A few bits of info confirming what was suspected, but interesting nevertheless http://en.hondaracingf1.com/newsroom/in ... e315be602f
They knew prior to winter testing that the power wasn't there
“So this year’s power unit was built up at the end of last year. In parallel, we also conducted some mono-cylinder tests and some experimental tests on other engines. However, when we fired up the complete engine for the first time, we could see it wasn't delivering the durability or performance in accordance with our expectations. We also found many minor issues. So we needed to modify tiny bits."
“After resolving these smaller elements, we started to test the full concept at the start of this year - call it Spec Zero as it was the initial one - and before the first winter test we confirmed that it ran on the dyno. But of course at that moment we knew that the power was not delivering to our target.
Oil tank rig was insufficient to identify problems
“Many items we could not test on the dyno, so it is normal that we need to check some functions in the car. The oil tank is one of the biggest items, so we have a rig for the oil tank but we cannot recreate the same types of G forces and conditions as in the car. Of course, by design we have to consider the actual car situation in theory, but sometimes it is not always the same situation so that is why we had some issues with the oil tank first.
I could read this paragraph as confirmation their 'full chassis dyno' either doesn't exist, or lacks gearbox and wheels...
“The second issue was down to the vibrations. On the dyno, the model is stiffer and heavier, so it doesn’t create any synchronised vibrations, but on the car - with the gearbox and the tyres - there is a much lower level of inertia. Low inertia does not always create vibrations but it’s completely different from the dyno and that’s why we suffered a huge vibration on the car. Of course, we were aware some level of vibration would come in the car but it was much bigger than we expected.”
A combustion concept change takes 6 months, but spec 3 (Baku) was only started in March. Interpret that as you wish to wrt. the magnitude of the Spec 3 change. I.e. Spec 3 is not actually Spec 3 (new combustion concept), as said by Wazari etc - where the true upgrade comes after the winter break.
“It depends on the items - something like the combustion system takes longer for testing and confirmation. So we cannot set a target just for two weeks later, normally such an upgrade takes something more like half a year.
But it is also important to make those kinds of developments as well, so actually the Spec 3 power unit is like that. This development started in March, more than three months ago.”