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Re: Honda Power Unit
Posted: 05 May 2017, 11:18
by Craigy
Tommy Cookers wrote: ↑05 May 2017, 10:56
it's interesting to me that Wazari asks here the question that I asked 5 years ago - why not design around systematically higher rpm ?
eg I suggested that 13000-14800 rpm had some advantages over 10500-12100
mainly 'boost' pressure would be lower ie the supercharging power reduced in greater proportion (eg 23000 would be NA)
the recoverable energy is at least the same at this lower boost
and much less ES energy is used in 'spooling up'
ok at that time I was assuming a mildly lean AFR not very lean
clearly if the very lean TJI or similar suffers at these higher rpm then higher rpm is not on
Parasitic losses from friction are always going to be higher the faster the ICE spins, although I suppose those losses might be smaller in F1 than I expect because of the types of finish used, which reduce friction to a degree unseen in "normal" engines. If the new little Honda ICE has very little internal friction in use, then perhaps that friction concern becomes a lower order than something else.
I'm trying to work out a reason why you would want more PU cycles for the same distance travelled.
Is it easier to run the engine on the absolute limit of knock if you have a larger number of smaller ignition events? Probably.
Re: Honda Power Unit
Posted: 05 May 2017, 11:27
by bigblue
Craigy wrote: ↑05 May 2017, 10:59
bigblue wrote: ↑05 May 2017, 10:32
Silverstone / Spa seems a long way off...
70 days. In the scheme of bringing a PU together, that's a blink of an eye.
I know, just there's always a need for some major revamp ... just feeling frustrated. I know nothing about designing engines but appreciate the complexities must be horrendous. Wonder if a revised block, or whatever's required to fix vibrations, can arrive before the new heads and then the heads be added (I think I read somewhere that block revisions may be needed to sort the vibration problem - having said that, a new block is not a small thing, and the new heads and combustion may change the vibration characteristics entirely - is that right ?).
Re: Honda Power Unit
Posted: 05 May 2017, 11:35
by f1rules
but arent mclaren honda exactly running the ice at higher rpm ranges for, according to rumors, to avoid vibrations?, if so then that would actually be in the correct range according to wazari?
Re: Honda Power Unit
Posted: 05 May 2017, 12:42
by etusch
bigblue wrote: ↑05 May 2017, 11:27
Craigy wrote: ↑05 May 2017, 10:59
bigblue wrote: ↑05 May 2017, 10:32
Silverstone / Spa seems a long way off...
70 days. In the scheme of bringing a PU together, that's a blink of an eye.
I know, just there's always a need for some major revamp ... just feeling frustrated. I know nothing about designing engines but appreciate the complexities must be horrendous. Wonder if a revised block, or whatever's required to fix vibrations, can arrive before the new heads and then the heads be added (I think I read somewhere that block revisions may be needed to sort the vibration problem - having said that, a new block is not a small thing, and the new heads and combustion may change the vibration characteristics entirely - is that right ?).
Will new Block fit with current head? Journalists and F1 analist talking from stomac I think especially after wazari san's comment
Re: Honda Power Unit
Posted: 05 May 2017, 13:17
by sosic2121
Tommy Cookers wrote: ↑05 May 2017, 10:56
it's interesting to me that Wazari asks here the question that I asked 5 years ago - why not design around systematically higher rpm ?
eg I suggested that 13000-14800 rpm had some advantages over 10500-12100
mainly 'boost' pressure would be lower ie the supercharging power reduced in greater proportion (eg 23000 would be NA)
the recoverable energy is at least the same at this lower boost
and much less ES energy is used in 'spooling up'
ok at that time I was assuming a mildly lean AFR not very lean
clearly if the very lean TJI or similar suffers at these higher rpm then higher rpm is not on
So higher rpm allows Honda to have higher CR to gain efficiency?
Re: Honda Power Unit
Posted: 05 May 2017, 13:32
by GoranF1
by Spa/Silvestone Alonso will sign a contract whit another team....i know this is Honda PU thread, just saying.
Re: Honda Power Unit
Posted: 05 May 2017, 13:34
by godlameroso
trinidefender wrote: ↑05 May 2017, 06:43
Singabule wrote: ↑05 May 2017, 01:33
Wazari wrote: ↑05 May 2017, 01:03
Hi all! Since I have received some inquiries and have ignored almost all of you (sorry) I am taking the lazy route and will try and answer most of your questions in one post. I have not stayed current with this thread so if I'm repeating some things or posting something no longer relevant, I apologize in advance.
Yes I am disappointed and anticipated many issues but not to this extent. Yes the compressor is out of the "V" and in front. Yes the MGU-H is in the "V" and slightly lower than the previous PU as is the MGU-K. There were 3 combustion process designs decided upon and with strong advice from outside consultants this current spec was built. The next spec will be "our team's" process/design which obviously I am biased towards. All 3 concepts/designs were "in-house" designs. Just to clarify Honda is not opposed to "outside" help and consultants; it is welcomed. Getting outside help is another matter. A new head, pistons are supposed to be implemented soon.
Yes I am enjoying retirement again. I am mentally at peace. I was asked if I would consider working in the UK for 10 months and I thought about it for 5 seconds and then got mad at myself for wasting 5 seconds.
Food for thought: What if the new PU was expected to run at 1,500 RPM's on average higher than the competition and was actually designed to be more efficient at the higher RPM's? What if??? However certain vibration issues occurred at the higher RPM's??? Just speculation.........of course. Think about the extremely high CR and its relationship to RPM's. Also would you rather have your ICE powering your turbine/MGU-H at 10,500 or 12,250 RPM's if the consumption rate was the same? Just thinking while typing.
Again thanks for all your inquiries. I am fine and enjoying life. The season isn't over and I'm still optimistic for a big turn around Silverstone/SPA.
Thank you Wazari to visit this forum one more time, i hope you not retire from this forum as well..
. Compression is limited to 1:18, and honda's higher rpm should waste more energy through parasitic loss and Compression loss. I cant imagine how to archive better efficiency at higher rpm unless boost is limited by regulation too. At extremely high rpm, easier to minimize detonation, so at lower rpm honda engine is always at big risk of detonation, and lower boost is expected to mitigate such risk. However, this also lead to peaky nature of power delivery and bad to drivability so MCL slide everywhere. The Deployment from K is not perfect too, because of unmatured software because of Last minute engine Development. Pretty big task from honda to improve drivability imo than outright power.
There are a few things. Camshaft timing is one, especially if a pre-chamber is used then I suspect that camshaft timing may be critical to get proper filling of the prechamber.
Secondly there is piston ring tension. Higher tension rings mean lower blow by with the sacrifice being higher friction levels (this of course being a very general statement). By selecting slightly lower ring tension values then there will be less mechanical friction and power loss at higher rpm with the sacrifice being a little more cylinder pressure loss at lower rpms. Again these are very general statements.
Just food for thought, I can imagine that others can add other factors.
Does not ring tension and sealing comes directly from combustion pressure? Top rings have a taper facing the groove, and when combustion pressure travels down the taper allows combustion gases to push the ring outward creating the seal.
Re: Honda Power Unit
Posted: 05 May 2017, 13:34
by 63l8qrrfy6
I think wazari is hinting at the fact that higher piston speeds raise the knock limit.
It was said that v8 engines did not knock and CR was only limited geometrically.
I think frictional losses are to some extent cancelled out by less heat loss due to faster combustion. So maybe thermal efficiency does not improve overall but power output does.
Re: Honda Power Unit
Posted: 05 May 2017, 13:36
by 63l8qrrfy6
godlameroso wrote: ↑05 May 2017, 13:34
trinidefender wrote: ↑05 May 2017, 06:43
Singabule wrote: ↑05 May 2017, 01:33
Thank you Wazari to visit this forum one more time, i hope you not retire from this forum as well..
. Compression is limited to 1:18, and honda's higher rpm should waste more energy through parasitic loss and Compression loss. I cant imagine how to archive better efficiency at higher rpm unless boost is limited by regulation too. At extremely high rpm, easier to minimize detonation, so at lower rpm honda engine is always at big risk of detonation, and lower boost is expected to mitigate such risk. However, this also lead to peaky nature of power delivery and bad to drivability so MCL slide everywhere. The Deployment from K is not perfect too, because of unmatured software because of Last minute engine Development. Pretty big task from honda to improve drivability imo than outright power.
There are a few things. Camshaft timing is one, especially if a pre-chamber is used then I suspect that camshaft timing may be critical to get proper filling of the prechamber.
Secondly there is piston ring tension. Higher tension rings mean lower blow by with the sacrifice being higher friction levels (this of course being a very general statement). By selecting slightly lower ring tension values then there will be less mechanical friction and power loss at higher rpm with the sacrifice being a little more cylinder pressure loss at lower rpms. Again these are very general statements.
Just food for thought, I can imagine that others can add other factors.
Does not ring tension and sealing comes directly from combustion pressure? Top rings have a taper facing the groove, and when combustion pressure travels down the taper allows combustion gases to push the ring outward creating the seal.
It does for the power stroke, for the other 3 cycles however it is dominanted by tension as the rings are not energized to the same extent.
Re: Honda Power Unit
Posted: 05 May 2017, 13:39
by dren
Tommy Cookers wrote: ↑05 May 2017, 10:56
it's interesting to me that Wazari asks here the question that I asked 5 years ago - why not design around systematically higher rpm ?
eg I suggested that 13000-14800 rpm had some advantages over 10500-12100
mainly 'boost' pressure would be lower ie the supercharging power reduced in greater proportion (eg 23000 would be NA)
the recoverable energy is at least the same at this lower boost
and much less ES energy is used in 'spooling up'
ok at that time I was assuming a mildly lean AFR not very lean
clearly if the very lean TJI or similar suffers at these higher rpm then higher rpm is not on
I actually remember the discussion; doesn't seem that long ago! Less boost demand with similar MGUH recovery would certainly be more efficient? Not sure how mechanical losses look between the lower boost and increase in piston action.
He seems to suggest the vibration issues are at where the design operating rpm is.
I haven't payed attention to on-boards of RPM metering. Can anyone share the RPMs the PUs are running down the straights?
Re: Honda Power Unit
Posted: 05 May 2017, 13:40
by godlameroso
GoranF1 wrote: ↑05 May 2017, 13:32
by Spa/Silvestone Alonso will sign a contract whit another team....i know this is Honda PU thread, just saying.
That would be when teams time their introduction of their 3rd power unit if following the regulations.
And to Mr.Flap why would cylinder sealing matter at any point other than during combustion itself? Would it not add to pumping losses?
Re: Honda Power Unit
Posted: 05 May 2017, 14:13
by dren
Mudflap wrote: ↑05 May 2017, 13:34
I think wazari is hinting at the fact that higher piston speeds raise the knock limit.
It was said that v8 engines did not knock and CR was only limited geometrically.
Less time spent at said compression?
Re: Honda Power Unit
Posted: 05 May 2017, 14:19
by restless
Wazari wrote: ↑05 May 2017, 01:03
Just to clarify Honda is not opposed to "outside" help and consultants; it is welcomed. Getting outside help is another matter.
Thanks, but... can you clarify... the line above seems to contradict itself
Re: Honda Power Unit
Posted: 05 May 2017, 14:21
by flexcon
restless wrote: ↑05 May 2017, 14:19
Wazari wrote: ↑05 May 2017, 01:03
Just to clarify Honda is not opposed to "outside" help and consultants; it is welcomed. Getting outside help is another matter.
Thanks, but... can you clarify... the line above seems to contradict itself
Getting someone to help them is another matter I think they meant....
Re: Honda Power Unit
Posted: 05 May 2017, 14:22
by Joseki
Fascinating how every time the Honda PU is having problems is because they tried something different from the others and failed miserably.
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