A group of Kiwis are returning to Bonneville Speed Week with the world's fastest Mini to take care of "unfinished business". The Project '64 team who are behind the specially modified Morris Mini Cooper S, are taking it back to the Bonneville Salt Flats, Utah to have another crack at setting a new world land speed record. The Mini broke the record for the 1000cc class at Bonneville Speed Week in 2012, officially clocking 146 miles per hour (234kmh). However, the vehicle unofficially hit 156mph (251kmh) and team member Garry Orton said that is what's driving the team back to the Bonneville this year. "We only set the Bonneville record at 146mph, our 156mph didn't count because we didn't do it twice, we ran out of time because we had so many problems. So there was some unfinished business I guess you'd say," Orton said. About six months after they returned from America in 2012, Orton said the team decided they wanted to have a go at raising the current record even higher. They planned on going in 2014, but the crankshafts being manufactured in America weren't ready so they put it off. After hearing they would be ready in February, the team committed to attending the 2015 Speed Week. They have been working around the clock on the Mini to get it ready to race again during the last month. "The crankshaft is the first thing that goes into the engine when you are building it and we only got them four weeks ago," said Orton. "We built two engines, our last engines were sort of buggered after it. We have changed a lot of things." Team member Guy Griffith will continue to work on the car before it is flown to Los Angeles next week ahead of the event. Orton said their attempt to set a new record wouldn't be possible without support from sponsors. "When you are doing it with no money you are relying on so many other people to help," said Orton. The team are hoping to reach 170 miles per hour (273 kmh) this time around. Ad Feedback "We are wanting to raise it by another 20 kilometres per hour if we are lucky," said Orton. The new engine had a lot more power but the salt was slippery. "We were getting wheelspins over 100 miles per hour as it was so now we will only get more." He said on paper, it looked like they had a promising chance of setting a new record. "But the faster you go, the harder it gets, it's a big tall ask." To follow the speedy Mini's progress visit its Facebook page Project '64.