Capacity was reduced to 2.85 L, and with the turbo charging penalty factor of 1.4, it fit into the 4.0 L class which had a prescribed minimum weight of only 970 kg (2,140 lb).

The air-to-air intercooler setup under the rear hood had to be altered to a more compact air-to-water layout, which cost Porsche several weeks of testing and half a million Deutsche marks.

[7] The hastily modified 935 again won the pole and fastest lap at the six-hour Silverstone, but due to a clutch problem at the start, the Martini car could finish only tenth,[8] with the second-placed Kremer 935 collecting valuable points for Zuffenhausen.

However, after carefully studying the rulebooks, Porsche engineers, namely Norbert Singer, discovered a loophole regarding the modifications of fenders that gave them the liberty to remove the headlights to reduce drag and create more downforce, to which the venting slits contribute.

Also, the 935 now had extended "long tail" rear fenders, similar to the low drag setup seen years earlier on the Carrera RS.

Again, a reliable Schnitzer Motorsport-entered naturally aspirated BMW CSL took the win, with the customer 934 of Loos salvaging valuable second place points for Porsche.

In Dijon, the turbo of BMW Motorsport was back, now with the 3.5 L CSL, and this time the fast Swedes Peterson and Nilsson put it on the pole, half a second ahead of Ickx.

I (over 2.0 litre) of the DRM, these Porsches had no serious competition in the big division until other turbo-charged cars like the BMW-powered Schnitzer, Toyota Celica and the Zakspeed Ford Capri debuted.

In the 1977 World Championship for Makes season, the factory continued to develop and race one or two new 935, in case BMW or another brand would bring a competitive turbocharged car.

Customers of the 935/77A were not happy that the factory would race them with a newer car, but as the 935/77 was often unreliable, it won only four of the nine WCM events, which did not include Le Mans.

In the WCM season opening 24 hour Daytona, the old car was entered, but tyre failures caused a DNF, with an older RSR 3.0 taking the win in front of two customer 935's.

This improved throttle response and also power, but several head gasket failures meant that Porsche had some homework to do for the1978 season of the World Champion chip of Makes(WCM).

Skipping the Diepholz airfield round, Porsche sorted the car out for the DRM support race[20][21] of the 1977 German Grand Prix at the fast Hockenheimring (long version).

Unlike the factory 935/77 which had a center monocoque with front and rear tubular frames, Lundgardh constructed an entire spaceframe chassis, which was more akin to the setup found on the 935/78 "Moby Dick".

[22][23] The windshield was borrowed from a 911 Turbo, and retained much of the body of a factory 935, however towards the end of its debut season in 1980, it was eventually fitted with bodywork from the K3 developed by Kremer.

[22] Reliability problems plagued the car throughout its earlier seasons, Le Mans proving no exception as the L1 retired in the 5th hour with engine failure.

As this track, like most, was run clockwise, the driver seat was moved over to the right side for better weight distribution and sight in right-hand corners, like Dunlop, Tertre Rouge and Mulsanne, another distinctive feature of the 1978 model.

With this version, the pair of Mass/Ickx won the test race, the 6 hours of Silverstone Circuit, the pole (1:22,38) and fastest lap (1:23,98 or 202,519 km/h), being only 4 seconds slower than the corresponding times of James Hunt in the 1977 British Grand Prix, which covered only a quarter of the distance.

Awaiting rule changes taking effect in 1982, Porsche did not officially enter in 1979 or 1980, granting only some limited support to customer efforts with the 935, 936 and even decade-old 908 and 917, mainly in form of spare parts, engines and know-how, which by then was rather dated.

[citation needed] As Porsche hesitated to sell their Evolution models, some teams developed their own ideas, especially Kremer Racing from Cologne, Germany.

Driven mainly by Klaus Ludwig, it won the 24 Hours of Le Mans in 1979, beating all prototypes, in heavy rain, which is usually considered a disadvantage for race cars with windshields.

Coming in second was a factory spec model, driven by Rolf Stommelen, and supported by team owner Dick Barbour and actor Paul Newman.

Facing strong competition in the 1980 DRM by the Zakspeed Ford Capri, the K4[26] was introduced in mid 1981 for customers at a cost of 400,000 Deutsche Mark.

[27] The K4 used a Porsche supplied 3.1 L twin-turbocharged Flat six engine with a varying power output of 559 to 596 kW (760 to 810 PS; 750 to 799 hp) at 1.5 bar boost costing 91,000 DM.

The 1983 Australian GT Championship was won by the same 935 which Jones drove to the 1982 title, this time in the hands of touring car driver Rusty French.

As a reward for his win in the 1983 championship, French was given a drive with Kremer Racing at the 1984 24 Hours of Le Mans where he finished 9th outright with Tiff Needell and David Sutherland in a 956.

Starting in 1999, this engine block forms the basis of the successful motorsport GT, and Turbo models before being phased out completely in the 991 generation 911.

By 1985 the days of the 935 were mostly over, as it could hardly be modified to a groundeffect design even with a tube frame chassis, with the rear-mounted flat 6 prohibiting a diffuser, an issue which also affects modern 911 race cars.

The 1990s 911 GT2 based on the 993 is also considered a successor to the 935, but BPR series and FIA GT rules required a higher weight, and intake restrictors limited power to 410 kW (557 PS; 550 hp), less than the first 935/76.

Starting in 2003, the turbo-charged Porsche 996 of Alzen set new records at the Nürburgring VLN endurance series (see List of Nordschleife lap times (racing)), with speeds reminding of the 935 era, despite it being also slowed down by minimum weight (1,350 kg) and limited boost.