Honda F1 project leader Yusuke Hasegawa has outlined a number of reasons why Honda has been struggling so badly in the beginning of the 2017 Formula One season. He confirmed that lots of problems were not discovered while running on the dynamo meter.
“I have seen enough to surmise that Honda’s MGU-H is '99%' (meaning less 1% sure) 'likely' (meaning, so not sure) to be clutch-less”. You have seen no more than others have seen of the Honda’s or any of the other three MGUH/turbo set-up apart your fixation on the Garret one-piece shaft set-up which is designed for road going cars, comprising turbine, armature and compressor wheel shaft, all three machined from the solid (one piece). Of which according to your formula one set-up calculations the whole stuff rotates at no more than 85k RPM, meaning no less than 40k RPM then the maximum permitted.
. . . I have seen enough to surmise that Honda's MGUH is 99% likely to be clutchless until anyone else can convince me otherwise.
I'm with you on that PZ, in fact I will wager that NONE of the engines have a clutch or a gearbox on the MGUH. See my post three posts back.
I'm of the same thinking.
In this thread I've seen zero evidence of a high enough advantage on clutching and/or gearing the link between the turbo and the MGU-H shafts worth the weight and reliability penalties.
Engineering is always looking for compromise solutions.
It is hard enough to make bearings for such a high rotational speed to think in making a sprat clutch which needs an axial movement of one of the rotating elements to lock in the reverse torque direction, which is feasible enough in the confines of a gearbox (more space, a lot lower rotational speed, not as high temperature, not as long shaft (in the "split turbo" designs).
Same thinking applies for me to gearing the link to achieve optimal rotational speeds on the turbomachinery and the electrical machine.
Sometimes, the simplest solution is the best solution in engineering.
Now you are saying “why not simply use the same shaft? And take that same shaft the armature of the electrical (as Garret does).”. What you are saying implicates that the rotating element (armature of MGU-H) is a one-piece-shaft with the turbine and compressor wheels fixed at each end. And rotating as a direct-drive (ratio 1:1). No gearbox ratio up or down and no clutch. On the other hand according to your calculations (06 March) the bigger more efficient turbos being used, which are supposed to push more air at lower RPM, are estimated spinning at around a maximum of 85000rpm at full boost. Contrast that with what Bandid 1216 said: “One more thing, high RPM is the key to design high power to weight ratio electrical motor/generator. Otherwise the MGU-H would be big and heavy. So one wants the turbo as low RPM as possible, but the MGU-H as high RPM as possible".
There is a sweet zone between 85k and 125k where the two can meet without the extra complication of a gearbox or clutch. A small compromise in MGUH or compressor rpm is very easy and would present a far smaller weight penalty than a gearbox or clutch. . . and then there is the reliability risk.
I could not agree more. Also, if they can choose between a 25kW mgu-h of 4 kg and a 50 kW mgu-h of 8 kg, I would put my money on the bigger one.
Ghost, you have failed to bring supporting evidence or solid engineering theory to back-up your claims even after a barrage of evidence countering your arguments. You have floundered in posts dragging out the conversations to no avail. Therfore I have seen enough to surmise that Honda's MGUH is 99% likely to be clutchless until anyone else can convince me otherwise.
I wish you could see your reflection, Ghost.
So you're saying unless I bring you a photo or indeed an in the metal MGU-H from a current F1 power unit, your Garrett electric road car turbo must be correct? That's a little self important of you.
The fact of the matter is you're guessing just as much as I am. The difference being you think they won't bother, I assume they will look for gains anywhere at this point
The one who has floundered is you that consistently sidesteps every question I've asked. You're whole argument is literally "this road car Garrett turbo I found online doesn't have a clutch, so clearly, F1 doesnt".... Seriously??
I've not once claimed I have conclusive evidence, I rather harmlessly suggested in theory there could be a benefit if they get it right. But now, I almost feel like you've got a bet going to put Garrett in every single reply, and on that ... please for the love of God, don't send me to the Garrett website again.
. . . I have seen enough to surmise that Honda's MGUH is 99% likely to be clutchless until anyone else can convince me otherwise.
I'm with you on that PZ, in fact I will wager that NONE of the engines have a clutch or a gearbox on the MGUH. See my post three posts back.
I'm of the same thinking.
In this thread I've seen zero evidence of a high enough advantage on clutching and/or gearing the link between the turbo and the MGU-H shafts worth the weight and reliability penalties.
Engineering is always looking for compromise solutions.
It is hard enough to make bearings for such a high rotational speed to think in making a sprat clutch which needs an axial movement of one of the rotating elements to lock in the reverse torque direction, which is feasible enough in the confines of a gearbox (more space, a lot lower rotational speed, not as high temperature, not as long shaft (in the "split turbo" designs).
Same thinking applies for me to gearing the link to achieve optimal rotational speeds on the turbomachinery and the electrical machine.
Sometimes, the simplest solution is the best solution in engineering.
Well no, and until we get to carve one of these engines open, you won't get conclusive evidence. This weight penalty and reliability excuse is curious. I can't see the weight penalty being as horrendous as what's being implied and they've had horrid MGU-H reliability in the past and only now getting it right.
All I'm saying is it's not outside the realms of possibility and the only oppositional explanations that have been put forward are either "this Garrett turbo doesn't have a clutch, so there" or "nah too heavy/unreliable". Both assumptions and both just as opinionated as the clutched idea.
Sadly I don't have a 2020 Honda F1 Power Unit in my study to dissect for everyone's benefit so lets just move on. There will always be two sides of the fence.
Well no, and until we get to carve one of these engines open, you won't get conclusive evidence. This weight penalty and reliability excuse is curious. I can't see the weight penalty being as horrendous as what's being implied and they've had horrid MGU-H reliability in the past and only now getting it right.
All I'm saying is it's not outside the realms of possibility and the only oppositional explanations that have been put forward are either "this Garrett turbo doesn't have a clutch, so there" or "nah too heavy/unreliable". Both assumptions and both just as opinionated as the clutched idea.
Sadly I don't have a 2020 Honda F1 Power Unit in my study to dissect for everyone's benefit so lets just move on. There will always be two sides of the fence.
The weight and reliability penalties are there, like it or not, they are facts. If you don't concede this, then we can stop discussing here about this kind of engineering challenges.
What I'm honestly falling to understand is the benefit of the clutch/gearing in laptime and/or efficiency of the PU. Can you develop it more? Can you show some estimations of the gains to suggest it's worth the penalties implied in such a design proposal?
I don't see any benefit of clutching at all, to be honest. Where would you want to spin up one and not the other? If you're trying to spool the turbo fast you'd use the H to assist it, if you're on full deployment qualifying mode and for some reason have power/fuel to spare at full throttle down a straight you'd be better off harvesting it and using it for drive out of the next corner than decoupling the MGU-H (and if you didn't need it you'd just drive the excess through the H anyway)
If during a race the rotating elements such as bearings of the MGU-H or MGU-K for that matter are damaged and there is no clutch to disconnect the car will have to be stopped.
Ghost, you have failed to bring supporting evidence or solid engineering theory to back-up your claims even after a barrage of evidence countering your arguments. You have floundered in posts dragging out the conversations to no avail. Therfore I have seen enough to surmise that Honda's MGUH is 99% likely to be clutchless until anyone else can convince me otherwise.
I wish you could see your reflection, Ghost.
So you're saying unless I bring you a photo or indeed an in the metal MGU-H from a current F1 power unit, your Garrett electric road car turbo must be correct? That's a little self important of you.
The fact of the matter is you're guessing just as much as I am. The difference being you think they won't bother, I assume they will look for gains anywhere at this point
The one who has floundered is you that consistently sidesteps every question I've asked. You're whole argument is literally "this road car Garrett turbo I found online doesn't have a clutch, so clearly, F1 doesnt".... Seriously??
I've not once claimed I have conclusive evidence, I rather harmlessly suggested in theory there could be a benefit if they get it right. But now, I almost feel like you've got a bet going to put Garrett in every single reply, and on that ... please for the love of God, don't send me to the Garrett website again.
I answered your questions in the science articles linked. I cant win with you unless a photo of an F1 MGUH is sliced inbhalf emerges on the internet. Or maybe Yamamoto himself answers if there is a clutch.
Anyway. I am satifsified in myself that there is no clutch.
garrett would have leverage experience and investments in F1 to use a similar system for the production car applications. I doubt the technology would be far off.
If during a race the rotating elements such as bearings of the MGU-H or MGU-K for that matter are damaged and there is no clutch to disconnect the car will have to be stopped.
The car will be stopped anyway, no way in hell you're going to risk the debris in the rest of the power unit.
If during a race the rotating elements such as bearings of the MGU-H or MGU-K for that matter are damaged and there is no clutch to disconnect the car will have to be stopped.
That wouldn't affect the MGUH/K as much as you think. If the MGUH/K is in motor mode and the bearings get damaged the energy wouldn't have anywhere to go and the units would overheat and burn up... Fortunately, the elctronics are designed to detect this and cut power automatically.
This is standard on common industrial motor drives. You can set limiting currents and other things. These drive can even read the feedback from the phases and detect if the shaft is unbalanced, hot connections, power factors etc. Some complicated math. The motor itself would also come with temperature sensors.
If during a race the rotating elements such as bearings of the MGU-H or MGU-K for that matter are damaged and there is no clutch to disconnect the car will have to be stopped.
The car will be stopped anyway, no way in hell you're going to risk the debris in the rest of the power unit.
How will debris from inside the MGU-H or MGU-K can get into the rest of the power unit?