the Turbo 1 was the original race car with a few cars built for the road so the race car could be homologated for competition.
the Turbo 2 was more of a std made for the road car utilising a lot more production parts rather than lightweight special components.
the Maxi Turbo was the final variant of the car but this time built for competition, it had bigger arches etc & a slightly bigger engine (1500cc i think??) that ran a lot more boost & made up to 350 - 400BHP
apparently it was the best handling 2wd tarmac rally car ever made!
ever according to some!