Jaguar XJ220

The Jaguar XJ220

When the Jaguar XJ220 appeared as a last minute entry at the 1988 Motor Show it stunned the crowds. Few people believed it could be put into production, but Jaguar confounded their critics and built, what was at the time, the world’s fastest road car – a status that remained until the advent of the McLaren F1 in 1994.

XJ220 - The Prototype

In the best traditions of Jaguar, and like the XJ13 before it, the XJ220 was conceived by “The Saturday Club” – an informal group of Jaguar employees who would meet after-hours and on weekends to work on unofficial projects.

Ex head of product development, Jim Randle’s vision was of a car powered by detuned version of the Le Mans winning XJR-9 V12 engine, together with a full complement of technology to provide an immensely capable road car: four-wheel drive, anti-lock brakes, and the potential for traction control, adaptive suspension and four-wheel steering.

It was this prototype that made a last-minute debut at the NEC in October 1988. Already very nearly a fully working vehicle, it was still very much a one-off. However Sir John Egan hinted, as he unveiled the prototype, that it could indeed become a production car.

From Prototype to Production

To develop the prototype into a full production model, Jaguar turned to Tom Walkinshaw, head of Tom Walkinshaw Racing (TWR) and JaguarSport, who had had success that year at the Le Mans 24-Hour with the XJR-9LM.

Tom Walkinshaw reported back that the XJ220 could indeed be produced, and could also make a decent return on the investment required, but not as it stood. A new car needed to be designed, keeping to the original shape but using a twin-turbo V6 and rear-wheel drive to produce a shorter, lighter vehicle owing more to Jaguar’s racing experience.

It couldn’t be V12, four-wheel drive and have everything on it. A not inconsiderable problem was getting tyres to last under the car; we had to get the weight down even to do that. We evolved a specification and came back with a V6 car, much smaller, much shorter but retaining most of the styling cues from the original concept car.

The benefits we got from the four-wheel drive system were so small with this type of vehicle that they didn’t warrant the complexity, weight and cost. Because the car has many new features, like ground effects, then the traction it enjoys is far superior to a conventional car and you can get as much control on your braking conventionally as you would with ABS.

Tom Walkinshaw

As for the V12 engine, its size and weight ruled it out. Not only that, but to achieve the target of 500bhp and keep the engine’s emissions within the regulatory bounds for a road car would have proved impossible. At the time Jaguar’s Group C race cars had just changed over from the V12 to TWR’s own twin-turbo V6 for similar reasons, and a 3.5-litre road going version of these would certainly deliver the required performance.

The styling dictated that the V6 be used; a very short engine was necessary because of the wheelbase that had been selected – a ‘V’ engine was about the only thing that you could actually package in the space.

Tom Walkinshaw

On 14 December 1989, it was announced that between 220 and 350 XJ220s would be built, at a price of £290,000, index-linked to delivery date. The response was overwhelming and only 48 hours after the announcement JaguarSport had orders for several times the maximum number of cars they were prepared to build.

In May 1991, the car passed its crash test with flying colours first time – rearward displacement of the steering wheel was only 13mm and all the glazing stayed in place and the doors still opened normally, even the headlights and front tyres survived. For the roll-over simulation test pressure was exerted on the roof to test that the car could withstand the required level of 1.5 times the vehicle’s body weight – over 2000kg for the XJ220. The test was discontinued at a downward pressure of 10 tons with no body deformation. Not even the windscreen was cracked.

In May the first production prototype was built and the XJ220 ran for the first time on 1 June.

The main development then switched to achieving the cars projected performance. Keeping engine temperatures down to acceptable levels meant adding a pair of air vents to the rear quarter-panel. Aerodynamic tests on the car’s 1/5th scale model in Imperial College’s moving-floor wind tunnel came out very close to projections. According to chief designer Richard Owen, the twin underbody venturis made the XJ220 the first road car in the world to generate true ground effects. A downforce of over 600 lb was generated at 200 mph, pressing the car onto the road and helping to maintain stability at speed.

During testing, thousands of miles were covered at high speed tracks like the Nurburgring, Nardo in Italy, and Ford’s Fort Stockton circuit in the USA, where the car established an average speed of 208 mph and a maximum of 212 mph in July 1991, making it the fastest road car in the world. Later, Martin Brundle tested the car at Nardo and, after removing the catalytic converters which robbed the engine of approximately 60 bhp, achieved 217.1 mph – the equivalent of 223 mph on a straight road.

Jaguar XJ220 at Painshill Park
Rear view of the prototype XJ220
XJ220 twin turbo 3.5-litre V6