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What controls the boost?

22637 Views 57 Replies 13 Participants Last post by  Turtle1000, 
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I believe I've read that the supercharger will have two drive speeds. Does anyone have info on how the drive ratio will be changed between the two speeds?
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F
Probably an electro-hydraulic actuator something like a Moog valve.
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Greenguy
2befast said:
I believe I've read that the supercharger will have two drive speeds. Does anyone have info on how the drive ratio will be changed between the two speeds?
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I have read that too but it was not from Kawasaki and from what I have seen yet there is nothing showing me that there is a two speed drive system for the supercharger. It is a direct drive chaine with a simple planetary gear box so I suspect that the super charger pressure will be control by a electrovalve control by the ECU via a pressure sensor.
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Bazza
ECU contains the 'knowledge', impeller contains the contents

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F
There is a plate not shown here that fits over the planets and sun gears that will accommodate the shift. No doubt that oil pressure will rotate this mount plate. If you look at the unit you will see a port at 2:00 o'clock which will be pressurized oil, probably used to engage/disengage the planet gears. If it was a drain/return line it would be at the bottom of the casting. Returning oil will exit the cluster by gravity back down to the sump.

This is the same basic principle as Kaw uses to run their variable valve timing on the 14 Concours (and Ducs version of the same).

Very long wheelies might allow some oil to accumulate inside the cluster.

The locating pins next to the mount screws suggest a plate which will see a fair amount of rotational torque hence the pins to take the stress instead of very small screws cut into soft aluminum.
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P
I highly doubt it's that complicated. I imagine it is just a controllable bypass from intake to pressurized box.
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pieter3d said:
I highly doubt it's that complicated. I imagine it is just a controllable bypass from intake to pressurized box.
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No..that's why it has 3 planet gears = 2 speeds.
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Fretka said:
No..that's why it has 3 planet gears = 2 speeds.
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That would require a planet carrier. Not present in the pics. I saw this thing in person at a motorcycle show, including the cutaway engine.
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SilverbirdH2
Doesn't the Kawasaki specs say it has two speeds?Which are governed by the load?Something like that anyway....I'm no tech.Like Bazza said...totally dictated by the ECU...seamless changing...probably not something anyone would notice...I mean...adjusting all the time throughout the rev range?

I'm not knowledgeable with Turbo and such...but doesn't a turbo have a fixed amount of boost...???This thing apparently is programmed to offer exactly the correct amount of boost at any rpm...yes?I mean...to accomplish the Kawasaki parameters for power output...which is gonna be ungodly;)I'm guessing here...sorry if I sound ignorant...just trying to learn.

I keep going back to that video of that guy on the dyno...the way he's powering up and shifting and all...honestly...I can't seem to grasp HOW a guy on the street could RIDE the bike this way.And that's on a dyno.Seems like the bike would literally be on one wheel if it weren't for the electronics kicking in.That one guy at Suzuka...he wasn't riding full on...no way...

Does this have anything to do with the original post?Probably not....just throwing out my thoughts here...I don't want to muddle up things...
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OzBooster
Turbos have a wide range of boost available , its up to the controller used either a basic single level wastegate or a more complicated electronic control of this wastegate to determine the end result

Guys like Fretka with boosted bike experiance already know just how much different this H2 will be from a NA bike to ride (insert devil symbol)
only real difference i have seen between currently available aftermarket supercharged bikes and turbo bikes for a 300hp odd system is the way the power is delivered
supercharger has a very flat power curve , turbo has more mid range ,
supercharger would be easier to control , and current systems have the ability to overdrive the supercharger and bleed off unwanted air to control the output , where you have to bleed off the exhaust on a turbo bike (wastegate)

The press release say 2 speed for the h2 supercharger , seems complicated , but would give better heat control of the intake charge to not beat the air up too much just to release some
time will tell ;)
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P
I just read the press release, doesn't say anything about a 2-speed supercharger.
From the PDF: http://www.kawasaki.com/Press/Release/2015-Ninja-H2

The gear train increases the impeller speed up to 9.2x the crank speed (1.15x step gear with an 8x planetary gear). This means at a maximum engine speed of approximately 14,000rpm, the impeller shaft is spinning at almost 130,000rpm.
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P
Wikipedia mentions a 2-speed supercharger, but only cites this cycleworld article as source, which is just making guesses based on earlier patent application leaks.
Those patent leaks, here and here, make no mention of such a system. In fact, the patent specifically talks about a relief valve, aka a way to regulate pressure by bleeding some of the air off.
a relief valve (68) that adjusts the air pressure in the supercharged air duct (62); The exhaust outlet (68b) of the relief valve (68) is contained in the air cleaner (36).
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OzBooster
Cant remember where i read it, thought it was on the Kawasaki release but may have been the cycle world article

i agree a pmw of a solenoid controlling a type of bov or electronic stepper controlling a vent bit like an idle speed control would both be more what the electronic controls of the current age are more suited to than a mechanical device , again time will tell when something more definite is released or we can actually see one in use
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pieter3d said:
That would require a planet carrier. Not present in the pics. I saw this thing in person at a motorcycle show, including the cutaway engine.
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If you look closely the planet gear at the upper right is not in mesh with the sun gear. Pics are not showing the mounting plate because it's ugly and people want to see gears more than a flat plate with an actuator attached.
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I'm sittin here looking at this super and I can't figure out how they made it a 2 speed impeller. I know how planetary gears work but I'll be damned if I can figure how they did it.
It seems to me I remember someone saying it was 2 speed.
Most probably wrong but they may be able to do it by controlling movement of the ring gear.

Anyone got any ideas?
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OzBooster
When i go back and look at the references i wonder if there was confusion over the
"9.2x speed increase" and "Step up gear" mentioned
it was the cycle world reference with comment about ww2 superchargers that stuck in my mind , recognised it as soon as i googled h2r 2 speed
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P
It's not a 2 speed.
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Turtle1000
Yes it just spins at 9.2 times the engines' rpm. I believe the waste gate or whatever term you guys prefer was important because with a centrifugal Super charger being actually connected to engine by gearing it causes an interesting problem... It creates boost when your off the gas, or at least that's how I interpreted it. So the waste gate can bleed the boost until you'd appreciate throttle open. (Lol or if your me on that thing it'll be more like gingerly opening it 1/32 of an inch)
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F
I guess at this point we will have to believe your right, no compound super drive.

I have become cross-eyed looking at every pic I can find and these are all (I think) computer gen. pics and show different incomplete illustrations. One early showed these planets with some teeth missing suggesting indexing. another shows the unit with only the gear cluster and no ring gears, and yet another with diff planet shaft-ends, etc..

No big deal but either way you are throwing away energy, in this case out of the airbox by way of a blow-off valve.
May even be lighter, less complicated this way.

I give up... when one of you gets your bike (maybe Christmas morning) let us know, (when you learn how to speak again)!
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Greenguy
pieter3d said:
Wikipedia mentions a 2-speed supercharger, but only cites this cycleworld article as source, which is just making guesses based on earlier patent application leaks.
Those patent leaks, here and here, make no mention of such a system. In fact, the patent specifically talks about a relief valve, aka a way to regulate pressure by bleeding some of the air off.
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That exactly what I thought. It would be way to complicated and subject to failure to do a systeme that change the ratio each time you cross a dedicated RPM and over that it would need to be different from the H2R and H2. A lot easyer and cheaper to work with a electrovalve (wastegate) and the good new is that a simple change in the parameter in the ECU will let you change the desire output pressure at a given RPM even a third party company could altered the voltage from the pressure sensor and the electrovalve to obtain a desire output pressure from the supercharger exactly the same way they do with fuel injector.
I am sure Kawasaki know that and that why they did produce the H2R, to show us the capability of the H2 but couldn't produce a 300 HP street legal motorcycle and by this way they just give us the recipe to get near there.
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