The 1998 United States Road Racing Championship season was the inaugural season of the revived United States Road Racing Championship run by the Sports Car Club of America (SCCA). The season involved four classes: Can-Am prototypes and three Grand Touring classes referred to at GT1, GT2, and GT3. Five races were run from January 31, 1998 to August 23, 1998. Taken from http://en.wikipedia.org/wiki/1998_United_States_Road_Racing_Championship_season.


The 1998 Professional SportsCar Racing Championship season was the 28th and final season of the IMSA GT Championship. It consisted of an open-cockpit World Sports Car (WSC) class of prototypes and Grand Tourer-style racing cars divided into GT1, GT2, and GT3 classes. It began March 22, 1998 and ended October 25, 1998 after eight rounds.
The IMSA GT Championship was replaced by the American Le Mans Series in 1999, which was supported by the Automobile Club de l'Ouest (ACO). This series, based on the 24 Hours of Le Mans, was initially previewed during the 1998 season with the running of the inaugural Petit Le Mans. Professional SportsCar Racing remained as the series organizer.
Of note is the lack of the 24 Hours of Daytona and the Six Hours of Watkins Glen, both of which were acquired by the revived SCCA United States Road Racing Championship. Taken from http://en.wikipedia.org/wiki/1998_IMSA_GT_Championship_season.