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Re: Honda Power Unit
Posted: 29 Aug 2017, 11:57
by taperoo2k
One of two things will happen -
1. Honda will make a moderate improvement, but that will be seen as a failure in the press.
2. Honda makes significant gains and the press get giddy, hype up 2018.
I do wish people would stop obsessing over update y will bring x amount of horse power. Until they address the issues with the ERS and ICE, the HP potential will remain just out of reach. It looks like Honda is getting to grips with it's various issues. I wouldn't expect too much out of Spec 4 at Monza though. Seems more like it's aimed at ensuring McLaren do well at less power sensitive tracks in September, leading to a bigger update.
Re: Honda Power Unit
Posted: 29 Aug 2017, 12:14
by Postmoe
Wazari wrote: ↑29 Aug 2017, 03:15
IMO, two main issues still remain, ERS system management and ICE fuel efficiency.
How come they still have ERS management issues? Shouldn't they have good experience already after three years?
Re: Honda Power Unit
Posted: 29 Aug 2017, 12:26
by Del Boy
Postmoe wrote: ↑29 Aug 2017, 12:14
Wazari wrote: ↑29 Aug 2017, 03:15
IMO, two main issues still remain, ERS system management and ICE fuel efficiency.
How come they still have ERS management issues? Shouldn't they have good experience already after three years?
Until recently they missed the whole ERS concept. MGUH has to directly power the MGUK and Honda admitted they didn't plan for that with 2015 PU! Plus they tried an axial flow compressor that was a complete flop. Too much catching up to do!!!
Re: Honda Power Unit
Posted: 29 Aug 2017, 12:38
by Del Boy
Without wishing to get involved in the blowdown argument! I am interested in wastegates, I always thought wastegates were there to protect/limit the boost pressure and therefore only on the charged side, I was not aware of wastegates on the exhaust side. I believe road car turbo chargers send exhaust gas back through the engine to cool the charge and I suppose this acts as wastegatting.
Re: Honda Power Unit
Posted: 29 Aug 2017, 13:08
by hurril
Del Boy wrote: ↑29 Aug 2017, 12:38
Without wishing to get involved in the blowdown argument! I am interested in wastegates, I always thought wastegates were there to protect/limit the boost pressure and therefore only on the charged side, I was not aware of wastegates on the exhaust side. I believe road car turbo chargers send exhaust gas back through the engine to cool the charge and I suppose this acts as wastegatting.
None of this is true. The waste gates are always on the exhaust side. The charge side has pop off-valves. There's also no re-circulation of exhausts for the reason you describe here either; diesel engines can have an EGR-system though, for emission reasons.
Re: Honda Power Unit
Posted: 29 Aug 2017, 13:35
by godlameroso
Postmoe wrote: ↑29 Aug 2017, 12:14
Wazari wrote: ↑29 Aug 2017, 03:15
IMO, two main issues still remain, ERS system management and ICE fuel efficiency.
How come they still have ERS management issues? Shouldn't they have good experience already after three years?
ERS management is not the same as harvesting potential, I'd say it has more to do with deployment and recovery strategies, mapping. Better energy management, that sort of thing.
Re: Honda Power Unit
Posted: 29 Aug 2017, 13:55
by Tommy Cookers
[quote=Pedrohf]What you call "blowdown energy", are pressure waves created when the exhaust valves open or close. If the wastegate is open, they dont go through the turbine, they simply dissipate and dont do any work.
Turbines are powered by both energy, pressure, mass and heat from the exhaust gases and pulses from valve opening and closing. If the wastegate valve is open, that pressure wave (which has less energy than energy gases), goes through the wastegate, not the turbine.[/quote]
saying turbine energy (under blowdown/wastegating conditions) was a trickle I meant c. 25% (of exhaust + 'pulses') still goes through the turbine
Pedrohf says above that no 'pulse' (pressure wave) energy goes through the turbine
ie the wastegate drops this pulse/pressure wave notionally to ambient pressure (1 bar)
given that the peak of the pulse/pressure wave is at least 12 bar how could wastegate cross-sectional area etc be enough to drop this to 1 bar ?
and this large csa would be larger than needed for the rest of the cycle ? and would serve no purpose
wastegate action might allow more than 25% of the pulse/pressure wave energy to the turbine (without raising mean exhaust pressure above 1 bar)
50% (or 70% ?) would be priceless in qually
surely Mercedes have been doing this for years ?
Re: Honda Power Unit
Posted: 29 Aug 2017, 15:08
by Del Boy
hurril wrote: ↑29 Aug 2017, 13:08
Del Boy wrote: ↑29 Aug 2017, 12:38
Without wishing to get involved in the blowdown argument! I am interested in wastegates, I always thought wastegates were there to protect/limit the boost pressure and therefore only on the charged side, I was not aware of wastegates on the exhaust side. I believe road car turbo chargers send exhaust gas back through the engine to cool the charge and I suppose this acts as wastegatting.
None of this is true. The waste gates are always on the exhaust side. The charge side has pop off-valves. There's also no re-circulation of exhausts for the reason you describe here either; diesel engines can have an EGR-system though, for emission reasons.
Thank you for the waste gate explanation. It was EGR system I was talking about as I had to have the valve replaced recently and Ford told me for cooling. Emissions makes more sense.
Re: Honda Power Unit
Posted: 29 Aug 2017, 15:41
by Pedrohf
Tommy Cookers wrote: ↑29 Aug 2017, 13:55
Pedrohf wrote:What you call "blowdown energy", are pressure waves created when the exhaust valves open or close. If the wastegate is open, they dont go through the turbine, they simply dissipate and dont do any work.
Turbines are powered by both energy, pressure, mass and heat from the exhaust gases and pulses from valve opening and closing. If the wastegate valve is open, that pressure wave (which has less energy than energy gases), goes through the wastegate, not the turbine.
saying turbine energy (under blowdown/wastegating conditions) was a trickle I meant c. 25% (of exhaust + 'pulses') still goes through the turbine
Pedrohf says above that no 'pulse' (pressure wave) energy goes through the turbine
ie the wastegate drops this pulse/pressure wave notionally to ambient pressure (1 bar)
given that the peak of the pulse/pressure wave is at least 12 bar how could wastegate cross-sectional area etc be enough to drop this to 1 bar ?
and this large csa would be larger than needed for the rest of the cycle ? and would serve no purpose
wastegate action might allow more than 25% of the pulse/pressure wave energy to the turbine (without raising mean exhaust pressure above 1 bar)
50% (or 70% ?) would be priceless in qually
surely Mercedes have been doing this for years ?
That's completely different from the "electric supercharger" powered by the MGU-K and some magical "blowdown energy", nonsense bullshit from godlameroso.
Still, this is only useful on qualifying mode, or racing mode if your harvest strategy is flawed / ERS gets full.
Even pretending the pulse is 12bar, its only a brief pressure pulse, its not enough to drive 50% of the compressor. And as soon it reaches a plenum (junction with other pipes, turbo, or wastegate), it dissipates or is reflected back (negative pressure) to the valve.
And always, always, if the wastegate is not enough to route all the gases around the turbine, you will have backpressure, even if the turbine is powered only by this pulses.
Turbines act as a buffer for this pulses.
Re: Honda Power Unit
Posted: 29 Aug 2017, 16:40
by ArcticWolfie
hurril wrote: ↑29 Aug 2017, 13:08
Del Boy wrote: ↑29 Aug 2017, 12:38
Without wishing to get involved in the blowdown argument! I am interested in wastegates, I always thought wastegates were there to protect/limit the boost pressure and therefore only on the charged side, I was not aware of wastegates on the exhaust side. I believe road car turbo chargers send exhaust gas back through the engine to cool the charge and I suppose this acts as wastegatting.
None of this is true. The waste gates are always on the exhaust side. The charge side has pop off-valves. There's also no re-circulation of exhausts for the reason you describe here either; diesel engines can have an EGR-system though, for emission reasons.
Petrol cars have an EGR system as well, but I believe they add a cooling system on the diesel ones.
Re: Honda Power Unit
Posted: 29 Aug 2017, 17:14
by GoranF1
Spec 3.5 was worth 5BHP.
Re: Honda Power Unit
Posted: 29 Aug 2017, 17:22
by Postmoe
godlameroso wrote: ↑29 Aug 2017, 13:35
Postmoe wrote: ↑29 Aug 2017, 12:14
Wazari wrote: ↑29 Aug 2017, 03:15
IMO, two main issues still remain, ERS system management and ICE fuel efficiency.
How come they still have ERS management issues? Shouldn't they have good experience already after three years?
ERS management is not the same as harvesting potential, I'd say it has more to do with deployment and recovery strategies, mapping. Better energy management, that sort of thing.
Re: Honda Power Unit
Posted: 29 Aug 2017, 17:23
by Postmoe
godlameroso wrote: ↑29 Aug 2017, 13:35
Postmoe wrote: ↑29 Aug 2017, 12:14
Wazari wrote: ↑29 Aug 2017, 03:15
IMO, two main issues still remain, ERS system management and ICE fuel efficiency.
How come they still have ERS management issues? Shouldn't they have good experience already after three years?
ERS management is not the same as harvesting potential, I'd say it has more to do with deployment and recovery strategies, mapping. Better energy management, that sort of thing.
That is exactly why I am surprised. It should be more data-driven than anything.
Re: Honda Power Unit
Posted: 29 Aug 2017, 17:37
by ziggy
Del Boy wrote: ↑29 Aug 2017, 12:26
Postmoe wrote: ↑29 Aug 2017, 12:14
Wazari wrote: ↑29 Aug 2017, 03:15
IMO, two main issues still remain, ERS system management and ICE fuel efficiency.
How come they still have ERS management issues? Shouldn't they have good experience already after three years?
Until recently they missed the whole ERS concept. MGUH has to directly power the MGUK and Honda admitted they didn't plan for that with 2015 PU! Plus they tried an axial flow compressor that was a complete flop. Too much catching up to do!!!
I'm speechless. This is not embarrassing anymore, it's just sad. Very sad.
Re: Honda Power Unit
Posted: 29 Aug 2017, 18:35
by godlameroso
Pedrohf wrote:
Still, this is only useful on qualifying mode, or racing mode
What other modes are there?
Pedrohf wrote:
if your harvest strategy is flawed / ERS gets full.
What?
Pedrohf wrote:
Even pretending the pulse is 12bar, its only a brief pressure pulse, its not enough to drive 50% of the compressor.
There are 6 pulses per engine cycle all contributing, you're neglecting that there's roughly 400kw of potential energy in the exhaust.
Pedrohf wrote:
And as soon it reaches a plenum (junction with other pipes, turbo, or wastegate), it dissipates or is reflected back (negative pressure) to the valve.
Only partially, depending on the obstruction to the pressure wave.
Pedrohf wrote:
And always, always, if the wastegate is not enough to route all the gases around the turbine, you will have backpressure, even if the turbine is powered only by this pulses.
Turbines act as a buffer for this pulses.
The turbine is powered by the pressure increase from combustion exhaust gases, and the MGU-H. I'm going to assume English isn't your first language, as to why you're acting like an ass, maybe you had a bad upbringing, maybe you're just a troll.