The Porsche 935 K3

The Porsche 935’s period competition history was nothing short of astonishing. The twin-turbocharged monster in its myriad guises won over 150 races worldwide, with more than 20 further class victories. In addition to winning the 24 Hours of Le Mans outright in 1979, the 935 won the Daytona 24 Hours and 12 Hours of Sebring six times apiece. It was undefeated in the German Racing Championship between 1977 and 1978 and claimed three Nürburgring 1000km wins.

In winning the FIA’s World Championship for Makes four times in a row from 1976 to 1979, the Porsche 935 dominated endurance racing in a manner simply never seen before.

Intriguingly, it wasn’t only the Porsche factory which developed the 935 into the potent race-winning machine it became. A plethora of privateer outfits saw opportunities to enhance the 935, the most prominent and successful being the Kremer brothers in Germany. In 1976, Kremer developed the K1. The K2 followed in 1977 and the ultimate K3 appeared ahead of the 1979 season. The K3 famously went on to win Le Mans in 1979, with a factory specification 935 finishing second.

The American magazine Road & Track put a Martini-liveried Porsche 935 to the stopwatch in 1977, recording a 0–60mph time of 3.3sec, a 0–100mph time of 6.1sec, and the standing quarter-mile in a mere 8.9sec. For the era, these times were scarcely believable.

 

This Porsche 935 K3

This 935 was built by Porsche in 1978 and sold via Vasek Polak and VW of America to the Interscope Racing Team, owned by the American media mogul, entrepreneur and film producer Ted Field. Porsche built 24 twin-turbocharged 935s for its customers between 1978 and 1979.

Interscope Racing first entered this Porsche at the Camel GT Challenge at Road Atlanta, which was round four of the 1978 IMSA GT Championship. The car was driven by Danny Ongais who, having qualified 11th on the grid, finished second. Ongais stuck this 935 on pole position at the following round, the Monterey Triple Crown at Laguna Seca Raceway. This Porsche entered five rounds in that year’s IMSA GT Championship, with Ted Field taking to the wheel for the final three.

The first event in 1979 for this Porsche was the 24-Hour Pepsi Challenge, better known as the Daytona 24 Hours. Drivers Danny Ongais and Ted Field were joined by Milt Minter for the occasion, the trio qualifying 11th. Bizarrely, just before the race, Preston Henn, who’d practised for the race in the Whittington brothers’ Porsche 934, bought the car and immediately replaced Minter on the driver lineup.

Henn was an American powerboat racer and entrepreneur who’d founded the world-famous Fort Lauderdale Swap Show. He was an avid motorsport enthusiast and competitor, who actually claimed victory at Daytona in 1983.

To accommodate the CBS television schedule, the 1979 Daytona 24 Hours started at 16:23, with fewer than 90 minutes of racing before sunset. During the race, Henn had a big moment and slid across the grass opposite the pits. A bit shaken, he chose to return to the pits and retire the car.

A month later, the whole IMSA Championship reunited for the Coca-Cola Sebring 12 Hours, where Preston Henn entered this 935 with his team, Thunderbird Swap Shop. Henn employed the three-time Le Mans winner Hurley Haywood, who had also just won the Daytona 24 Hours, to drive alongside himself and Peter Gregg, although Gregg would only arrive on Saturday afternoon, as he was already competing in Atlanta at the IROC final! Haywood immediately showed his pace and qualified the car 2nd on the grid.

The race started at 11:00am, with Haywood chasing the leading 935, driven by Stommelen for the first 10 laps, with the pair quickly pulling away from the field. Haywood managed to overtake and lead the Sebring 12 Hours in this Porsche 935. Sadly, as the race progressed, the team experienced difficulties, and when Gregg finally arrived, he lost considerable time with a wheel-bearing replacement, before terminal gearbox issues. Over the remainder of the 1979 season, this 935 competed at a further 13 events, with Preston Henn largely behind the wheel, regularly finishing inside the top 10. Once the season ended, this 935 was entrusted to Chuck Gaa, of GAACO in Atlanta, Georgia, who upgraded it to Kramer Type 3 ‘K3’ specification.

In Germany, the Kremer brothers had been developing several variants of the Porsche 935 to be even faster, with the most successful version being the third, the K3. The easiest place to spot improvements was to the exterior, where a carbon-Kevlar and Kevlar composite body was fitted, being 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 seen behind Perspex covers in the front spoiler. The side skirts, first seen on the 935/77, connected the front and rear wings to aid channeling 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 rear spoiler, of Kremer design, with supports which flowed nicely from the rear pillars. There were also improvements to the design and fitment of the roll cage, resulting in improved handling.

Mechanically, Kremer made two important improvements. One, they turned the gearbox upside down, which allowed the car to be lowered roughly 40mm, whilst also allowed the gear ratios to be changed without removing the engine. The second was the fitment of an air-to-air intercooler, which was not only lighter but also gave a more even temperature drop across the air-cooled cylinders, meaning the K3’s engine could produce more power for longer, as it was being cooled more efficiently. In period, these upgrades were rumoured to reduce intake temperatures by 40 degrees and increase power by 75bhp! The Kremer Racing Team made several cars themselves, but also offered a kit which allowed a standard factory Porsche 935 to be upgraded to K3 specification.