At the same time, Haas was trying to put together a 200-strong workforce.
"There are many interested parties," a source told Auto Motor und Sport last week, "but we can only hire people when we know who our engine partner is."
At the Indianapolis 500 last weekend, Haas told motorsport.com that plans to use Ferrari technology are on track. "We haven't exactly signed a formal contract (with Ferrari) but we're pretty close," he said.
And he met with likely chassis maker Dallara during the Indianapolis visit.
"They all can do it, they all want to do it, they're all very interested in helping us," said Haas.
He hinted, however, that time is running out to be ready for 2015.
"I think they are looking at it as a good long-time partnership but it just comes down to you have to order things and it takes time to order things and get things scheduled.
"It just seems that it's taking longer to accomplish what we wanted to do than we thought," Haas added.
The latest news is that Haas has apparently now decided to target a 2016 debut rather than rush onto next year's grid.
"It's already June," he said, "so it's just seven months away and the timing issues are starting to get real crazy."