Honda has been forced to make changes to its MGU-H and turbocharger as a result of the problem suffered by Pierre Gasly in the Australian Grand Prix.
Gasly retired early in the opening race of the season having lost power, with Honda tracing the issue back to the MGU-H. After investigations, it was found to be an incident that also affected the turbocharger and damaged Gasly's internal combustion engine (ICE), meaning modifications have had to be made and parts replaced.
Teams only have three of the ICE, turbocharger and MGU-H for use during the season before having to take grid penalties, and both Toro Rosso drivers will already move closer to those limits at this weekend's Bahrain Grand Prix.
"During the race in Australia, we had an issue with the MGU-H and turbocharger on Pierre's car and this had the knock-on effect of also damaging the ICE," Honda F1 technical director Toyoharu Tanabe said. "Therefore, in Bahrain, Pierre will use a new ICE, MGU-H and turbocharger. The MGU-H and turbocharger have both been modified, in light of what we learned in the first race.
"Given the problems we encountered in Melbourne, we have decided, as a precautionary measure, to also change the MGU-H and turbocharger on Brendon's car, fitting the new modified components.
"Replacing components for the second race is obviously a difficult decision and not ideal, given that the number of power units and ancillary components is now limited to just three per season, however we believes this is the right way forward and we will continue our development in order to ensure the same issue does not reoccur.
"Although Sakhir is a tough track for the PU, we hope to move on from this difficult moment, as we focus on this race and those that follow."
Honda only switched to supply Toro Rosso this year after three tough years with McLaren that were heavily impacted by reliability issues, leading to the early termination of that partnership.
