Lamborghini began developing the Diablo (which translates to "Devil" in Spanish) in 1985 as a replacement for the Countach model, introducing it for sale on January 21, 1990 at a base price of USD 240,000. Power came from a 5.7-litre, 48-valve version of the legendary Lamborghini V12 featuring dual overhead cams and computer-controlled multi-point fuel injection, producing a maximum output of and of torque. The vehicle could reach in slightly over 4 seconds, with a top speed of . The Diablo was originally rear-wheel drive and the engine was mid-mounted to aid its weight balance.
Even at over $240,000, the vehicle was somewhat spartan, featuring only basic radio functions (with optional CD playback) along with manual windows, adjustable but unpowered seats and no anti-lock brakes, mostly to minimize the vehicle's already high curb weight. A few options were available, including having the driver's seat molded specifically for the buyer, a rear spoiler, a factory fitted luggage set (priced at $2,600) and an exclusive Breguet clock for the dash (priced at $10,500).
After three years of making minor adjustments to the Diablo, Lamborghini decided in 1993 that a second, even more specialized version of the car could add new customers to the brand. Starting with the basic Diablo platform, Lamborghini engineers added a viscous-coupling type all-wheel-drive system, an improved power steering system, resized front wheels and tires chosen to work better with the all-wheel-drive system, four-piston Brembo brake calipers, an updated dashboard design and a new computerized suspension system featuring aggressively tuned Koni shock absorbers. The suspension system could be left in "auto" mode where it was controlled entirely by the computer, or any of four separate "modes" could be manually selected by the driver via buttons in the cabin. The vehicle still lacked ABS brakes. Lamborghini had presented an open-topped concept version of the VT (Viscous Traction) at the 1992 Geneva Auto Show alongside the coupé when the car debuted there, but it was another 3 years before the model saw production. Other than its removable Targa-style carbon fiber roof panel, the vehicle was essentially identical to the coupé, with only a few minor styling differences, mainly in regards to the tail lights between the two models.
In order to bring additional publicity to their pro-am series in 1997, there was a roadster version of the SVR, called VT Roadster R, despite being based on an SVR chassis with everything that its racecar variant has and lacking the four wheel drive system of the VT.
A lightened, hard-edged racing variant of the standard Diablo, the SE30 was sold in limited numbers during 1994 to celebrate Lamborghini's 30th anniversary. The 'SE' stands for Special Edition.
In total just 150 cars were made, eight of which were right hand drive (RHD). In 1995 Lamborghini introduced the SE30 Jota; the Jota was produced from the Lamborghini factory but SE30 owners also had the option of having Lamborghini upgrade their SE30 to Jota specifications. The Jota upgrade consisted of two roof mounted air scoops, a re-tuned L.I.E. chip and a six-speed all-synchromesh gearbox if the Diablo was made at the Lamborghini factory. With these upgrades in place the Diablo SE30 Jota could produce 595 bhp, 72 more than the SE30's . In total only 28 Jota upgrade kits were made but 1 of these was not installed. Contradictory to this, it is believed that only 12 Jotas were actually made (10 in LHD, 2 in RHD); this figure may have come from the number of models made by Lamborghini itself. As an interesting side note about the Jota, Jay Kay (lead singer of Jamiroquai), featured the sound of this car in the intro to a track, called "Travelling without moving" on the band's album of the same name.
The car went without most of the Diablo's standard equipment, meaning that it was devoid of a radio, air-conditioning or sound insulation and featured carbon fiber molded seats, helping to make it lighter than the standard car. Lamborghini chose to do without the VT's advanced electronic suspension or all-wheel-drive systems, but the car did get an advanced adjustment system controlled with an interior dial that could instantaneously adjust the stiffness of the car's front and rear anti-roll bars. They also enlarged the brake discs of all four wheels, but the car still lacked ABS.
The SV or "Sport Veloce" variant of the Diablo was an optional add-on package to the base car. It lacked the VT's all-wheel-drive system and electronic suspension, but it featured the VT's revised dashboard and larger brakes, a new 3-piece adjustable spoiler and was powered by a modified version of the 5.7-litre V12 producing . The car's air intakes were slightly differently shaped, and from 1999 onwards the vehicle had exposed headlamps as opposed to the pop-up units previous versions used.
Tuning company Koenig-Specials of Germany produced a tuned variant of the SV featuring further suspension modifications, massive brakes and a twin-turbocharger system, boosting the car's output to over .
The SVR is less than the SV and boasts , mainly of a revised fuel injection timing and is the first Diablo to use variable valve timing. There are numerous noticeable cosmetic differences, the covered lights are sometimes used in place of its usual retractable headlights. Other cosmetic differences includes, a deeper front spoiler, side skirts and a redesigned rear valance. Also the most visible modification is a fully adjustable rear aerofoil, lightweight acrylic side windows are used in place of a glass items and a set of 18-inch OZ Racing one-piece hollow spoke cast magnesium wheels Each car sold came with a seasons factory support and an entry to the one-make series. All repairs and maintenance were carried out by Lamborghini themselves.
The series first title winner was BPR regular, Thomas Bscher, who became involved with the business side of the brand in later years. In total, 31 versions of this model have been produced altogether. Only a few of these have been modified for road use.
Otherwise, the 1999 Diablo remained fundamentally unchanged. Like the updated VT, it was produced only as a production model for the 1999 model year. A limited edition 2000 model was produced, available only in metallic silver - most of these cars are in the United States.
As much as the SV (Sport Veloce) was already a near race-ready version of the Diablo, the limited run GT model went even further in the same direction. It boasted a modified version of the V12 engine, bored out to 6.0 litres and producing , while enlarged brakes, an improved and lower-riding suspension and owner- ygnacio lamborghini changes. More aggressive bodywork with flared fenders and wider wheels were introduced. Only 80 units were produced in total and the vehicle was only officially sold in Europe.
The engine management system is based on the proprietary Lamborghini LIE electronic engine control system tuned for racing. Fuel injection is sequential multipoint and ignition is static with individual coils. Lamborghini Data Acquisition System, LDAS, and diagnostic functions are integrated in the engine electronic management system.
For the engine cooling, two water radiators in parallel are side mounted to the engine and an engine oil cooler is front mounted as in the Diablo GT. Additional coolers for gearbox and differential oil are installed in order to better match the racing overloads.
The transmission is on the rear wheels through a Lamborghini 5 speed gearbox with one basic gear ratio option and an alternative option for a shorter 5th gear ratio. The gear box lever is in an asymmetric position on the central tunnel in order to be closer to the steering wheel, for better control. The steering system is power assisted.
The tubular chassis frame integrates the roll bar and is directly connected to the rear wing. The front suspension is modified for racing. Shock absorbers and anti-roll bars are adjustable. The rims are lightweight magnesium alloy with central fixing nut and they accept racing type tyres. A special racing fuel tank with fast filling system has been installed. The braking system is based on the Diablo GT high performance module. New racing brake calipers have been adopted to better match the very severe racing conditions.
Most of the body is carbon fibre made, except for the roof, which is made of steel for torsional rigidity, while the doors are made of aluminium, for safety reasons.
The cockpit fittings are simplified to meet racing requirements. The driver seat has been moved towards the longitudinal axle of the car, reducing the size of the central tunnel, to ensure a better driving position. Racing switches for ignition and for other functions have been adopted instead of the series push buttons. The fire extinguisher system is installed on the right side of the cockpit with activating switch on the tunnel. The driver's seat is of racing type with a six-point safety belt and the steering wheel is also racing type.
A production run of 30 cars was planned at the launch of the car at the 1999 Bologna Motorshow, but at the end of the run 40 cars were built.