Mudflap wrote: ↑15 Oct 2018, 17:05
PZ we've been talking about torsional vibration specifically. Yes, there are many other characteristics that can't be replicated on the dyno, I agree (even though oil tank behaviour can be simulated on so called rodeo rigs and turbos are usually ran on gas stands which are adequate for assessing the rotordynamic behaviour).
I don't know what conclusions to draw from this issue other than it is something that should have been spotted before the car ran at the track. It is definitely an integration issue so the responsibility lies with both Honda and TR.
All in all it is probably a fairly minor problem than has been resolved without any hardware changes and minor performance implications.
One thing to remember though Mudflap, your experience may be with conventional combustion and direct injection engines, but it may be possible that these TJI or whatever prechamber you want to call it, engines may have extreme sensitivity to external influences given the delicacy of the combustion.
It may very well be true that inertial forces from the gear box, coupled with traction oscillations, and cornering gs could have some effect on what's happening in the little piston bowl on these engines and these same forces on a contemporary DI engine may not have the same impact on the combustion process.
Of course i don't know the specifics, but i believe it may be some phenomena outside of your experience, given the F1 cars are the only ones with this type of combustion extreme.Give it some thought.
I'm going to get even more imaginative and go as far as to suspect that the combustion is so precise and on the limit that certain vibration can lead to loss of control of the combustion itself and result in detonation.