From Halopedia, the Halo wiki
In Warzone Turbo, players automatically reach level energy after securing their Home Base. They obtain full access to their REQ inventory, with energy recharging significantly faster than usual, thus enabling the use of a myriad of REQ cards throughout the game. It is conceptually a mix of Fiesta and BTB Heavies.
Warzone Turbo supports all the maps supported by standard Warzone.
Originally the gametype was not intended for inclusion in matchmaking, as it was created for playtesting so that developers could efficiently test Warzone's features at any time during the game. However the developers decided to include it temporarily after recognizing it was an interesting concept. The weekend playlist "Weekend Warzone Turbo" has been added to matchmaking several times, usually around the release of a new content update.