With his pregnant partner and two other young children in the car, Te Ariki Wiringi drove at 120km/h past two Rotorua schools.
He was enraged after having an argument with his partner about her past relationships and later told police he wanted to "scare" her.
His partner begged the 22-year-old to slow down, fearing for the children at Selwyn Primary School and Western Heights High School as he sped dangerously on Old Quarry Rd, an area with a speed limit of 50km/h.
But he didn't stop, saying he didn't care if he crashed and killed them all, details in police documents reveal.
Wiringi is now behind bars as his former partner is about to give birth to their new child after he pleaded guilty in the Rotorua District Court to three charges.
They included threatening to kill by deliberately crashing a vehicle, dangerous driving and contravening a protection order.
A police summary of facts released to the Rotorua Daily Post said Wiringi and the woman had one child together, aged 3, and a step child, aged 1.
Both children were in the car on February 27 when Wiringi drove a Subaru vehicle and lost his temper.
After becoming enraged, Wiringi drove past the two schools at 120km/h, refusing to stop, the summary said. It was 11am and children at both schools were in session at the time.
As Wiringi neared the end of Old Quarry Rd, he slowed but continued to drive along Gordon Rd. He then turned into Fairview Rd and accelerated to 80km/h.
The woman was begging him to stop but instead he drove up onto the footpath and hit a bus stop sign, causing it to hit the window screen of the vehicle and making it difficult to see.
The woman tried to call police but he grabbed her phone and threw it out the vehicle, the summary of facts said.
Still driving at speed, he failed to stop at a road works stop sign. At this time, the woman hung out the window of the car and yelled at the road workers to call police.
Wiringi then drove to a property on Cherrywood Pl and told the woman to leave in the vehicle.
When interviewed by police, he admitted driving the car and said he wanted to "scare" the woman.
Wiringi has two previous family harm-related convictions involving the same woman, the summary said.
He has been remanded in custody and will be sentenced on July 30.