During 1996, Automobili Lamborghini SpA contacted SAT in France to design and build a race version of the Diablo to be able to compete in the GT championships, much like the Porsche GT1 from 1997, this was a car that needed to be based on a production car, but with a completely race oriented setup.
SAT, Signes Advanced Technology, is a company based in Toulon, France which is specialized in the design and construction of prototypes and race cars, they were contracted to design and build what would become the Diablo GT1, while Automobili Lamborghini SpA would supply a custom V12 engine and get the entire project through homologation.
A special 6-Liter engine was created with an enlarged stroke, later another evolution of this engine would be used in the Diablo GT and the VT 6.0 production model. By using a reprogrammed injection system this engine reached 655 Bhp driving the massive 18 inch rear wheels only.
At first the Diablo GT1 was shown with Michelin tires, but later these were replaced with racing slicks made by Dunlop, note that only two GT1’s were ever built, chassis numbers VLA12001 and WLA12000, the first one was sold to the JLOC in Japan and they have been using it to compete in the Japanese GTC ever since 1997. The second Diablo GT1 was finished in bright yellow and remained the property of SAT, were it was being displayed at their factory.
As usual with special GT cars the bodywork was heavily redesigned and only looked slightly like the original Diablo, a brand new, very deep front chin spoiler and the obvious adjustable rear wing were mounted. The front spoiler also housed a large oil cooler with a central air intake, the front turn signals were still used, however the pop up headlights were replaced by air intakes and small poly-ellipsoid lights covered with Plexiglas.
From the 1998 season on, the Japanese Diablo GT1 received small fins at both sides of the front bumper to increase down force. Also the front hood now incorporated air extractors to allow the air to pass through the front mounted oil cooler, the side windows were replaced by Plexiglas units and used a small sliding part and three air outlets were cut into the rear part of the window.
The entire rear section of the Diablo GT1 could be removed to allow easy access to the massive V12 engine, this engine received two air intakes just behind the roof section to draw cool air inside, special outlets were built into the rear cover to allow an air current through the compartment with the bodywork in place.
The entire suspension geometry and chassis was modified by SAT to comply with racing regulations, also the body panels were made by SAT themselves, in ultra-light carbon fiber naturally, note that the upswing opening doors were still used on the Diablo GT1.
The project was finalized and presented to the factory in April 1997 while both the Italian Ministry of Transport and the Federation International de l’Automobile confirmed homologation in 1998, unfortunately Chrysler didn’t went forward with the Diablo GT1 idea and after Audi AG bought the factory, the Diablo GT and GTR were developed, the special GTC series were abandoned.