Honda Power Unit Hardware & Software

[Sixbarboost]

What are you saying, that input and output is not the same?

[FW17]

Sad to here there won't be a Suzuka special

[trinidefender]

What are you saying, that input and output is not the same?

You aren't understanding the regulations properly. There is a 120 kW power limit on the MGU-K. However there is also a 4 MJ energy limit output on the MGU-K that can come from the ES. There is also a 2 MJ energy limit that the MGU-K can send to the ES per lap.

This means that at max capacity the ES can only supply the MGU-K with 120 kW for 33.3 seconds a lap. To increase the time that you can supply power to the MGU-K then you will have to do one of two things. Reduce the power output of the MGU-K or get the power from somewhere else. These PU's get that extra electrical energy from the MGU-H as there is no energy limit from MGU-H to MGU-K.

That is where the tricky part comes in. It becomes a balancing act for the PU manufacturers to maximise ICE output and maximise MGU-H output going to charge the ES (remember that the ES can only receive 2 MJ of energy per lap from the MGU-K from regenerative braking) and powering the MGU-K.

[godlameroso]

So in essence then the MGU-H is limited to 2MJ to the ES, and since the MGU-K is limited to 120kW, then basically the only thing the MGU-H can do is allow you to deploy the MGU-K for longer than 33.3 seconds.

[wuzak]

So in essence then the MGU-H is limited to 2MJ to the ES, and since the MGU-K is limited to 120kW, then basically the only thing the MGU-H can do is allow you to deploy the MGU-K for longer than 33.3 seconds.

The energy the MGUH can transfer into and out of the ES is unlimited.

The MGUH->MGUK transfer allows the PU to have more power more of the time, and I would expect that most of the time the MGUH dumps directly to the MGUK.

[nanocustic]

Well hello there. I've been following this forum for quite some time. Every time a season starts I come here to check what's coming in terms of silly season, and all F1 related)

So now, on the Autosport page I read this:

Honda aiming to match Ferrari with Formula 1 power unit update

With some interesting points from Arai, which I think I'll take with a pinch of salt:

- Existing engine was "much better than Renault" and that the upgraded version (mk3) will take it closer to Ferrari's output.
- Mk 4 will be closer to Mercedes output.
- Arai mentions that the chassis definitely masks the engine performance, due to lack of miles covered in testing.

[godlameroso]

Sorry but isn't total ES capacity 4MJ, of which 2MJ max comes from MGU-K recovery? So the MGU-H has to supply the other 2MJ, and also isn't max power to the MGU-K limited to 120KW? So practically speaking from ES to MGU-K only 4MJ of energy can go to the MGU-K @120kW per lap. How would the MGU-H give more power than 120kW to the MGU-K?

I gather then that there is unlimited MGU-H to ES, but not unlimited MGU-H to MGU-K(limited to 120kW), unless the ES is fully charged, then you could deploy 4MJ from ES + whatever you can get from the MGU-H, only any excess would basically allow longer deployment than 33.3 seconds because any way you slice it, you either send power directly to MGU-K and save some ES, or send ES to MGU-K while simultaneously replenishing with MGU-H. At least that's how I interpret it, I could be and most likely am wrong.

*edit a word

[trinidefender]

Sorry but isn't total ES capacity 4MJ, of which 2MJ max comes from MGU-K recovery? So the MGU-H has to supply the other 2MJ, and also isn't max power to the MGU-K limited to 120KW? So practically speaking from ES to MGU-K only 4MJ of energy can go to the MGU-K @120kW per lap. How would the MGU-H give more power than 120kW to the MGU-K?

I gather then that there is unlimited MGU-H to ES, but not unlimited MGU-H to MGU-K(limited to 120kW), unless the ES is fully charged, then you could deploy 4MJ from ES + whatever you can get from the MGU-H, only any excess would basically allow longer deployment than 33.3 seconds because any way you slice it, you either send power directly to MGU-K and save some ES, or send ES to MGU-K while simultaneously replenishing with MGU-H. At least that's how I interpret it, I could be and most likely am wrong.

*edit a word

You are confusing kW (a measurement of power with) MJ (mega joules, a measurement of energy) do a quick google search and it should make more sense.

P.s. Do not confuse kWh with kW either.

[godlameroso]

I think I get it, kW is a measure of power, that means work over time. MJ is a measure of energy, or the ability to do work. Technically if you didn't have a kW limit on the MGU-K you could theoretically deploy 4MJ in a fraction second and make easily over a gW of power but for a very short time. However under the regulations the output from the MGU-K is limited to 120kW, there's 4MJ available from the ES, and unlimited from the MGU-H, no matter how much energy you have, the output at the MGU-K will never exceed 120kW of power, or am I missing something? Basically I'm asking if it's possible to exceed 120kW output of the MGU-K with MGU-H + ES.

[wuzak]

No, the MGUK limit is only 120kW, so you cannot get more power out of it.

But you most certainly can put more than 4MJ through the MGUK - some from the ES and some from the MGUH.

[Tommy Cookers]

the 120 kW is electrical power into motor/out of generator and allows assumption of 95% efficiency
so mu-k power at the mechanical delivery point and gu-k power at the electrical delivery point would be eg a legal 121-122 kW
the mgu-k is torque-capped (to 200 Nm ?) so mgu-k power will fall below this 120 kW limit at lowish rpm

iirc some circuits will not yield 2 MJ from KE recovery (that would need 16.7 sec of hard braking at highish DF)
but there's nothing preventing ICE power going directly into gu-k action provided the net output (ie to wheels) is zero
so fuel can be used to produce electrical energy for storage, and allow the 2 MJ limit to be reached
ie action in gu-k mode is not limited to recovery of waste energy
(and never was, even when called KERS)

[gruntguru]

2 MJ from KE recovery (that would need 16.7 sec of hard braking at highish DF)

A quick calc gives 120 kW @ 60 km/hr @ 7 kN retardation (mu = 2.0 and 350 kg on rear wheels which would be close to the traction limit at 60 or 70 kph)

[Tommy Cookers]

it may be that the rear braking can be 100% regenerative brake load and 0% friction brake load ?

but where will there be 2g braking down to such a slow speed ?
typically at the slower speeds the driver is braking and turning ie the braking element is much less than 2g
and at this time the driver would find regen intrusive anyway ?

[Sixbarboost]

According to Brembo, the braking before the Montreal hairpin goes from 308 Km/h to 126 in 1.22 sec, using a power of 2076 kW, which in theory should generate 2.5 MJ if all of it could be harvested. From one corner alone.

They are only scratching the surface.

[Abarth]

According to Brembo, the braking before the Montreal hairpin goes from 308 Km/h to 126 in 1.22 sec, using a power of 2076 kW, which in theory should generate 2.5 MJ if all of it could be harvested. From one corner alone.

They are only scratching the surface.

Well....
-they are not braking only with the rear axle...
-They can only harvest with 120kW...if they would be able to break with 1000kW at the rear, 880kW have to be with convetional friction.

-Having electrical motors which could do this job would be big and heavy, not so speak about energy storage and power electronics, which must rectify and store such huge power. Not possible within reasonable packaging and weight.

LMP cars are allowed to harvest with front axle too AFAIK.