The XJR-17 was a converted XJR-16, it used a NA version of the V6, aimed at the FIA Cup and IMSA Lights.
It competed in club events, and more recently, Group C/GTP, it's since been converted back to XJR-16 spec.
http://www.motorsport-fanatic.co.uk/...GT-jaguar.html
Cat 2 = Old Group C cars
Cat 1 = 3.5l