F1technical.net

Craigy wrote: ↑

04 Aug 2017, 14:04

Joseki wrote: ↑

04 Aug 2017, 11:49

Sassi has been fired by Ferrari, Honda should make an offer to him right now that he's free, he has the know how Honda needs.

Nope. He was promoted into FCA and is doing road cars now.
He still works for Marchionne.

Nope he was fired, the news is out today in Italy and Leo Turrini confirmed it.

"Personal reasons" is the official reason, that as we know is BS.

MrPotatoHead wrote: ↑

04 Aug 2017, 18:06

ziggy wrote: ↑

04 Aug 2017, 18:03

But still we dont know, how much energy is possible to harvest from the MGUH. That's one of the big secrets.

More than you think but less than you'd want

Thanks for the exact info. I allready thought it was around that number

ziggy wrote: ↑

04 Aug 2017, 21:19

MrPotatoHead wrote: ↑

04 Aug 2017, 18:06

ziggy wrote: ↑

04 Aug 2017, 18:03

But still we dont know, how much energy is possible to harvest from the MGUH. That's one of the big secrets.

More than you think but less than you'd want

Thanks for the exact info. I allready thought it was around that number

Haha I couldn't help myself.

Joseki wrote: ↑

04 Aug 2017, 18:16

Craigy wrote: ↑

04 Aug 2017, 14:04

Joseki wrote: ↑

04 Aug 2017, 11:49

Sassi has been fired by Ferrari, Honda should make an offer to him right now that he's free, he has the know how Honda needs.

Nope. He was promoted into FCA and is doing road cars now.
He still works for Marchionne.

Nope he was fired, the news is out today in Italy and Leo Turrini confirmed it.

"Personal reasons" is the official reason, that as we know is BS.

Ah, apologies. My information was out of date.

Craigy wrote: ↑

04 Aug 2017, 22:45

Joseki wrote: ↑

04 Aug 2017, 18:16

Craigy wrote: ↑

04 Aug 2017, 14:04

Nope. He was promoted into FCA and is doing road cars now.
He still works for Marchionne.

Nope he was fired, the news is out today in Italy and Leo Turrini confirmed it.

"Personal reasons" is the official reason, that as we know is BS.

Ah, apologies. My information was out of date.

No, I don' t think so.

MrPotatoHead wrote: ↑

04 Aug 2017, 18:06

ziggy wrote: ↑

04 Aug 2017, 18:03

But still we dont know, how much energy is possible to harvest from the MGUH. That's one of the big secrets.

More than you think but less than you'd want

I'd say 90kW is probably the extreme upper bound that's practically achievable. The manufacturers probably get somewhere between 40-70kW. Whether it bypasses the ES, or not is another question.

I'd say Honda's power deficit is maybe half caused by MGU-H harvesting deficiency, half from combustion power, although the two are related. Without an MGU-H the deficit would instantly be cut in half or more, however, IIRC Honda got into this engine formula precisely because they wanted to develop this MGU-H technology. However, it appears that it's not something that could be translated to road cars even with economies of scale. The combustion tech on the other hand, very much could, although may not work as well without electric supercharging, not sure.

It is all about Combustion!

Get that right then everything else falls in line.Bad combustion=low top HP and low ERS.
That is this formula......making max ERS(MGU-H) while not hurting ICE power.Must do it with lean fuel mixture because of fuel flow and fuel amount rules.Honda got it wrong in 2015 because they designed the PU like it was a high rev NA Engine.Can't blame because that is their history......they stayed away from Di/Diesels/Turbos in their production cars until lately....so they are rookies to this tech.

Need the best Software guys too and the best field test engineers(guys who find the problem fast and fix it fast,also can explain the problem in simple term so the whole team understands)

Sasha wrote: ↑

05 Aug 2017, 02:13

It is all about Combustion!

Get that right then everything else falls in line.Bad combustion=low top HP and low ERS.
That is this formula......making max ERS(MGU-H) while not hurting ICE power.Must do it with lean fuel mixture because of fuel flow and fuel amount rules.Honda got it wrong in 2015 because they designed the PU like it was a high rev NA Engine.Can't blame because that is their history......they stayed away from Di/Diesels/Turbos in their production cars until lately....so they are rookies to this tech.

Need the best Software guys too and the best field test engineers(guys who find the problem fast and fix it fast,also can explain the problem in simple term so the whole team understands)

I'm jealous now, that's precisely what I'm good at. We aren't liked very much though, we're too direct for our own good, and have no problem stepping on people's egos to point out their flaws. Comes from a lifetime of being too hard on oneself. But yes I agree, burning fuel is the main source of energy, it powers the ERS and the wheels. The ERS also feeds back into the combustion through the turbo, since the turbo has both a compressor relief valve, wastegates and an MGU-H, boost pressure, and back pressure can all be controlled precisely for the conditions. Even the MGU-K can feed into this process, at the very least it can modify the crank pumping losses or act as combustion damper(controlling crank inertia) to help control vibrations. I wouldn't be surprised if the Spa MGU-K update has something to do with that.

Sasha wrote: ↑

05 Aug 2017, 02:13

Can't blame because that is their history......they stayed away from Di/Diesels/Turbos in their production cars until lately....so they are rookies to this

The cvcc system of the first gen civic was almost identical with tji systems of these engines. With some differences in operating conditions of course

Does anybody know, in qualifying on the hot lap; do the teams use MGU-H harvesting or do they turn it down/off to run maximum ICE performance?

I reckon if you load up the ES on the out lap, you would have enough energy on your hot lap to spool up the turbo and power the MGU-K?

Because if that's the case Honda's lack of peak power in qualifying has little to do with MGU-H harvesting/effect on turbo performance.

harjan wrote: ↑

05 Aug 2017, 12:37

Does anybody know, in qualifying on the hot lap; do the teams use MGU-H harvesting or do they turn it down/off to run maximum ICE performance?

I reckon if you load up the ES on the out lap, you would have enough energy on your hot lap to spool up the turbo and power the MGU-K?

Because if that's the case Honda's lack of peak power in qualifying has little to do with MGU-H harvesting/effect on turbo performance.

Almost certainly not.

Let's take Spa, which is extreme but I've been pondering it so I have some numbers.

Last year's qualy lap spent around 70 seconds at wide open throttle. So the MGU-K will consume 120 x 70 = 8400 mJ , 8.4 mJ. The most you can provide from the ES is 4 MJ. So if they wanted to run the MGU-K of all 70 seconds they'd need 4.4 mJ from the MGU-H. That's 63 kw harvesting rate.

If they want to run some of the time with wastegates open, motoring the MGU-H from the ES, and still motor the MGU-K things get more complex.

I think they might need about 40 kw to drive the compressor. There is a ready source for the energy to do that, from braking and other harvesting techniques, such as driving against the MGU-K, harvesting from the MGU-H at part throttle etc. But, for every three seconds they drive the compressor, they lose two seconds that they can drive the MGU-K at 120kw ( always assuming they can deploy for the whole lap). Now that may well be worth it, opening the wastegates at the beginning of the straight, turning off the MGU-K at the end.

As mrpotatohead keeps saying. It's very complex. I've made up some numbers to illustrate the sort of thing that might happen. Honda may well have issues in harvesting and deploying but I don't think it is explained by the scenario you offer.

Don't forget that the MGU-H is still capable of harvesting even with the wastegates open, with "blowdown" exhaust, like in the Wright TC plane did all those years ago. I remember the Renault engine does it, or did at the beginning of the season.

Thanks a lot for your detailed explanation!

How much of the 4.4 mJ could be recovered via MGU-K under braking on that hotlap around Spa?

Is it reasonable to think the deployment is for 100 percent of the full throttle phases? I would think that on the longer straights like Kemmel and before Blanchimont when the acceleration starts to taper off you would stop deploying.

godlameroso wrote: ↑

05 Aug 2017, 16:08

Don't forget that the MGU-H is still capable of harvesting even with the wastegates open, with "blowdown" exhaust, like in the Wright TC plane did all those years ago. I remember the Renault engine does it, or did at the beginning of the season.

I'm not sure that's the case. I think it takes around 80 kw to drive the compressor and I think, although I can't remember why, that blowdown is only about 40 kw. Hence my suggestion of 40 kw drain on the ES. Maybe blowdown is more than 40 kw. Maybe a key difference between the power units is the ratio of blowdown to heat recovery. I don't know and I don't know how an external observer would find out.

Edit: I remember where the 40kw to drive the turbo comes from. It's in prof Limebeer's paper on optimal control from 2014. Can't find the paper on line but here's a presentation. http://www.matlabexpo.com/uk/2014/proce ... ystems.pdf Some grains of salt needed since he puts ICE output at 440 kw and MGU-H at 20.

Harjan

Braking at Spa in 2016 was expected to be about 13% of the lap time, according to Brembo.

That's about 14 seconds of the pole lap. If they could harvest perfectly at 120 kw that would be around 1.7 mJ . Perfection isn't possible, how far short they fall I don't know but I would think somewhere in the 1.0 to 1.2 mJ would be in the ballpark.