New R1 uses M1 firing intervals.

[Old Baldy]

Originally Posted by hubert

Decent article on soup from a while back , Big Bang By The Numbers

I remember reading this article. It's interesting stuff, and I thought that Yamaha's finding that the close-order I4 layout was the best overall design for traction and/or rider "connection" WITH the handling advantages of the short I4 motor, was enlightening. They certainly are getting the results they wished for, this year.

But, I have a question regarding this piece of the article below.....

"At BDC the piston, con rod and crank pin are in line and no torque can be applied to the crankshaft (in fact at top and bottom dead centres, the con rod is momentarily stationary and vertical). Now move through 90 degrees. The big end of the con rod together with the piston is moving quickly with lots of energy and is about to decelerate to a halt at TDC. That energy of motion (kinetic energy) has to go somewhere, and the only place it can go is into the crankshaft. So inertia torque is positive in that it is applied in the direction of rotation of the crank. On the down stroke, the converse is true. The lower part of the con rod together with the piston has to be rapidly accelerated from rest at TDC to a high velocity, which requires an input of energy. That removes energy from the crankshaft so here inertia torque acts against the direction of rotation."

.....I have problems visualizing the concept of the "intertia torque" being a "positive" torque after BDC, when the conrod big-end (and rod + piston) is being accelerated up towards TDC.

I see this as a torque reduction (negative) force against the crank direction, as the mass of the piston and conrod are resisting the crank's "desire" to rotate and shove them back up the bore to TDC. How can that be a positive force for the crank?

(just as there is a negative torque reaction after TDC, when the crank has to force the piston and rod to accelerate back down towards BDC (ignoring the power pulse actually does this under power).

Thoughts?

[Beinggodisgreat]

That is the ugliest thing i've ever seen...Im buying vintage from now on...

---------------- Now playing: Dream Theater - Lines in the Sand via FoxyTunes

[Busy Little Shop]

Originally Posted by Old Baldy

.....I have problems visualizing the concept of the "intertia torque" being a "positive" torque after BDC, when the conrod big-end (and rod + piston) is being accelerated up towards TDC.

Just think of it as the "virtual V4" at least that is what the press coined it
when Yamaha's Furusawa re invented the I4... There are 5 important steps
to get where they have gotten and they still not 100% satisfied... Rossi
himself tested 4 different engine configurations...

1 Yamaha started with their patented 5 valve head and standard 180º crank...

2 Yamaha scraps the 180º introduces the big bang firing order by firing
pairs of cylinders...

3 Yamaha scraps the big bang for an irregular firing order with two
combustions events close together followed by the other two spaced out more...

4 Yamaha spins the crankshaft backwards to offset the long I4
crankshafts gyroscopic procession and it's resistance to turning...

5 In an effort to make the I4 as narrow as possible Yamaha moved the
cam gear drive from the side of the wide block to up the back side of
the engine...

In conclusion the I4 has changed the most whereas the V4 has changed the least...

I predict someday Yamaha will build a V4...

[Busy Little Shop]

Originally Posted by Old Baldy

Won't make a difference to the actual power/torque production /powerband in itself, of course, UNLESS they changed the motor's tuning.

All the tuning in Christendom won't make the old 180º I4 pull like this new
firing order... but Baldy... you're still welcome to try...

[Old Baldy]

Originally Posted by Busy Little Shop

All the tuning in Christendom won't make the old 180º I4 pull like this new
firing order... but Baldy... you're still welcome to try...

Larry, you should try to rewrite automotive equations to explain how torque and the resultant HP is achieved by changing the angle of the cylinders, because it does not exist in any automotive theory or reference work. Perhaps you could help Furusawa build a new set of 2 or 4-cycle engine formulae for how torque and HP can now be calculated for ultra high RPM multi-cylinder motors, with the effects of the "intertia torque!"

Now, THAT would be impressive!

But.....why would Furusawa want to build a V4 against his own findings that the I4 is the best overall layout for MGP?

"Is this an inherent advantage of the 90-degree V4 engine? Yamaha think not, and will continue with the in-line engine which they regard as enabling them to build a shorter and therefore more nimble machine"

PS. If you could help answer my question on the "positive" inertia torque generated by the piston+rod on the crank after BDC, I'd appreciate it.

[XFBO]

If someone makes a low slung exhaust and it leads to a 20+# reduction in weight then I agree it will be greatly improved. But I dont wanna see photoshop I wanna see a real track version. It did sound pretty sick, will give'em props for that.

[Busy Little Shop]

Originally Posted by Old Baldy

But.....why would Furusawa want to build a V4 against his own findings that the I4 is the best overall layout for MGP?

Furusawa don't ride but Rossi does... he may think the I4 is best but Rossi is
on record stating he thinks the V4 is best... I think Yamaha should listen to
their star rider and over ride Furusawa...

[Old Baldy]

Originally Posted by Busy Little Shop

Furusawa don't ride but Rossi does... he may think the I4 is best but Rossi is
on record stating he thinks the V4 is best... I think Yamaha should listen to
their star rider and over ride Furusawa...

Old, past tense stuff, Larry.

You believe that Rossi signed to continue with the I4 Yamaha for the next coupla years against his own desire, and when the I4 Yamaha is dominating the constructors championship?

Rossi has shown that he can get whatever he wishes, in MGP, even splitting his team's tire choice down the middle and forcing a wall to be built between his own constructor's team in the pits.

I'll have some of what you must be smoking, Larry. It must be powerful stuff!

[Furious Styles]

Originally Posted by GAMBLER

she will clean up in track trim

Exactly what I was thinking. Who gives a shit about street trim when you do all your riding at the track?
Street is basically useless. All bikes get crashed and then street trim is a boat anchor or used for the latest colage.
Th biks looks like every other R1 Or the R7 of yester year.
In race trim its the shit, and thats what really matters. The only bike that looks like ass no matter what you put it in... is the Buell.

[Busy Little Shop]

Originally Posted by Old Baldy

Old, past tense stuff, Larry.

You believe that Rossi signed to continue with the I4 Yamaha for the next coupla years against his own desire, and when the I4 Yamaha is dominating the constructors championship?

Rossi signed because is super comfortable with his team... when Rossi says
and I quote "the V4 is the best way" it's because it has proven to be just as
agile but a hell of lot faster than his I4... there isn't a weak spot for Yamaha
to exploit except spin the M1s crank backwards to allow Rossi deeper dives
into the corner... but that trick cost another shaft to be used in the engine
which saps a reported 5HP...

[tmoneyr007]

Originally Posted by varium

Wow, 454lbs.

Interestingly, Yamaha has quoted a wet-weight figure for the R1 rather than the usual dry weight. If the quoted figure of 454 lbs is to be believed, the bike has lost about 10 lbs compared to the previous version.

2009 Yamaha R1 Unveiled! - Motorcycle.com

[tmoneyr007]

Originally Posted by GAMBLER

she will clean up in track trim

Where are the air duct inlets?

[UnpaintedHuffhines]

much respect to yam for putting out a wet number

even more if its accurate

i would think in track trim with a full ti underslung shorty you would be looking at 410ish

looks like a bike to me

[Ben710]

Originally Posted by tmoneyr007

Where are the air duct inlets?

Photoshopped away. They used to be next to the lights.

[simonkobe]

wonder how the headlight/intakes will affect aerodynamics.must be important if honda can base their whole bikes styling on how the frontal area is affected by cross winds etc(or maybe thats just BS!)

But im surprised.the front looks a bit unfinished and hacked together
But the rest looks great,especially the tail(i personally think they kept the underseat exhaust to cash in on the ducati craze at the moment.The droning engine noise and the extra vibration of an underseat will give salesmen something else to talk about maybe-the torque and feel of a twin with the power of a 4 cylinder blah blah...

But overall pretty exciting compared to the kawasaki and honda,technology wise.
But next year there will be the new aprilia and BMW.getting tough for the japanese!

I reckon magical racing should make a nice M1 replica seat unit,and get a top japanese maker(striker maybe!)to make a nice side outlet slip on(looks like it wont be too difficult!)

[sburns2421]

Originally Posted by Old Baldy

I remember reading this article. It's interesting stuff, and I thought that Yamaha's finding that the close-order I4 layout was the best overall design for traction and/or rider "connection" WITH the handling advantages of the short I4 motor, was enlightening. They certainly are getting the results they wished for, this year.

But, I have a question regarding this piece of the article below.....

"At BDC the piston, con rod and crank pin are in line and no torque can be applied to the crankshaft (in fact at top and bottom dead centres, the con rod is momentarily stationary and vertical). Now move through 90 degrees. The big end of the con rod together with the piston is moving quickly with lots of energy and is about to decelerate to a halt at TDC. That energy of motion (kinetic energy) has to go somewhere, and the only place it can go is into the crankshaft. So inertia torque is positive in that it is applied in the direction of rotation of the crank. On the down stroke, the converse is true. The lower part of the con rod together with the piston has to be rapidly accelerated from rest at TDC to a high velocity, which requires an input of energy. That removes energy from the crankshaft so here inertia torque acts against the direction of rotation."

.....I have problems visualizing the concept of the "intertia torque" being a "positive" torque after BDC, when the conrod big-end (and rod + piston) is being accelerated up towards TDC.

I see this as a torque reduction (negative) force against the crank direction, as the mass of the piston and conrod are resisting the crank's "desire" to rotate and shove them back up the bore to TDC. How can that be a positive force for the crank?

(just as there is a negative torque reaction after TDC, when the crank has to force the piston and rod to accelerate back down towards BDC (ignoring the power pulse actually does this under power).

Thoughts?

I had forgotten about the link provided (thanks BTW) and it explained a couple of questions I had regarding the whole scheme.

First, when I read the press release about the 2009 R1, I thought it was curious that they mentioned that it was much smoother. This didn't make sense purely from a balancing standpoint. Then in the third from last paragraph in the soup article is, "Of course the first law of engineering says you never get something for nothing and an irregular firing order means vibration that may require a balance shaft or heavier components to tame, thus losing you part of what you've just gained." So perhaps the R1 does feel smoother than conventional I-4's but that is due to external balancing (not the crankshaft).

Second, what I missed when I first read this article months ago was that combustion pressure is irrelevant. We are only talking now about the dynamics of the rotating mass in the engine. This is what I think is key to the entire explanation. In the past apparently manufacturers thought the interaction of the cylinders' reciprocating masses was negligible, while the torque pulses from combustion pressure dominated. For lower RPMs, apparrently this is the case. As revs rose though, the "flywheels" of the crank sections for each cylinder, even a lightweight racing crank, started to mask these combustion pressure torque pulses.

So if you think of each cylinder (a section of the crank, piston, and rod) as separate entities, what we can do is look at what the "crankshaft intertia torque" for each cylinder is, then add them together. Comparing a conventional I-4 to this one will be interesting.

The new R1 engine:
At any given position for cylinder 1, we know the position of each piston in the other three cylinders.
Cyl Crankshaft angle
1 0 90 180 270
2 90 180 270 0
3 180 270 0 90
4 270 0 90 180

So now lets assign an arbitrary positive or negative sign to each cylinder at each crank position, using the notation introduced in the soup article. Reference paragraph 6.
*Starting at 0 degrees, the piston/rod will be removing energy from the crank, so give it a minus (-)
*At 90 degrees, the piston starts to slow down and gives this energy back to the crank, so give it a plus (+)
*180 degrees the cycle repeats and the piston uses energy from the crank (-)
*At 270 the piston begins deccelerating again (+)

So now write the same table again
Cyl Energy into crank
1 - + - +
2 + - + -
3 - + - +
4 + - + -

If you sum each of these columns (the net effect on the crankshaft at any given time), you see that each column sums to zero.

If you were to re-write this table for a standard inline the difference is clear. For a crank that starts out at 0_180_180_0, you wind up with big fluctuations in this inertia torque, swapping from -4 (at cylinder TDC) to +4 (90 degrees ATDC).

I wish I'd thought of this!

[varium]

Originally Posted by duckdawg

kinda like your first wife...

Aaaaaahahahahahahahahahahahahahaha






No, seriously, that's not funny.









































She has a disorder and can't help it.





























Her hand can't stop stuffing food down that cave she calls a mouth.








































Oh, and that 454 is only half her weight. I give whole new meaning to pushing weight, son.

[GAMBLER]

Yamaha claimed 182 PS at 12,500 rpm with 115.5 Nm of torque at 10,000 rpm.... via Yamaha UK site.

weight?