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Re: Honda Power Unit
Posted: 15 Aug 2017, 04:06
by godlameroso
Powerslide wrote: ↑15 Aug 2017, 03:41
just out of curiousity, is honda's general lack of interest in turbulent jet injection technology setting them back? what about all that oil burning voodoo stuff that ferrari and mercedes-amg used before banned, that surely must have caught honda out
TJI is a Ferrari thing, I'm sure Honda is using lean burn tech just not necessarily TJI but rather their own take on it.
Re: Honda Power Unit
Posted: 15 Aug 2017, 04:32
by godlameroso
gruntguru wrote: ↑15 Aug 2017, 02:05
godlameroso wrote: ↑15 Aug 2017, 00:54
Fuel return is an archaic method of fuel pressure regulation, most new cars use returnless systems without a vacuum assisted FPR. As for the pump rails and lines, they'd hold around .5 liters max. I'm sure that value increases with acummulators. The fuel tank isn't very far away from the engine either, if they're heating the fuel, they'd probably want to keep the lines as short as possible to maintain more accurate control over fuel temps.
Road cars running low fuel pressure (<5 bar) need a return-loop system when converted to forced induction. The fuel pressure needs to be maintained at a constant level above boost pressure to keep injector flow constant at all values of MAP and running a boost line from the engine to a pressure reg at the back of the car is laggy.
High pressure DI systems like F1 usually have electronically variable fuel pressure to increase the turn down ratio of the injectors.
Good thing the Honda jalopies have the regulator right on the fuel rail, it's almost like they wanted you to boost them.
Re: Honda Power Unit
Posted: 15 Aug 2017, 10:13
by stevesingo
godlameroso wrote: ↑14 Aug 2017, 13:31
I think they're burning 2 types of fuel, you're allowed 2 types per event, and are allowed to store 2 liters outside the main fuel tank. You have a low reactivity fuel for the main chamber (What you keep in the main fuel bladder). Then you have a higher reactivity fuel for the pre-chamber. 2 liters is enough as the pre-chamber is only a fraction of the volume of the main chamber. A little HRF goes into the pre-chamber, some LRF goes into the main chamber all precisely measured at a very specific cylinder timing, and boom lots of power at a very efficient level. Meanwhile what you smell is partly burned cetane improver of the HRF and some inadvertent oil burning.
Would that not need two injectors?
Re: Honda Power Unit
Posted: 15 Aug 2017, 13:31
by diffuser
stevesingo wrote: ↑15 Aug 2017, 10:13
godlameroso wrote: ↑14 Aug 2017, 13:31
I think they're burning 2 types of fuel, you're allowed 2 types per event, and are allowed to store 2 liters outside the main fuel tank. You have a low reactivity fuel for the main chamber (What you keep in the main fuel bladder). Then you have a higher reactivity fuel for the pre-chamber. 2 liters is enough as the pre-chamber is only a fraction of the volume of the main chamber. A little HRF goes into the pre-chamber, some LRF goes into the main chamber all precisely measured at a very specific cylinder timing, and boom lots of power at a very efficient level. Meanwhile what you smell is partly burned cetane improver of the HRF and some inadvertent oil burning.
Would that not need two injectors?
Good point! Only 1 injector/Cylinder is allowed.
Re: Honda Power Unit
Posted: 15 Aug 2017, 13:36
by godlameroso
You could do it with one very complex injector. Don't know if it would fit into FIA's allowed parts bin.
Re: Honda Power Unit
Posted: 15 Aug 2017, 14:49
by etusch
godlameroso wrote: ↑15 Aug 2017, 13:36
You could do it with one very complex injector. Don't know if it would fit into FIA's allowed parts bin.
I think there is some clever design like double deck diffuser passes rule check
Re: Honda Power Unit
Posted: 15 Aug 2017, 14:56
by stevesingo
godlameroso wrote: ↑15 Aug 2017, 13:36
You could do it with one very complex injector. Don't know if it would fit into FIA's allowed parts bin.
And two fuel supply systems (LP pump, HP Pump, lines, sensors and control systems)!
Re: Honda Power Unit
Posted: 15 Aug 2017, 16:33
by GoranF1
Re: Honda Power Unit
Posted: 15 Aug 2017, 17:50
by diffuser
No information in there on where Racer met with Hasegawa. Probably just a rehash from Hungry.
Re: Honda Power Unit
Posted: 15 Aug 2017, 17:56
by GoranF1
Definitely we will prepare another two steps, but it could be three," Hasegawa told RACER
diffuser wrote: ↑15 Aug 2017, 17:50
No information in there on where Racer met with Hasegawa. Probably just a rehash from Hungry.
Re: Honda Power Unit
Posted: 15 Aug 2017, 20:39
by dren
Powerslide wrote: ↑15 Aug 2017, 03:41
just out of curiousity, is honda's general lack of interest in turbulent jet injection technology setting them back? what about all that oil burning voodoo stuff that ferrari and mercedes-amg used before banned, that surely must have caught honda out
Honda had interest in it 40 years ago with the CVCC in the Civic.
Re: Honda Power Unit
Posted: 15 Aug 2017, 23:21
by PhillipM
Sounds like there's a new lubricant spec to go with the next MGU-H change (maybe that's where the experience/info frm the aero side came from)
Re: Honda Power Unit
Posted: 16 Aug 2017, 02:20
by dren
The translated article insinuated it was dynamic balancing.
Re: Honda Power Unit
Posted: 16 Aug 2017, 07:01
by rscsr
dren wrote: ↑16 Aug 2017, 02:20
The translated article insinuated it was dynamic balancing.
That can't be right. Is there really anyone who doesn't use dynamic balancing? Especially for a part that rotates at such a high speed dynamic balancing should be standard practice. I don't think there has ever been any rotating part that hasn't been dynamically balanced where I worked (mainly heavy engineering in the paper industry). Even every wheel on road cars gets dynamically balanced.
What I can imagine is that they maybe have been balancing the assembly at 2000rpm (or similar) and therefore wouldn't be accurate enough for operation at 125000rpm. And now they are balancing at 20000rpm+.
That also might explain that some MGU-H units seemed to work (maybe because they got the balancing good enough) and a lot have not.
Re: Honda Power Unit
Posted: 16 Aug 2017, 08:32
by rgava
I think it's not about the rotational speed during the dynamic balancing.
IMHO it's about the sensibility of the balancing equipment.
But more important for such a long shaft it's about multi plane balancing. If you are not able to detect the axial position of the unbalance your balancing mass will be offset axially creating a rotational couple which could destroy the bearings.