs, wider tires, and riveted on fender flares and a deep front spoiler with oil cooler. It used the 930 engine with the same 6.5:1 compression ratio but with the addition of an water-to-air inter-cooler and running 20psi of boost. Power was quoted at 485hp.

The 934 was not an easy car to drive, Al Holbert quoting, “With the Turbo it always seems like I’m out of control in the damn thing. That is the only way it goes fast. It is very responsive to brake pedal and steering effort, just like the street cars.... In fact, when I get into a 911 after driving a Porsche racing car, id doesn’t feel like I’m in a completely different car.”

The 935 was quite a bit more highly developed, though it still retained the basics of body shell and engine. The factory only made two 935’s for the 1976 racing season but offered ‘kits’ to convert 934’s to 935’s. 935’s used a 2,857cc version of the Turbo engine and 21psi of boost to generate a 590hp factory rating, though the model was constantly developed and hp increased over the years to something above 800 with water cooled 4-Valve heads. The 935 also showed Porsches inventiveness with their interpretation of the regulations concerning fender shape which was open-this of course was the birth of the ‘flat nose’ 911’s... The rear bodywork was also completely new with substantially different rear fenders and a much larger rear wing. The 935 stunned its drivers with its power, and had a higher top speed than contemporary Grand Prix cars.

These 934 and 935 Porsche racing cars would go on to completely dominate endurance racing in the Group 4 and 5 class well into the 1980’s. It wasn’t unusual for Porsches to sweep the top 6 positions in any of the races they contested. Perhaps the 911’s finest hour came at the 1979 Le Mans 24 hours when a 935 outlasted the Prototypes and won the race overall, Paul Newmann, co-driving another 935 placed 2nd a 934 coming in 4th. Porsche 934‘s won their class at Le Mans in 1977, 1979, and 1981 and in the 1979 race it finished a full 30 laps ahead of its nearest Group 4 rival. Read an article on a comparison between the 930, 934 and 935 here.

The 936 was a full tube-frame open cockpit racing car, the successor to the 917, and sharing only the basic engine with the 930. It used a 2.1L version of the Turbo flat 6, running at 22psi of boost. It was rated at 540hp which was enough to propel the 1,650lb car to a 217mph top speed. A 936 was entered in the 1977 Le Mans and despite some drama, won just ahead of the Alpine Renaults.

The famous British Journalist, and navigator with Sterling Moss in the 1955 Mille Miglia winning Mercedes-Benz SLR, had this to say about the 930; “I never thought the day would come when Ferraris, Maseratis, Lamborghinis and similar exotica would pale into insignificance in my book of motoring... but that day came with the Porsche Turbo. I found it hard to accept that a Porsche could be worth over 20,000pounds. However, when I returned it a week later I had changed my mind completely, convinced that Porsche were offering 20,000pounds of performance, engineering, quality, and above all else, integrity.”
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Road & Track's memorable article.
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R&T's Jan 1977 article featuring the road car plus the giant-killers..
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Thanks for the compliment on the thread.

And you are right, NOT the same car, although claimed elsewhere to be. Just shows you have to check!

 

Thank you. The 2 Mc Queen slate grey Porsches together.. pic by Johnei
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The USA headlamp bezels look so much better on USA cars I think.

 

Yes! It is a 1976. Wow, very groovy

Chassis number?

 

Cool! Thanks for sharing...

 

I saw that. What a mess..

 

Silver must be the most prolific color?

California-registered 3.0 930.
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Speaking of green 3.0 930s, Alois Ruf has massaged his own and gently 'breathed' upon the engine somewhat

Its a 1977 and it graced the tuner’s stand at a recent show.

Oak Green metallic, green leather interior with Black Watch Tartan seat inserts!

Note front unit with oil cooler and oversize rear wing!
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