While there is less mud, the hill climbs that have been laid out will be quite technical, Harrison said.
"The ground's hard and dry, they'll be some good action.
"Whanganui always prepares a tough day."
It is a family affair for the Harrison's, as daughter Renee acts as his navigator, while son Blair will be navigator for Wellington's William Jeffrey, also Wanganui 4WD club members.
John McGonigle is another competing from the home club, while Palmerston North's Stuart Earle has local connections as he drives a truck built by the Turakina guru Dan Cowper.
Cowper is trying to add another national title to his resume, this one in C-Class, and has had finishes of first, third and fourth at the previous three rounds.
The action starts at 8.30am and will conclude around 4pm.
Harrison said in terms of distances for the fans walking around supporting the same teams, the course is reasonably compact.
"From one [viewing] area, you can see a lot."
Entry on Glencairn Rd is by cash only, with $20 for families, $10 for adults, and 5-12-year-olds $5.