Max, who goes by his full name of Maximus on the track, was in action in Wellington last weekend in a "dress rehearsal" for the nationals, Rennie said.
That didn't go quite to plan, and the kart needed some repairs this week.
"There was a big crash, which wasn't his fault.
"Someone spun in front of him and it was unavoidable. He had a bit of a sore thumb but nothing major.
"Up the straight they are doing anywhere up to 90km/h. It's quick."
Max said it was the high speeds he enjoyed the most, and a career in motorsport was definitely something he wanted to pursue.
"This year I'm hoping to get at least top 20."
He will be racing in kart 63, which is also the number of his favourite driver, Formula 1's George Russell.
Rennie said one of Max's goals was to eventually move up from the Vortex Mini ROK class to Rotax, which was the biggest in the world.
Mother Tina Drayton said her son had been hooked on the sport since having a go at a trial day in Palmerston North.
"They give you a go-kart for the day and all the kit, like fireproof suits and helmets.
"The smile on his face said it all, really."
Most Whanganui drivers went to Manawatū to race and practice but there were enough locals to start a club here in town, she said.
"We have at least 20 [drivers] that go over there.
"People are members of the Palmy club and the Wellington club, and they will come up and do club days at each one.
"I think if there was a club or a track in Whanganui it would work the same way."
Helping Max behind the scenes is Blair Gray, of Kooter's Motorsport.
He was a kart racer himself in the 1990s and got back into the sport around three years ago.
"I'm his mechanic, pretty much. I help out where I can and sponsor him where I can."
Gray said he was confident that Max could crack the top 20 this weekend.
"I think his driving would put him closer to the top 10 but you just don't know what all the other guys out there are doing.
"The red mist can come over and then they do what they want.
"At the end of the day, as long as they go out and have fun, that's all we can ask for."
Gray said it would be awesome to have a track and club in Whanganui.
"To have something local would just be huge.
"The only way to get better is track time and time in the seat."
