F1technical.net

NL_Fer wrote:Who knows, the Japanees only looked at a proper sized turbo for the engine and looked at the mgu-h' harvest function as a replacement of the wastegate, instead of a major source of ERS power.

They are not that stupid. These are multi-million dollar projects and even the guy who cleans the toilets knows the engine is a turbo-compound.

I think some of you hit the nail right on the head. One is the MGU K speed limit. Two is the size of the turbine or rather volume related efficiency of the turbine/compressor combination. Turbo RPM is not an issue. I also believe that Honda's ICE is now on par with Ferrari and possibly Merc at this point.

Wazari wrote:I think some of you hit the nail right on the head. One is the MGU K speed limit. Two is the size of the turbine or rather volume related efficiency of the turbine/compressor combination. Turbo RPM is not an issue. I also believe that Honda's ICE is now on par with Ferrari and possibly Merc at this point.

MGU-K speed limit? I haven't heard anything about that before, care to elaborate? As the MGU-K is tied to crankshaft rpm is there a problem revving with reliability (maybe the MGU-K) seals when the car spends to long at high rpm? Is that why we haven't seen the honda revving to the high 12000 range that we see other ICE units revving to?

Regulations state that the max speed the MGU-H can attain is 125000 rpm. Wazari probably made a typo there.

No it wasn't a typo. The MGU-K unit's rev limit of 50,000 RPM is nowhere near being maximized in the Honda PU.

Technical specification

ENGINE : ENERGY-F1 2015

Displacement 1.6L V6
Number of cylinders 6
Rev limit 15,000rpm
Pressure charging Single turbocharger, unlimited boost pressure (typical maximum 3.5 bar abs due to fuel flow limit)
Fuel flow limit 100 kg/h
Permitted fuel quantity per race 100 kg
Configuration 90° V6
Bore 80mm
Stroke 53mm
Crank height 90mm
Nomber of valves 4 per cylinder, 24
Exhausts Single exhaust outlet, from turbine on car center line
Fuel Direct fuel injection

ENERGY RECOVERY SYSTEMS

MGU-K rpm Max 50,000rpm
MGU-K power Max 120kW
Energy recovered by MGU-K Max 2MJ/lap
Energy released by MGU-K Max 4MJ/lap
MGU-H rpm >100,000rpm Max 125,000rpm
Energy recovered by MGU-H Unlimited (> 2MJ/lap)

GENERAL

Weight Min 145kg
Number of Power Units permitted per driver per year 4
Total horsepower Approx 850hp)

Wazari is right. This is from mercedes amg official web

How would the extra MGU-K speed benefit Honda?

OK.. With a faster motor these things you may benefit from:

Smaller magnets (whether electro or earth mangets)
Can have a smaller armature too.
So generally your motor is smaller and easier to control (lower inertia)

Also I think it has a wider application range over the rpm of the engine. Meaning you have a wider operating range so you can more finely adjust the motor speed.
You can employ a larger diameter intermediate gear too... so that helps somewhat with durability.

Just my guesses though.

F1NAC wrote:Wazari is right. This is from mercedes amg official web

http://i65.tinypic.com/25qu62b.png

Those are just the current F1 rules section 5.x.x and appendices in a handy table .... nothing Mercedes specific ,no actual data.
The 50k rpm figure is rule 5.2.3 max rpm.

Rob

The mguK is attached to the crankshaft and so spins at the same speed as the engine. I don't think gearing up the speed would be much of an advantage, perhaps the mguK would be slightly smaller but under more strain?

It has better speed control i feel, and less inertial shock to the gearbox once turned on.

hemichromis wrote:The mguK is attached to the crankshaft and so spins at the same speed as the engine. ....

no it doesn't
its geared (as was the KERS MG unit)
that 50000 rpm limit is there because they wanted it that way

a sub 50000 rpm electrical machine might well be a better machine or a better shaped machine than the 100000 rpm MG-UHs

I had no idea that it was geared. I assumed losses would be high enough to make a direct link advantageous.

From 50k to 12k rpm the looses should be quite high, more than in a conventional ICE actually, 24% efficiency when most electric motors run above 90%

@ hemichromis
a direct drive (or 1:1 geared really) MGU-K would need to work at 200 Nm shaft torque, motoring and generating
geared say 3:1 it would only need to work at 67 Nm shaft torque (so giving 200 Nm at the ICE crankshaft)
a much smaller and lighter machine
(presumably the rulemakers anyway wanted the MGU-K to be gear-coupled to the ICE, not an integral part of it)