Why was it OK to make such a radical change of series DNA as banning a fleet of turbocharged Sierras, Skylines, Starions, Supras and others that competitors, sponsors and manufacturers had spent good money on?
Did the same arguments that apply now, of protecting sunk costs into a fleet of pushrod V8 racing engines, not apply then to a fleet of Cosworth engines, RB26 engines and similar!?