roon wrote: ↑
Sun Jul 07, 2019 6:36 am
Regarding overheating in Austria: was this a reference to engine water temperature, electrical device water temperature, oil temperature, or charge air temperature? Or some combination of the aformentioned, potentially?
Might also be related to CC temperatures. Lower RPM peak power may be, for example, more efficient but harder upon componentry. Shifting the powerband up could relieve the crankshaft, pistons, conrods, and journals via reduced peak cylinder pressures and temperatures. Shifting it down may increase combustion efficiency and power but may be more reliant upon water and oil cooling of the combustion chamber.
If oil temperatures could not be reduced via the heat exchangers sufficiently, then sufficient control of piston crown temperature might also be lost, forcing the use of engine modes that shift the powerband higher. I'm reminded of the advantages of steel piston crowns in this context.
If not crown temperature related, maybe they were at the edge of their oil's operating temperature i.e. higher power engine modes rely upon oil properties which might be lost above a threshold temperature.
If not ICE related, could be that they were preserving the ES or the electric motors. They were lifting at the end of straights, which might suggest the issue was not on the electrical side of the powertrain.
If it is charge air cooling related, this may be the long tail of engine oil regulations changes. Recall that this is only the second season where oil composition and consumption are explicitly defined. It was essentially confirmed by the 2018 regulations that at least someone was using octane boosting compounds that could be boiled out of engine oil above 210°C. If charge temperatures rise, an octane boosting oil might have been what prevented detonation in previous seasons. Now they may be left with altering other parameters which in turn reduce power output.
it's a fun thing to speculate. Martin Brundle mentioned 30 radiators in some cars, presumably each of them has a calculation, of joules dissipated with its airflow of velocity X and air density, humidity and temperature and they were pretty much all out of specification in Austria, all the same, otherwise some were over-specified weren't they. Tho there's a question of how much cooling is done in a shared way with the same coolant so if they can reduce one item in the chain it helps the others
and now there must be teams of engineers slaving away trying to dissipate more joules without messing up the aero, with coatings, textures, the fluid (is there anything better than water?) the ducting and every single little thing. Oil isn't a great coolant is it perhaps they're on at Petronas too. Wish they'd tell us more about it, i bet the other teams have plenty of ex-Mercedes staff telling them!
Anyway if they're 'only' 3rd and 5th in Austria and Mexico that's still a great car over the season. Hungary I suppose.