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YICS observation

Started by Coil Coyle, January 27, 2009, 06:21:20 AM

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Jirik

Volumes from my measurement are a little different: front 80 ml, rear 78 ml. I measured it with water on separate halves without hoses.

The Prophet of Doom

I bought a graduated syringe today and got the same as Jirik within a ml or two.  I guess they are more accurate than baking spoons.
Post your cool YICS replacement designs here.  Winner gets everlasting fame and fortune.

Rikugun

Great info and pictures Jirik. So how much does water tension affect the results!?  :P

I also found fret nut's theory interesting. Obviously no way to verify but I could see it happening.

Looking through some old posts I think Jasonm might have had some dyno results posted. There was a link I assume to a document but it's no longer viable. Anyone have a copy to share here?
It is far better to grasp the universe as it really is then to persist in delusion, however satisfying or reassuring.  Carl Sagan

skucera

#23
I wonder if the wedge shape of the chambers is important?  Yamaha having so much experience with sonic wave propagation in exhaust pipes and combustion chambers, I wonder if the flow of gasses into and out of the YICS chambers pulses in and out, and results in some extra charge swirl versus a chamber of another shape?  If so, elasticity of the plastic that the chamber is made from might be important too.

Does anyone here have experience making musical instruments?  If so, your insights would be much more instructive than my casual speculations....

Scott

cvincer


Y'all remember this from  tymyth79 ?

fret not

Yamaha engineers have been at the forefront of making motors go fast for decades.  They are , or were, at the top of the game in the most industrial sense as they made possible the domination of FIM world championship for many years in many classes, and they are still working at it in MotoGP.  If there is a viable concept in the YICS system then I'm sure they have milked it for all it's worth.  Do you see any of this technology in current vehicles?

As for the assumed association with tuning motors and musical instruments, the Yamaha logo is three tuning forks and they do have a long history of making musical instruments.  I have a tuning fork and I know how to use it, and I also have a slide rule. 

I remember reading "technical articles" in the motorcycle magazines in the 60s where porting and exhaust designs were postulating how the gasses swirled and did their dance to make more power.  The reality is the flow of the gasses is more complex and less predictable than first imagined, though the engineers have figured out how to make a lot more power from a given displacement than I ever expected.  Those MotoGP bikes are making 250 horse power from 1000cc!  The Moto3 250cc singles are making 55HP! 
Retired, on the downhill slide. . . . . . . . still feels like going uphill!

The Prophet of Doom

Quote from: Rikugun on October 08, 2014, 08:35:28 AM
Great info and pictures Jirik. So how much does water tension affect the results!?  :P

I also found fret nut's theory interesting. Obviously no way to verify but I could see it happening.

Looking through some old posts I think Jasonm might have had some dyno results posted. There was a link I assume to a document but it's no longer viable. Anyone have a copy to share here?
I think this might be the one you were thinking of Rikugun.  A marginal power difference, but then this was touted by Yamaha as a fuel saving device, not a power increasing device.



fret not

Maybe that chart shows actual results of an authentic dyno test, and maybe it's only "marketing".  Either way unless an independent source does a dyno test we may never know.  Since the difference in performance results are subtle I guess it doesn't much matter.
Retired, on the downhill slide. . . . . . . . still feels like going uphill!

Extent

That dyno chart was made by an engineering student team using an XZ powerplant in a project of some kind, the source isn't really any kind of mystery.
Rider1>No wonder, the Daytona has very sharp steering and aggressive geometry.  It's a very difficult bike for a new rider.
Rider2>Well it has different geometry now.

Rikugun

I'd be more impressed if the chart was from Yamaha and with new bikes. My brother was an engineering student once which did not make him an expert with carbs, bike carbs and certainly not Vision carbs. Depending on the tested carb and engine state of tune, the numbers may or may not be valid.
It is far better to grasp the universe as it really is then to persist in delusion, however satisfying or reassuring.  Carl Sagan

The Prophet of Doom

Measuring a fuel savings/ emissions reduction device on a dyno is a bit retarded.  A fuel flow meter and an EGA would be more appropriate.  Nice to know that is doesn't appear to rob power though.