MotoGP's Technical Director has rejected KTM's claim that Honda exceeded the official Moto3 rev limit during the 2015 season. In an official statement issued today, Danny Aldridge said that he and his technical team had examined the official rev limiter used in Moto3 and verified that it was operating correctly, and that although there had been overshoots of the rev limit, these were very small and very brief.
Aldridge went on to confirm much of what MotoMatters.com had found when we investigated the issue at the end of February. Speaking to Peter Bom, crew chief of 2015 Moto3 world champion on a Honda Danny Kent, Bom explained that the issue had been about the way in which Honda had optimized the point at which the rev limiter cut in, and this is what had caused the confusion. The Honda approach was very different to that of KTM, meaning that riders who had switched from Honda to KTM in 2016 were reporting to KTM engineers that the Honda felt like it had been over-revving.
In the statement put out by Aldridge, the Technical Director explained that a high revving single cylinder 250cc four stroke engine was hard to stop in its tracks once it reached the rev limit. The time it took between the moment the ECU identified that the rev limit had been breached and the point at which it started to cut the ignition was long enough for their to be a very brief overrun of the allowed rev limit. These were, however, only "modest and temporary".
The issue is to be discussed further at Qatar, in the Moto3 Class Working Group, which includes representatives of all of the manufacturers racing in Moto3. No doubt the finer details will be thrashed out there, when Honda and KTM will meet face to face to discuss their differences.
The official statement is shown below.
Statement Of the Technical Director:
Moto3 Class Maximum Rev Limits
You will probably be aware that there was recent speculation in the specialist media that data existed which showed some Moto3 machines exceeding the maximum 13,500 rpm limit imposed in the regulations.
Frankly, this came as no surprise to us because with a single cylinder 4-stroke engine it is very difficult for the ECU to cut power at precisely the moment when the rev limit is reached. Depending on the signal used by the ECU to measure the revs there can be a period of a few milliseconds where target revs are exceeded by a small amount.
After further checks on the 2015 limiter we have established that there is nothing unusual or unexpected about how the rev limiter works and that the cut point is consistent on all engines. Nevertheless, moderate and temporary overshoots of the defined rev limit were identified.
All regulations for the Moto3 class are agreed within the Moto3 Class Working Group which includes delegates from all participating manufacturers. A meeting of this Group had already been convened to take place during the Qatar GP. The original purpose was to discuss future developments in this class. We will now add the rev limit issue to the agenda for this meeting.
There is no desire to reduce the point at which the limiter cuts power just to avoid data showing minimal overshoots. It may therefore be necessary to modify regulations to take account of inevitable overshoots but, of course, other solutions may also be considered by the working group.
Further information will be provided after the Qatar meeting.
MotoGP Technical Director