suitable for sports car racing. As the V64V was originally naturally aspirated, it was necessary to redesign all parts of the engine to accommodate forced induction. A few of the changes included increasing the displacement to 3.5 litres, strengthening the internals and adding two Garrett TO3 turbochargers. The JV6 engine would first be used in the JaguarSport XJR-10 and XJR-11 racing cars; its compact dimensions and low weight made it an ideal candidate for the XJ220. The engine had a 90° bank angle, four valves per cylinder and belt-driven double overhead camshafts. The V64V engine chosen had a short but successful career as a purpose-designed racing car engine. It was designed by Cosworth engine designer David Wood for Austin Rover Group's Metro derived Group B rally car, the MG Metro 6R4. The redesign work necessary to create the Jaguar/TWR JV6 engine was undertaken by Andrew Barnes, TWR's Powertrain Manager, and also involved Swiss engine builder Max Heidegger, who had designed and built the race engines used in the XJR-10 and XJR-11 racing cars. The XJ220's engine had a bore x stroke of , dry sump lubrication, multi point fuel injection with dual injectors and Zytek electronic engine management. The engine was manufactured with an aluminium cylinder block and aluminium cylinder heads with steel connecting rods and crankshaft. In the standard state of tune, it was rated at a power output of at 7,200 rpm and torque of at 4,500 rpm. The XJ220 could accelerate from 0– in 3.6 seconds and could attain a top speed of . Road & Track tested a top speed of , 0– acceleration in 4.8 seconds and 12.4 seconds for the standing . The XJ220's exhaust system consists of two catalytic converters, which reduce the power output of the engine. During testing at the Nardò Ring in Italy, one XJ220 had its catalytic converters removed and its rev limit increased to 7,900 rpm; these modifications increased the car's power output by and the car was then driven by 1990 Le Mans Winner Martin Brundle to a top speed of . Owing to the circular nature of the track, some (including the British car magazines Top Gear and Autocar) say a speed of is equivalent to on a straight, level road. However, on other tracks it performed differently; when top speed was tested on a straight level road by Road & Track it only amounted to