One of the biggest improvements for spectators will be the introduction of a live, F1-style pit lane, with teams choosing whether or not to pit after each lap.
Five classes of vehicle will be competing – Ultra4, Legend, Modified, Stock and UTV – and all vehicles will race on the same course, apart from a couple of bypasses for the Stock and UTV racers.
The specially-designed course is 15km (9.5 miles) long, and each vehicle must run repeated laps until it has completed 120-165km (75-103 miles) depending on class. That’s more off-road miles than ever.
Among the highlights will be the newly created Maxxis Bowl, in the old quarry, 'Valley Town' (the main pit area), and the Odyssey Battery Arena with obstacles such as 'Valley's Revenge', Dragon's Tail' and 'Belly Basher'.
Transport will be arranged for spectators aroudn the site.
For 2015 the event has been renamed from ‘King of the Valleys’ to ‘King of Wales’.
King Shocks will be running a tuning day on Thursday 6, with the experts on hand to advise. Qualifying is on Friday 7, followed by dinner for the competitors, with a welcome speech by Dave Cole, Ultra4 President.
The main action starts on Saturday 8 at 09:00, with the fastest setting off and racing side by side. The course will be live until closing at 18:00. Saturday night sees the Wilderness Lighting night stage starting at 22:00, promising side-by-side action in the dark.
Sunday runs from 08:00 - 16:00, followed by the prize giving ceremony and the crowning of the ‘King’ at 18:00.