The Honda-powered team sits ninth in the championship, and has suffered nine retirements (three of them with both cars in one Grand Prix) in 10 races along with several stoppages during the practice and qualifying sessions.

Arai says that the power-unit package is so complicated that one failure in a small component triggers a domino effect.

“If you try to harvest energy using the MGU-H, it puts a strenuous workload on the turbo,” he said. “When the turbo is under stress, it cannot do what it is supposed to do, which is to force more air into the engine, thus leading to decreased power output.

“This is the result of one component working against the others, instead of working together.

“These types of technical chain reactions, which lead to vehicle stoppage, were definitely more than we calculated, or more than we envisioned.”

Focus now to increase power

Arai said Honda is confident that its reliability issues have been fixed, and that it is now focusing attention on increasing the power of the engine.

“After the summer shutdown our plan is to apply a new-spec engine using some of our remaining seven tokens,” he said.

“The most important area for us to concentrate on is the combustion. Current regulations require high efficiency of the combustion so we want to change the characteristic with the chamber design and intake and exhaust system layout.

“Another issue we will be addressing is reducing mechanical friction by changing the gear train system along with the combustion.”

He added that Honda will not have all its upgrades ready for the Belgian Grand Prix – one of the most engine-critical events on the calendar – but some will be ready for Spa, and the rest will be implemented during the following races.

Big improvements planned

Arai admitted that Honda will likely serve more penalties in the second half of the season, but says that it will also make “big improvements”.

When asked about progress in terms of next season, he said that the focus has shifted to it but they are also concentrating in improving in the second half of 2015.

“We value 2015 as much as 2016 because the regulations will remain the same,” he said. “This means we can develop an idea for 2016, and if it works we can implement it in 2015.”

Dismissing reports about his role being under threat, he added: “I think that I have what it takes to drive this project. I hope to continue driving this project and I believe that our board members trust me emphatically.”