1975 Porsche 934 911 RSR

The Carrera RSR solidified the earlier successes of 911s in European rallies and major road races. The unprecedented success of the Porsche 971 during 1969-1972 limited the 911's racing sponsorship primarily in privateer hands. However, with the decline in interest in prototype racing and the 1974 demise of the CanAm series, suddenly production based cars such as the RSR were elevated to headline status and the factory went out of its way to assist customers. In 1973 Porsche quickly switched focus to the 3-liter European GT Championship (FIA Group 4). Porsche created the road legal Carrera RS by modifying the std 911 with a beefed up, lightweight engine, 917 brakes, adjustable shocks, wide body work and wheels, plus the signature whale tail spoiler. The RSR, strictly a race-car, had still a more powerful engine, coil over shocks, and even wider bodywork and wheels. 109 RSRs were built in 1974.

Success was immediate. The RSR dominated the world GT scene from 1973 to 1975. Penske/Donahue selected the 1973 RS for the first IROC series in 1973. RSRs placed 5th thru 10th overall and first in GT class at LeMans in 1976.

Successful RSR competitors include: Atkin, Busby, Donahue, Dyer, Elford, Follmer, Gregg, Haywood, Holbert, Minter, Kemer, Earle, Robinson, Joest, Loos, Faure, Fitzpatrick, Hagestad.

By Daniel Vaughan | Feb 2008

Vehicle Profiles


The 1977 24 Hours of Daytona was the first race of the 1977 season and what later became known as IMSA's 'Turbo Era.' Regulations finally allowed the new Porsche 935 to compete in the 24 Hours. Not satisfied with the reliability of the new cars, Hu....[continue reading]


This car is the second 934 of the 31 Porsche built. Born December 3, 1975, this car raced successfully for seven season, through 1982. Long-time Porsche expert Bruce Anderson describes it as 'the most successful 934 to race in international competi....[continue reading]


Chassis Num: 911 560 9114

This 1975 3.0L Carrera RSR was ordered by Peter Gregg, from Porsche's Racing Development Group at Weissach. It was one of the last RSR Carrera's ever completed by the factory. Between 1976 and 1979 this car, owned and driven by Jim Busby in 1976 and ....[continue reading]


Chassis Num: 9115609118
Engine Num: 6850162

This is a 1975 Porsche 911 RSR with serial number 9115609118. This RSR is an original un-restored example of the normally aspirated RSR era. Vasek Polak purchased this car at the end of the RSR production run in late 1974.....[continue reading]


Chassis Num: 0050004

This Wally's Jean car was built by Kremer Racing for a Dutch Blue Jeans manufacturer. Kremer was a firm founded in 1962 by brothers Erwin and Manfred Kremer, and was the first team that entered the Porsche 911 in International races. This car was rac....[continue reading]


Chassis Num: 9115609122

This factory built race car was sold to Jim Busby by Vasek Polak Racing. Jim Busby raced this car with great success and podium finishing in IMSA. The car was sponsored by Beverly Porsche/Audi owner William Karges and Mitcom Equipment. This car is no....[continue reading]


Chassis Num: 911 560 9121

This 3.0-liter Carrera RSR with chassis number 9121 is one of the last 'customer' examples produced by Porsche for the 1975 season. The car was delivered to Wartwig Bertrams and was originally powered by engine number 7840167. The car was raced by th....[continue reading]


Chassis Num: 911 560 9122
Engine Num: 6850165
Build Num: 1046997

This Porsche 911 Carrera RSR 3.0-liter is an ex-Jim Busby IMSA race car that was imported by Vasek Polak and sold to Beverly Hills Porsche+Audi. It is Grand Prix White with Busby's 1975 IMSA season livery 'Beverly Hills Porsche+Audi.' This RSR is the....[continue reading]


This RSR was raced by Diego Febles. During Diego's race career he was fortunate to be among the friends of Peter Gregg and the Brumos Racing Team. Febles was able to acquire a series of Porsche 911 variants from the Brumos team at the end of each rac....[continue reading]

Chassis #: 911 560 9114 
Chassis #: 9115609118 
Chassis #: 0050004 
Chassis #: 9115609122 
Chassis #: 911 560 9121 
Chassis #: 911 560 9122 


The Porsche 934 was a specially prepared racing version of the Porsche 911 Turbo built to satisfy the FIA Group 4 rules and to continue the marque's success in that class. Homologation requirements stated at least 400 road-going cars were to be built within a two year period. The dimensions of the road and race cars were to be equal and modifications throughout were to be limited, except for safety. A roll cage, fuel cell, and other common racing safety features were required. These restrictions made the class very competitive; the limitation of displacement and weight made competition even more fierce. The allowable limit of displacement size was directly tied to the vehicles overall weight. The more weight, the higher the displacement allowed; the lower the weight, the less displacement permitted.

Porsche introduced the new 930 model in 1975. This 911 Turbo Type 930 would serve as the basis for the new Group 4 racer, which would be dubbed the Type 934. During the development of the 930, the needs of the 934 were taken into consideration and planned appropriately. To satisfy the rules stating 'limited modifications', Porsche gave the 930 much strong and better components than needed, thus having it included on the 934. For example, components on the transmission were designed to handle the rigorous 485 horsepower from the Type 934 engine, making it under-utilized for the 290 horsepower Type 930.

The Type 934 was fitted with a turbocharger which helped the engine achieve over 480 horsepower. In 1977 the valves were enlarged and horsepower grew to over 550. To satisfy the 1120 kg rule, the interior was stripped many non-essential items. Major modifications were not allowed, which meant the electric windows remained in tact.

In both the European GT Championship and the TransAm Championship, the Porsche 934 was a dominant force. The highlights were from 1977 through 1979 when it captured three successive class victories at the legendary 24 Hours of LeMans.

By Daniel Vaughan | Feb 2008
One of the most successful shapes of all time, every young schoolboy can spot a Porsche 911 when one drives by. Porsche purists can wax poetic on the timeless lines of the series. And surely timeless is the right word. Introduced in 1964, even the very first 911 looks remarkably similar to today's iteration. The smooth, elegant contours, though, have occasionally taken on a distinctively sinister flair. Case in point, the 911-based Porsche 934.

Introduced as a hardcore racer's Porsche, only a small number of 934s were made for street use. Of the 31 true 934s built, most if not all were destined for a hard life of race use. The street cars were produced only to fulfill a requirement of the FIA's Group 4 regulations. The Porsche 934 was built to dominate on the tracks, not to be flaunted on the streets.

Successful in its Group 4 class, the 934 proved a proud successor to the impressive RSR. The brutish 934 was an awe-inspiring piece of machinery. Despite its menacing stance, though, the 934 was more civilized than one would expect. The reason was simple. The 930, a turbocharged variant of the 911 on which the 934 was based, weighed little more than the lowest allowable weight for its displacement level according to FIA regulations. Porsche, therefore, was only permitted to shave a mere 20kg off of the 930 when they transformed it into the fire-breathing 934. With barely any weight to lose, the 934 was able to retain many of the creature comforts of the luxurious 930.

Despite the minimal weight loss necessary, Porsche did some ingenious work when leaning out the 934. Sure, you could have your race-ready banshee with factory door panels and power windows. But Porsche managed to shave enough pounds off the rest of the car that the Stuttgart company was forced to add weight. While adding weight to a racecar sounds like an idea created simply to torture the vehicle's creators, the FIA regulations actually gave Porsche the ability to load the car with ballast used to improve the weight distribution.

Even with its optimally placed ballast and advanced aerodynamics, the 934 was a handful on the track. The inherent tail-happiness of the 911 design, the manic power levels, and the fairly high weight created a vehicle that could break loose easily. But with such a fierce face, the violence could almost be expected.

Porsche employed a huge air dam up front to provide ample air supply to the Behr water radiators, oil cooler, and front brakes. Many components of the 934's body were made of lightweight fiberglass, including the wide fender flares and legendary whale tail rear spoiler. These racy items weren't just for show: the 934 initially produced 485hp at 7000rpm, with 540hp available from subsequent versions produced in 1977.

Proving the great dynamics of a trademark Porsche design, the 934 was a formidable beast with wild wings that remained every ounce a 911. The car will always be remembered as one of the last spectacular Porsche racers to remain so true to that hallmark curvature. But power windows and resemblance to lesser models aside, the 934 was a devastating weapon in the hands of any driver brave and skilled enough to harness its awesome performance.

The site www.qv500.com supplied information for this story, and contains useful guides to many prominent supercars.

By Evan Acuña
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