Ron Dennis is confident that the "pain" McLaren and Honda are going through at the moment is part of "learning curve" that will help them to be competitive.
On the back of a disastrous campaign, things came to a head at Honda's home race, the Japanese Grand Prix, over the weekend as Fernando Alonso’s frustrations reached boiling point.
The two-time World Champion told the team that it "is embarrassing" being overtaken by Toro Rosso's Carlos Sainz and Marcus Ericsson in the Sauber, latter adding that his power unit was like a "GP2 engine" and called .
Dennis admitted that he can't "condone those sort of things", but he remains optimistic that both McLaren and Honda will get through this difficult period together.
"I still can't understand why everyone doesn't appreciate you're not going to win a World Championship if you have a second-string engine [as a customer team]. It's just not going to happen.
"Therefore we have to go through the pain, we have to go through this learning curve and get a competitive engine.
"That's not a derogatory comment against Honda. The president of the company, the president of R&D, the president of Honda Motor Company are totally committed.
"They understand what needs to be done, they're increasing resources, putting more money and effort into it, and we will get there.
"It's just a bit painful at the moment."
The 2015 season was always going to be one of consolidation for Honda, but on the back of their poor start, they tried to speed things up and that has backfired.
"Timeframe in an engine term is very controlled by what is a shifting position on tokens, black box versus white box, the freezing of specific components," Dennis said.
"Only when you have significant improvement do you introduce an engine change with tokens, and theoretically, in an ideal world, that should be for every fourth race.
"We've tried to move forward faster and that has affected reliability, it's made the whole thing more challenging.
"In the end, this very acute pain we have inflicted to a certain degree on ourselves is the fastest way to get back to where we need to be."