TWR Jaguar cars won the WSCC outright in 1987, 1988 and 1991 and won the prestigious 24 Hours of Le Mans and the 24 Hours of Daytona in 1988 and 1990. The series started in 1985 with XJR-6 (Group 44 used the XJR-5 and XJR-7), designed by Tony Southgate, with a chassis built from carbon-fibre and power provided by a highly tuned Jaguar V12 engine. This was followed by XJR-8, which won the WSCC Team's Championship in 1987, then XJR-9 which won the WSCC Team's Championship in 1988 and also secured victory at Le Mans the same year, returning in much the same form as the XJR-12 to win Le Mans again in 1990. TWR developed its own engine for the next series of cars, the XJR-10 (for IMSA) and XJR-11 (for WSCC) of 1989 and 1990, employing a 3.5 litre twin-turbocharged V6, which was capable of far more power than the V12 but was less suited to 24 hour racing (hence the XJR-12 being deployed at Le Mans and the 24 hours of Daytona).