[Purist]

It's a matter of connotation. Touring Cars, nowadays, generally means racing what are econoboxes in road-going form. Those cars themselves just don't excite me much, if at all.

GTs have started life as high-performance cars that run on the road, and are hotted-up from there.

As for the Sportscar/GT/Prototype thing, I think they were more or less interchangeable up through 1953 or so. I think Prototype Sportscars really began to separate themselves from GTs in 1954-55, with the arrival of the Jaguar D-Type, Mercedes-Benz 300SLR, Ferrari 410S, and Lancia D25.

GTs are road-going Grand Tourers and Sports Cars modified for racing. The main difference in road-going form for me is the car's handling. As an example, a Bugatti Veyron has 1,000hp, and an insane top-end speed, but there are other supercars with only 550-700hp that will beat it on the road course. The Bugatti Veyron is a Grand Tourer, while a McLaren F1 is a Sports Car. And a car like the Ferrari 599 GTO kind of straddles the line between the two in road-going terms.

A GT is a GT, and a TC is a TC. If a series is all production-based, then it's a GT, a GT/TC, or a TC series.

If they're using silhouettes, then it's a Silhouette GT series or a Silhouette Car series, depending on whether they're meant to look like GTs and production Sports Cars (Group 6, SCCA GT1), or they're meant to look like Sedans/Sedan Coupes (DTM, V8 Supercars, NASCAR).

Japan SuperGT is just all over the place with Silhouette GTs (ASL Garaiya, Nissan GT-R), actual GTs (FIA GT3s), and Silhouette TCs (Toyota Corolla Axio, Lexus SC430). I call it a GT series, because anything else would just be too complicated.

And as a direct response, I would say that the Spa 24 is a GT race. The CTSCC is a GT/TC series, though probably more TCs in the mix than GTs.