XLR-8 opened in 1984. It was manufactured by Arrow Dynamics (then called Arrow-Huss) and was the second suspended coaster built by Arrow, fixing the problems of the failed Bat at Kings Island.
For AstroWorld's Fright Fest 2002 event, the last four cars were reversed, which had never been done before on a suspended roller coaster. The name was also switched to 8-RLX. The change was successful and the trains remained like that until AstroWorld's closure in 2005, however the name was reverted after the Fright Fest.
AstroWorld closed permanently on October 30, 2005 following Six Flags' decision to sell the plot. On February 3, 2006 the ride was sold for $50,000 as scrap. The trains were sent to Six Flags Magic Mountain as spare parts for another Arrow suspended roller coaster, Ninja.
When XLR-8 opened, it had light blue track and white supports. At some point, it was repainted entirely dark blue. For the 2004 season, XLR-8 was repainted orange with turquoise supports.
2 trains with 7 cars per train. In each car, riders are arranged 2 across in 2 rows, for a total of 28 riders per train.