The Porsche 935 was the Stuttgart manufacturer’s answer to the FIA’s Group 5 class regulations, making it eligible for the World Championship of Makes. The first Porsche car in this so-called ‘Silhouette’ series, was introduced for the start of the 1976 season. The factory entered 935s in both the World Championship of Makes and the World Sportscar Championship, winning both titles, the latter with almost three times the number of points as the second-placed manufacturer.
The factory 935/77 cars featured a twin turbo setup and boasted an extra 40 bhp, now up at 630 bhp. At the end of the 1977 season, Porsche decided to withdraw from the World Championship of Makes and to let its strong and capable band of privateer teams carry the company flag. The factory made one exception in ’78, and that was to run their very special 935/78 ‘Moby Dick’ in the Le Mans 24 Hours that year.
In 1977, Porsche built and sold a small number of 935s to private teams, such as the Kremer Brothers and Georg Loos, these being similar to the 1976 cars. While the Georg Loos cars were essentially factory maintained, the Kremer Brothers did a lot of their own modifications, and became very successful in the process. In 1976, Kremer built the 935 K1, in 1977 they developed the K2, and the K3 was introduced at the start of the 1979 season. The 935 Kremer K3 went on to win the 1979 Le Mans 24 Hours, with a factory-specification Porsche 935 finishing second.
The Porsche 935 won over 150 races worldwide, with more than 20 class victories. It won the 1979 Le Mans 24 Hours outright, along with six victories at both the Daytona 24 Hours and Sebring 12 Hours. It was undefeated in the German DRM Championship between 1977 and 1979 and claimed three Nürburgring 1000 km victories. The 935 also took victory in the FIA World Championship for Makes each year from 1976 to 1979. In its day, the Porsche 935 dominated endurance racing around the world, in a manner never before seen.
To those who feel that this era was all about Porsche’s domination of the racing scene, perhaps it would be appropriate to mention that as from as early as 1966, every newly developed Porsche race car was subjected to the most rigorous testing regime imaginable. In addition to the usual engine bench testing, each new race car was given a thorough workout on the test track at Weissach. As if that were not enough, it was customary for each new race car to survive a 1000 km assault on Weissach’s destruction track, which included a run through the pothole course, over humpbacks and the ramp which ensured that when the race car returned to the earth, any suspect components or manufacturing weak spot, would become immediately evident. Even the mighty Porsche 917 had to endure this punishing test, which was as mush a test for the car as it was for the drivers tasked with carrying out the test drive.
As a result, any race car that successfully completely this test regime, was very unlikely to fail on the race track. There were very few other manufacturers who could claim to have put their race cars through such a tortuous test. This, together with many thousands of kilometres of track testing around Paul Ricard, ensured that the 935 was immensely fast, ultra-reliable and as strong as a tank. It is perhaps therefore unsurprising that the 935 was so successful.
The 1977 season
While the 1976 season had been one of trials and testing various 935 components and setups, it didn’t stop Porsche winning both the World Championship of Makes as well as the World Sportscar Championship with the 935 that year.
For the first race of the ’77 season, the factory 935 was pretty much a 1976 car fitted with a single turbocharger. The Daytona 24 Hours was won by Hurley Haywood, John Graves and Dave Helmick in a 911 Carrera RSR, followed home by a pair of privateer 935s. At Mugello in March, a factory 935 was victorious, followed again by a pair of privateer 935s. The same pattern was repeated at the Silverstone 6 Hours in May, but the Nürburgring 1000 kms was almost embarrassing, depending on which camp your loyalties sat in. While the first two cars were indeed 935s, the top 19 finishers apart from third and 18th places which were filled by BMWs, the rest comprised Porsches consisting of a mix of 934s, 934/5s, Carrera RSRs and Carrera RSs.
At the Le Mans 24 Hours that year, a privately entered 935 finished third, while at the Watkins Glen 6 Hour, a factory 935/77 won followed by a Vasek Polak 935. At the Silverstone 6 Hours in September, the first four cars were again 935s. Hockenheim and Vallelunga rounded off the ’77 season with wins for the privateer Porsche 935s, little wonder that Porsche took the Marques’ Championship with 180 points to BMW’s 37 points.
The factory decided to withdraw from active participation in the championship at the end of the ’77 season, that is, apart from a brief but memorable assault with the famous ‘Moby Dick’ 935/78. That car wrote its own chapter in the history books, and even though the factory had withdrawn from officially competing, they did undertake to support the privateer teams who fielded the 935. But the purpose of this feature is not to examine the history and development of the Porsche 935, that would require a book, but this story instead charts the life and times of a specific 935, chassis #930 890 0021.
The 1978 season
One of the seventeen customer cars built in the production year 1978, chassis #930 890 0021, was sold through VW of America (VWoA) and Vasek Polak, to Interscope Racing to be driven by Danny Ongais. VWoA was the official Porsche importer in America, and an order for a race car would have been placed through an official distributor such as Vasek Polak. Interscope Racing was owned by media entrepreneur Ted Field, himself a very capable driver, and his main driver was Danny Ongais, one of the quickest drivers of his day.
Finished in the familiar all-black livery, Interscope Racing entered this car in two events in April ’78, its first event on 16 April was the Camel GT Challenge at Road Atlanta, round four of the IMSA GT Championship, with Danny Ongais behind the wheel. Having qualified eleventh, Ongais crossed the line in second place in the 100-mile event. In the second race that month, just two weeks later, Ongais put the car on pole for the Monterey Triple Crown 100-mile race at Laguna Seca Raceway. Unfortunately, the car retired in that race. Over the course of the 1978 IMSA GT Championship, this car was entered in five rounds, with Ted Field taking to the wheel for the final three, finishing fifth in two rounds and sixth in the final race.
The 1979 season
The first event of the 1979 season was the 24-Hour Pepsi Challenge, known to most as the Daytona 24 Hours. This was round one of the IMSA GT Championship with Ted Field, Danny Ongais and Milt Minter behind the wheel. Wearing race number 00, the 935 qualified in eleventh place, but before the race started, Preston Henn, who had practised in the Whittington brothers’ Porsche 934, purchased the Interscope car, immediately replacing Milt Minter in the cockpit. The car failed to finish due to an accident on the 29th lap. For the following event, the Sebring 12 Hours, Preston Henn was joined by Hurley Haywood and Peter Gregg, but despite placing the car second on the starting grid, it again failed to finish, completing 120 laps, half the distance of the winning car.
Owner, Preston Henn, was behind the wheel of #0021 in each of the remaining thirteen races, being joined by the likes of Bob Bondurant, Rick Mears, John O’Steen and Peter Gregg in some of the longer races. Henn’s best result was a fifth place overall which he secured in two races while driving alone, these being the Mosport Trans-Am and the Daytona Finale 250 Miles.
The Kremer Brothers race shop was a specialist Porsche tuning and preparation workshop operating out of Cologne, Germany. Brothers Erwin and Manfred Kremer formed a formidable team, with Erwin being a talented and successful driver while Manfred was the engine man.
Erwin’s first foray into racing was in a 356 B, this being followed by participation in the European Touring Car Championship driving a Porsche 911. Erwin Kremer claimed his first big title in 1968 with an overall win in the 24 Hours of Spa together with Willi Kauhsen and Helmut Kelleners. In 1970 Erwin got his first taste of the big time when he entered the Le Mans 24 Hours with Nicolas Koob, the pair finishing in a very credible seventh place overall, and first in the GT Class (2000-2500cc). Through the mid-70s the Kremers gained valuable experience on the track, and Kremer-prepared 911 Carrera RSR which was sponsored by Vaillant, Wally’s Jeans and Jägermeister formed a formidable trio and dominated much of the European GT scene.
In 1975, Erwin Kremer decided to withdraw from driving and to leave that to the professionals. Although he was a very accomplished driver Erwin ran a business from Monday to Friday, and raced on weekends whereas the professionals only competed. This change of focus allowed the Kremer racing organisation to experiment and develop new racing ideas with which to grow the company. 1976 saw the introduction of the factory 935 but this race car was only available for the factory squad, and so the Kremer Brothers built their own 935 K1. Complying with the 3.0-litre capacity limit, the single turbo 935 produced 650 bhp in 1976 (the 1974 3.0-litre RSR developed 330 bhp), while the 917 brakes made sure it was able to stop effectively from its 200 mph top speed. In 1977 they developed the K2, and the K3 was introduced at the start of the 1979 season.
It is safe to say that Kremer Racing’s biggest moment came at 16h00 on 10 June 1979, when the Cologne team accomplished what few ever dreamed of achieving. Victory in the most prestigious endurance race of them all, the 24 Hours of Le Mans, is usually reserved for the big-budget factory teams who can afford an army of mechanics and support crew, but the #41 Numero Reservé Kremer Racing K3 crossed the line that year a full seven laps ahead of the second placed car, another Porsche 935.
The success of this car in the 1979 Le Mans 24 Hours, with its lightweight fibreglass body (lengthened and widened) and lowered chassis, resulted in a flood of orders for K3 body kits from other privateer teams around the world. In addition, Kremer built thirteen K3s that were sold to other privateer teams, and so times for Kremer Racing were certainly good.
Apart from #0021 receiving K3 bodywork, Kremer made two important mechanical improvements. Firstly, the gearbox was turned upside down, which allowed the car to be lowered by approximately 40 mm. This modification also allowed the gear ratios to be changed without removing the engine. The second mod was the fitment of an air-to-air intercooler, which was not only lighter but it also gave a more even temperature drop across the air-cooled cylinders. This meant the K3’s engine could produce more power for longer, as it was cooled more efficiently. In period, these upgrades were rumoured to reduce intake temperatures by 40 degrees and increase power by 75 bhp!
The 1980 season
The car kept its black livery until the end of the ‘79 season, but for the start of the ‘80 season the car received its new Swap Shop colour scheme. In preparation for the first race, a Kremer K3 front end was fitted to the car but later in the season Chuck Gaa was tasked with updating the Henn 935 with a complete Kremer K3 type body. The new paint scheme on the car came from the fact that Preston Henn liked the Apple 935 livery, and he wanted something similar with the colour stripes along the car’s flanks. And of course, the car had to carry the Thunderbird logo, the name of Preston Henn’s swap shop in Fort Lauderdale, Florida, which is still there today.
The 1980 season got off to a good start when Al Holbert and John Paul Snr joined Henn to finish second in the Daytona 24 Hours (despite a broken oil line) and fourth in the Sebring 12 Hours. John Paul Snr notched up a third place finish at Laguna Seca, a first place with John Paul Jnr in the Lime Rock 400, and followed this up with a second place finish in the Daytona 250 Miles. In the final five races of the season, chassis #0021 retired twice, and finished fourth in two events and fifth in one. This brought to a close a season that on paper was a more successful one than had been the case in 1979.
The K3 carbon-Kevlar and Kevlar composite body was designed by Eckerhard Zimmerman’s company, Design Plastics, and the Kremer Racing team. The K3 featured fences around the tops of the wings to channel the airflow to where it was needed and to increase downforce. At the front, the number of ventilation slots above the front wheels had been substantially increased and only two driving lights were located behind Perspex covers in the front spoiler.
The side skirts, first seen on the 935/77, connected the front and rear wings to aid channelling of the airflow to both the dual brake cooling slots and air intake holes. The side skirts also helped seal the airflow on the underside of the car, again increasing downforce. Perhaps the most iconic K3 upgrade was the Kremer-designed rear spoiler, with supports which flowed smoothly from the rear pillars, giving the car a strong and purposeful look.
The 1981 season and beyond
The 1981 season was the car’s last competitive season, but it was one which didn’t bring #0021 good fortune, and the car finished well down in three races that year. Preston Henn traded the car with ANDIAL in 1982, for which he received #930 890 0013 in return. ANDIAL didn’t keep the car, and according to Alwin Springer, they sold the car to Monte Shelton in 1982 or 1983. From various records, Shelton retained the car for the next two decades, during which time he was regularly seen competing and displaying the car at a variety of events in America.
In 2006, the car was sold to Carlos Barbot of Portugal who returned the car to its original Interscope Racing livery of black with red stripes running up the fenders from front to back. The car received its FIA papers and was seen in various race events around Europe, including the Le Mans Classic. In 2016, the chassis #0021 changed hands again, this time entering a large historic race car collection in Europe, and was entered in the 2016 Spa Classic.
The car is being offered for sale, and interested parties can contact Davide De Giorgi of Girardo & Co at: [email protected] or +44 (0) 7890 896 612.
Thanks to Davide De Giorgi and Martin Raffauf for their help with this feature
Written by: Glen Smale
Images by: Girardo & Co, Porsche Werkfoto and Virtual Motorpix/Glen Smale