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From the Autosport Live commentary with Nico Rosberg:
I know it’s a very early stage in the game, but how different does the 2014-spec car feel from the cockpit? Are the differences in handling, sound and performance obvious?
– Nico Rosberg: “The driving is similar. The tyres are harder at the moment so that makes it a bit more difficult….and the engine is different, especially because of having the low RPM – but good torque and needing to run higher gears in the corners. Last year we did a hairpin in first gear, this year it’s maybe third.”
This goes pretty well with my suggested gearshift points above (360/257/184/131/94/67/48/34 km/h for gears 8 through 1 being at the limiter).
Another thing is the turbo pressure – as far as I can see, then due to the fuel flow limits, they will be needing much more boost at lower revs than they will be needing at higher revs. Starting from 4000 rpm, the cylinder pressure should be around 2,6 bar to feed air for the maximum allowed fuel, and it will be slowly dropping to a little below 2,4 bar at 10500 rpm. After 10500 rpm, they can’t add any more fuel flow to the engine, so the required pressure will then linearly drop to below 1,7 bar at 15000 rpm, and at the same time when they need to drop the boost pressure, they will still have the same amount of exhaust gases going through the turbo, so there will be a lot of energy to be harvested by the MGU-H unit just by slowing down the turbo, which they would need to do anyway.
Of course, every team will want to keep their engine at the 10500-15000 rpm range as much as possible (and because of the long range of maximum power, it will be easy to achieve), to provide as much power to the driver as he may need, so the lower range of revs will only be used from a standing start, but the most of the energy will come from accelerating up from 10500 rpm anyway, and that may very well mean that as long as the MGU-H unit can handle it, the teams can get most of their electrical energy from the MGU-H (since regeneration from MGU-H is not limited), and they can use a lot less than the maximum allowed regeneration of 2000 kJ per lap from the MGU-K unit, which will in turn mean less interference and better stability under braking for the drivers. That would make the MGU-K unit act more as an engine and a lot less as an energy harvester.
Yes, they certainly can’t run at maximum power at all times, but I was looking at this from the viewpoint of having maximum power potentially available to the driver at all times. At every track there will be many braking zones and corners where you cannot apply the full throttle of engine+ERS anyway, which will somewhat reduce the fuel needs, but fuel management will still be an issue.
Looking at it again, I guess the most interesting part will be the upshifting part – with the old engines and normal aspiration, the maximum power of the engine was at all times mostly limited by the revs, and when a driver upshifted, he would always initally end up with lower power at lower revs after the upshift, until he could accelerate the revs up again. That meant that (giving some room for different power curves), it would always make sense to ride each gear out to the maximum revs, to make sure you get as much power as possible before and after the upshift. But now, that the engines could potentially have a pretty much flat power curve from 10,500-15,000 rpm, there is a much wider margin for potential gearshifts, as you won’t lose out in power by shifting too early.
With that in mind, then I don’t think we will see any cars ending up in the limiter at the end of the straights, when the fuel load is lower – they will have no need to set the 8th gear so close to the rev limiter.
Also, I think that this fact is behind the fact that the teams can only designate a very limited set of gear ratios for the entire year (unlike last year, where they could and would change the ratios on every track). They simply won’t need to change the ratios, unless maybe Monaco and other street circuits need a slightly different setup at lower gears.
Another observation from today – since according to Toto Wolff, at least Mercedes were limiting their revs to 9000-10000 rpm today (https://twitter.com/ianparkesf1/status/428172858112876544), and considering that they must have been no slower than around 250-260 km/h on the straights (Hamiltons fastest lap averaged slightly over 180 km/h) then we can assume that at least at the moment, the transmission is set up so that they will hit the limiter in 8th gear only at around 400 km/h.
So either they have some really long gears set up for testing, or they don’t plan to be going anywhere near 15,000 rpm in the 8th gear (or some lower gears as well). That would seem to suggest that my assumption about the engine being at maximum power output at way lower than 15,000 rpm could be correct, and we might see this in the races as well.
Another issue that will arise, is that if we assume that the power curve will pretty much plateau after 10,500 rpm, it means that each upshift could change the gear ratio by a bit more than 1,4 times (from 15,000 rpm down to 10,500 rpm), and you would still immediately be at about the same power after the upshift. Assuming that the maximum top speed you will need all season long is about 360 km/h in 8th gear, you can cover the entire range of speeds with the car being between 10,500 and 15,000 rpm at all times (with speeds of 360/257/184/131/94/67/48/34 km/h for gears 8 through 1 being at the limiter). In this scenario, the lower gears will probably shift too often for the acceleration capabilities, but wouldn’t this be the optimal solution? There is even room for making the first gears longer, and limiting the maximum rpm for higher gears to save the engine, and you could still be above 10,500 rpm, and at maximum fuel and close to maximum power at all times.
Does this make sense? And will the engines use maximum allowed revs at all this year?
http://www.bbc.co.uk/sport/0/formula1/24016050
Looks like the deal is done and the announcement perhaps on Wednesday..
