Porsche originally needed to produce the car in order to comply with homologation regulations and had intended on marketing it as a street legal race vehicle like the 1973 Carrera 2.7 RS.
For the 1976 season, new FIA regulations required manufacturers to produce 400 cars within a twenty-four-month period to gain approval for Group 4.
While the original purpose of the 911 Turbo was to gain homologation for the 1976 racing season, it quickly became popular among car enthusiasts.
[6] Ernst Fuhrmann adapted the turbo-technology originally developed for the 917/30 CAN-AM car and applied it to the 3.0 litre flat-six used in Carrera RS 3.0, thus creating what Porsche internally dubbed as the 930.
The 930 proved very fast but also very demanding to drive, and due to its short wheelbase and rear engine layout, was prone to oversteer and turbo-lag.
[citation needed] Porsche made its first and most significant changes to the 930 for 1978 model year, enlarging the engine bore by 2 mm (0.08 in) to a total displacement of 3,299 cc (3.3 L; 201.3 cu in) and adding an air-to-air intercooler.
With the so-called Werksleistungssteigerung (WLS, "Works Performance Increase") add-on came a quad-pipe exhaust system and an additional oil-cooler requiring a remodelled front spoiler and units bearing the add-on often featured additional ventilation holes in the rear fenders and modified rockers.
[10] In 1982, TAG Heuer co-owner Mansour Ojjeh commissioned Porsche to develop a road-legal version of the 935 race car.
The Flachbau units delivered in Europe usually featured the 330 PS (243 kW; 325 hp) WLS performance kit.
The flat nose greatly contributed to the aerodynamics of the car and enabled it to accelerate from 0–97 km/h in 4.85 seconds and attain a top speed of 278 km/h (173 mph) (figures with the performance kit).
The engine was given the code TTE P01 and was fitted in the McLaren MP4/2 and MP4/3 generating 760–1,014 PS (559–746 kW; 750–1,000 hp) depending on track conditions.
The changes to the interior consisted of racing bucket seats and a new TAG branded tachometer with a 10,000 rpm redline.
In September 2018, English automotive company Lanzante introduced a new model based on the same principle at the RennSport Reunion VI.
The company obtained permission from McLaren to produce the model and bought 11 of those engines originally installed in the F1 cars for this purpose from the manufacturer.