godlameroso wrote:Apparently they've been working on the 2017 power unit for the better part of last year, and ramping up development as the season went on. I don't think we'll ever really know how many engines they run on the dyno and for how long, nor will we ever learn how the power unit evolves. I remember Mercedes saying that they started with a very large and overweight power unit, and that the engineering process was much like a sculptor, in that all the inessentials were trimmed away to reveal the final product. In other words they started large, much like the design of computer chips, and then worried about downsizing components making them stronger lighter, and more compact.
The process used to develop these engines is probably more secret than the resulting engines themselves, so I also doubt we'll ever find out about that. As an aside, a while ago I was at an IMechE lecture involving the Mercedes F1 team, and a question popped up from an aerodynamicist in the crowd about the sample frequency of Mercedes wind tunnel laser-scanned smoke during their aero development work. The Mercedes PR people jumped in to stop the complete answer from being given (I'm sure the aero guy would have wanted to give it and also been too professional to give it..). The process itself is part of their closely-guarded secret sauce, especially given the limited tunnel and CFD time available through the regulations. The PU process is just as closely kept.
For these complex PUs, I think that it's quite likely that lots of the component work is done in isolation, otherwise there are too many variables to capture data from, even when establishing the basics that each part is doing what it needs to (turbo generating correct pressures at expected RPM, that sort of thing). It would mean you could develop each part to the breaking point, make it run hotter/higher pressure, or indeed redevelop it to be lighter or smaller, and iterate as Godlamerso suggests. Rolls Royce's technique was (and remains) to do this: run the thing until it breaks, then redevelop it to be better. Iterative development.
Obviously, some things will be a fundamental shift in concept (HCCI/TJI, whatever) and will require probably all of the components to change at the same time: two separate branches of development. Even so, the overall process is likely to involve separation to stop the thing becoming a gordian knot of complexity. The components need to be tightly cohesive but loosely coupled (borrowing a term from software development there).
I think the fundamentals of the turbo, or intercooler(s), or (and especially) the combustion concept can be done more quickly and in isolated teams of developers with external simulation of the environment they need to work in - eg boost pressure, gases/fluids at the relevant temperatures/pressures, and so on.
Obviously they'll all be brought together to form the complete PU eventually, and integration tested on a bench somewhere, then integration tested in a chassis on a rig, then track tested, and ideally all of that will happen on time, instead of the first integration testing happening at a track during the preseason as we've unfortunately seen before due presumably to delays elsewhere.
I'm one of those sad people these days: a fan of McLaren. I want to see a McLaren test day (100km filming day) somewhere before the first test. It has worked in the past for Mercedes to get these minor things sorted out, so that in the initial testing the cars hit the track absolutely niggle-free, and run huge mileages so that they can do advanced things about understanding the real life of each of the components in track testing. It's the only time of the year this is possible.