From the Motor Sport Archive
The first race in the 1966 Manufacturers G.T. Championship was held on the road/track circuit at Daytona Beach in Florida. This year's Continental had been extended to a full 24-hour race with a line-up of 60 cars. The circuit makes use of all but a few yards of the banked stock car track with 1.3 miles of artificial infield flat turns giving a total length of 3.81 miles. Two of the three banked turns are 31deg.and capable of speeds up to 170 m.p.h. while the shallower banked turn in front of the pits is a much flatter curve.
With a fair-cum-circus behind the main grandstand this race was a copy of the Le Mans 24-hour race but unlike Le Mans, which has about six hours of darkness, this race had a full 12 hours of night driving. Practice periods were from 1 p.m. to 5 p.m. and 7 p.m. to 9 p.m. on both Wednesday and Thursday, with no time-keeping. On Friday practice and timing went on from 9 a.m. until 5 p.m.