"The FIA Group B regulations steered the concept towards a mid-engine, four-wheel drive layout, with a Jaguar V12 engine as the power source.[10][14] The concept car was designed and built at very little cost to Jaguar, as Randle called in favours from component suppliers and engineering companies he and Jaguar had worked with in the past. In return he offered public recognition for their assistance and dangled the possibility of future contracts from Jaguar.[7][10][11][14]
The name XJ220 was chosen as a continuation of the naming of the Jaguar XK120, which referred to the top speed of the model in miles per hour. The concept car had a targeted top speed of 220 mph (350 km/h) so became the XJ220.[9] The XK120, like the XJ220, was an aluminium-bodied sports car, and when launched was the fastest production car in the world.[15]
Engine and transmission[edit]
Jaguar and engine designer Walter Hassan had previously created a 48-valve variant of their V12 engine specifically for motorsport use. It featured a double overhead camshaft layout with four valves per cylinder, compared with the single overhead camshaft and two valves per cylinder of the production engine, which was used in the Jaguar XJ and Jaguar XJS models at the time.[10][11][16][17]
TWR and Cosworth had manufactured a number of these racing V12 engines during the 1980s and they had been raced competitively, with a 7-litre version of this engine featuring in the Le Mans winning Silk Cut Jaguar XJR-9. Five of these engines still existed, all of which were fitted with dry sump lubrication. These engines were chosen and considered to be especially useful as the dry sump would lower the vehicle's centre of gravity. The displacement of the V12 was set at 6.2 litres (6222 cc) for the XJ220.[17][18] The engine fitted to the XJ220 concept had titanium connecting rods.[10]
Jaguar had little experience with four-wheel drive systems at the time, having previously only produced rear-wheel drive cars. Randle approached Tony Rolt's company, FF Developments to design the transmission and four-wheel drive system for the XJ220, with Rolt's son Stuart running the project. Tony Rolt was the Technical Director of Ferguson Research, where he was heavily involved in the design of the four-wheel drive system used in the Jensen FF, the first sports car to be fitted with such a transmission.[19][20] Tony Rolt also had a long involvement with Jaguar, winning the 1953 24 Hours of Le Mans with the factory works team driving the Jaguar C-Type.[14][18][20]
The mid-engine complicated the design of the four-wheel drive system, and an innovative solution was needed to get drive from the rear of the engine to the front wheels. The chosen design took the front-wheel drive from the central differential on the rear transaxleand sent it through the V in the centre of the engine using a quill drive, before joining an inverted differential.[14] The clutch was a twin-plate unit designed by AP Racing.[11]
Bodywork and interior[edit]
The design brief for the exterior restricted the use of aerodynamic aids, and aimed for a stylish yet functional body similar to the Jaguar D-Type.[17] Drag and lift were limited at the envisioned ground clearance for road use, but the design allowed for additional downforce when the car was set up for racing; the body produced around 3,000 lb (1,400 kg) of downforce at 200 mph (320 km/h). The design was also intended to have a variable rear wing that folded into the bodywork at lower speeds.[17] Aerodynamic work was undertaken at the Motor Industry Research Association wind tunnel using a 1:4 scale model, as the project was unable to budget for a full-scale mock-up.[17]
The bodywork for the concept car displayed in 1988 was hand built from aluminium by Park Sheet Metal, a specialist automotive engineering company that manufactures concept cars and low-volume, niche models for various manufacturers, including Bentley. QCR Coatings undertook final painting of the bodyshell in silver.[21] The concept also featured electrically operated scissor doors and a transparent engine cover to show off the V12 engine.[10][17]
The concept car had a Connolly Leather-trimmed interior produced by Callow & Maddox, and was fitted with front and rear heated windscreens, electric windows, air conditioning, heated electrically adjustable seats with an Alpine Electronics CD player. The dashboard was supplied by Veglia.[10]
Chassis[edit]
The chassis was manufactured from aluminium using Alcan's bonded aluminium structure vehicle technology (ASVT), and had a wheelbase of 2845 mm.[10] The design for the chassis featured rear wheel steering and packaged the fuel tank behind the centre bulkhead.[22] Suspension design largely focused on road use, but a good compromise for racing use was achieved and the suspension height was adjustable.[22] The concept car was fitted with a four-channel anti-lock braking system.[10]
The concept car was larger than the production model at 5,140 mm (202 in) in length and 2,000 mm (79 in) wide. It weighed 1,560 kg (3,440 lb).[10]
Launch[edit]
The concept car was completed in the early hours of 18 October 1988, the day it was due to be unveiled at the British International Motor Show, being held at the National Exhibition Centre, Birmingham. The vehicle was completed at 03:00 GMT, moved to Jaguar's stand at 06:00 GMT and unveiled at 11:00 GMT.[23]
Jaguar's marketing department had allocated space on their stand at the motor show for the XJ220, but had not seen the vehicle until its arrival. Jaguar chairman John Egan and Roger Putnam, who was in charge of Jaguar's racing activities, were shown the vehicle the week before the motor show and signed off on the concept, allowing its unveiling.[24] The car received an overwhelmingly positive reception by public and press, and a number of wealthy Jaguar enthusiasts handed over blank cheques to secure a purchase option should the XJ220 concept go into production. Ferrari displayed their F40 model at the same event; an estimated 90,000 additional visitors came to see the Jaguar and Ferrari cars.[11][23]
The XJ220 was not initially intended to be a production car, but, following the reception of the concept and financial interest from serious buyers, a feasibility study was carried out by teams from TWR and Jaguar. Its conclusion was that such a car would be technically feasible (subject to engineering changes), and that it would be financially viable.[11][23] The announcement of a limited production run of 220 to 350 cars came on 20 December 1989. The list price on 1 January 1990 was £290,000 exclusive of value added tax, options and delivery charges, but by 1992 that had increased considerably owing to indexation of contracts. The offer was four times oversubscribed, and deposits of £50,000 exclusive of Value Added Tax (VAT) were taken from around 1400 customers; first deliveries were planned for mid-1992.[25]" https://en.wikipedia.org/wiki/Jaguar_XJ220#Concept_car
