Michael Andretti said on Friday he was still aiming to enter Formula One in 2025 despite continued opposition from rival teams, and had a current specification car ready for testing.
The American, a former F1 racer and son of 1978 world champion Mario with successful teams in various motorsport series, told Sky Sports television his arrival would benefit the sport.
He added that there was strong fan support and it was something of a "mystery" to him why the existing 10 teams were opposed to his outfit, backed by General Motors' Cadillac brand, becoming the 11th.
The governing FIA has approved Andretti's application and sent it on to Liberty Media-owned Formula One Management (FOM) for commercial discussions, which could take some time.
"We're still shooting for '25," said Andretti. "Our car is actually going to be in the wind tunnel next week, so we have a car already built up in '23 spec, so we're flat out. We're building a team.
"At the moment it's '25, it could be '26, but we'll see."
Andretti had an agreement with Alpine for an engine but Bruno Famin, new boss of that Renault-owned team, said recently the deal had lapsed.
"Technically the agreement went out but once we get our approval then that'll be fixed," said Andretti. "We're not worried about that."
Asked if he understood the resistance from other teams, who fear the dilution of revenues, the American said it was "a mystery to me in some ways why they're pushing back".
"They say we're slicing the pie but the point is hopefully we bring in more than we're taking way," he added.
"If you look at the fan support and all the surveys that have been done, we think we're going to add to it and not take away."
Andretti said there were enough sponsors to go around and his team could help boost the sport in the United States.
"There's a lot of companies that are not in the series right now that have already contacted us, that are quite interested and that once we get approval they want to talk to us," he added.
Asked directly in a later press conference whether they had a personal grudge against Andretti, four of the team bosses denied that.
"I don't know him," said Mercedes principal and co-owner Toto Wolff.
"His father has a fantastic track record and is one of the great names of the sport. I think Andretti as a racing team has been doing well in the United States. But there's no grudge. If you haven't really met anyone you can't have a personal grudge."
Guenther Steiner, boss of U.S.-owned Haas, also said there was nothing personal while McLaren's Zak Brown said he was "good buddies with Michael" as a business partner.
Aston Martin's Mike Krack said he had worked with Andretti in Formula E and "I can only say good things about Michael and his team."