2010 pipes


44 replies to this topic
  • Scrubba

Posted March 10, 2010 - 01:57 PM

#41

Not true. First, the question of what the injector can deal with is entirely up to the programmed fuel curve and the physical delivery capabilities of the injector itself. Secondly, in a low speed, high throttle opening situation, there is both very low manifold vacuum and relatively low air velocity across the throttle body. In a carburetor, this had to be dealt with through the use of enrichment devices such as power valves (not like those on two-stroke exhausts) and accelerator pumps. These have to be manually calibrated and cannot respond to changing conditions in the venturi very well. An EFI unit has no such natural limitation, and can deliver fuel in the correct amount for any situation it is programmed to deal with.

Higher manifold vacuum and air flow comes only with higher speeds.

Very weird thing to say, that the throttle will be less open as speed increases? That's you, not the machine. Let me assure you that racing across the dry lake at Superstition, or the front straight at a GP race, mine doesn't behave that way.

As far as forceful induction, it will never go fast enough to do that if what you mean is that it would ever force enough air into the air box to increase manifold pressure (boost). The increase in air pressure at the inlets related to speed will, however have an affect on the pressure differential between the manifold and the outside air, and will cause air to flow more freely into the filter.
Cut out slots on the sides, on the other hand, are positioned in a way that will more probably reduce atmospheric pressure over them as speed increases.

But as I said, you can believe anything you like.


ahhh.... but you yourself have stated that the inlet cross section is greater than then the latter path of the airway. if therefore the latter path of the airway chokes down, turbulence and friction loss will occur, therby causing restriction, the same principle as restricting the exhaust.

In a finely tned system, all things have been calibrated for the benefit.

all this is a moot point, as the injectors have been eletronically programmed to
dispense X amount of fuel with the supplied amount of air. more air will not benefit anything, as the ef. will only compensate.

therfore i conclude:

the injectors and motor in the works units, have been set up to demand a greater amount of air than the stock setup, hence the cut outs.

Okay, this is too much for me. All this cerebral stimulus should be saved for things more essential to my existence, like how to improve the intake of money.

but thanks for the bench racin.

  • grayracer513

Posted March 10, 2010 - 02:39 PM

#42

ahhh.... but you yourself have stated that the inlet cross section is greater than then the latter path of the airway. if therefore the latter path of the airway chokes down, turbulence and friction loss will occur, therby causing restriction, the same principle as restricting the exhaust.

The combined inlet cross section is larger than the smallest point of the tract, but how you arrived at the whole turbulence crock is a mystery unsupported by a science I'm familiar with. If you would examine the intake system for a second, and think about the principals involved, you might understand it somewhat better.

First, it is fundamentally true that to move air, a pressure differential is required, and in the case of the engine, this is accomplished by the piston evacuating the cylinder on the intake stroke. The higher pressure air of the outside atmosphere then pushes air into the low pressure created by the piston. Second, in moving air through any tract in which the cross section changes, the speed will increase as the cross section decreases, and vice-versa.

In any recent YZF model, including but not limited to the 2010, the air path into the part of the air box where the filter is mounted is overall much smaller than the cross sectional area of the air filter flange, and smaller still than the area immediately around the filter. Past the filter, there is another large open space into which the intake bell is extended. This is all quite deliberate, and results in two desirable things;

  • The incoming air slows as it enters the large area in the immediate vicinity of the filter. This allows heavier solids to simply fall out of the air stream, and the lower velocity of air flowing across the filter increases the likelihood of dust being removed from the moving air by reducing the kinetic inertia of the solids. The turbulence created here is in no way restrictive, and actually works to the advantage of improved filtration.
  • The intake bell opens into an area of relatively still air below the filter, which the intake tract "sees" as the outside air. The engine essentially knows nothing about the filter or air box, and the intake can be tuned as if it were a stack terminating in open air. This is the same principal applied in "tunnel ram" manifolds, and the port fuel injection systems in the automotive world. As long as the restrictions imposed by the air filter and the rest of the outer intake system can be kept to the level at which the air pressure below the filter is at or near atmospheric, there is no advantage to be gained by increasing air path into the outer intake.


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  • delmas

Posted March 10, 2010 - 05:52 PM

#43

The combined inlet cross section is larger than the smallest point of the tract, but how you arrived at the whole turbulence crock is a mystery unsupported by a science I'm familiar with. If you would examine the intake system for a second, and think about the principals involved, you might understand it somewhat better.

First, it is fundamentally true that to move air, a pressure differential is required, and in the case of the engine, this is accomplished by the piston evacuating the cylinder on the intake stroke. The higher pressure air of the outside atmosphere then pushes air into the low pressure created by the piston. Second, in moving air through any tract in which the cross section changes, the speed will increase as the cross section decreases, and vice-versa.

In any recent YZF model, including but not limited to the 2010, the air path into the part of the air box where the filter is mounted is overall much smaller than the cross sectional area of the air filter flange, and smaller still than the area immediately around the filter. Past the filter, there is another large open space into which the intake bell is extended. This is all quite deliberate, and results in two desirable things;

  • The incoming air slows as it enters the large area in the immediate vicinity of the filter. This allows heavier solids to simply fall out of the air stream, and the lower velocity of air flowing across the filter increases the likelihood of dust being removed from the moving air by reducing the kinetic inertia of the solids. The turbulence created here is in no way restrictive, and actually works to the advantage of improved filtration.
  • The intake bell opens into an area of relatively still air below the filter, which the intake tract "sees" as the outside air. The engine essentially knows nothing about the filter or air box, and the intake can be tuned as if it were a stack terminating in open air. This is the same principal applied in "tunnel ram" manifolds, and the port fuel injection systems in the automotive world. As long as the restrictions imposed by the air filter and the rest of the outer intake system can be kept to the level at which the air pressure below the filter is at or near atmospheric, there is no advantage to be gained by increasing air path into the outer intake.


How did this thread morph into this scientific discussion when all I did was talk about how I was to quick to complain about the fitment of my pipe.
That I was wrong about.
I promise Carmichael would kick ass on a 2 stroke.

  • Scrubba

Posted March 10, 2010 - 10:52 PM

#44

The combined inlet cross section is larger than the smallest point of the tract, but how you arrived at the whole turbulence crock is a mystery unsupported by a science I'm familiar with. If you would examine the intake system for a second, and think about the principals involved, you might understand it somewhat better.

First, it is fundamentally true that to move air, a pressure differential is required, and in the case of the engine, this is accomplished by the piston evacuating the cylinder on the intake stroke. The higher pressure air of the outside atmosphere then pushes air into the low pressure created by the piston. Second, in moving air through any tract in which the cross section changes, the speed will increase as the cross section decreases, and vice-versa.

In any recent YZF model, including but not limited to the 2010, the air path into the part of the air box where the filter is mounted is overall much smaller than the cross sectional area of the air filter flange, and smaller still than the area immediately around the filter. Past the filter, there is another large open space into which the intake bell is extended. This is all quite deliberate, and results in two desirable things;

  • The incoming air slows as it enters the large area in the immediate vicinity of the filter. This allows heavier solids to simply fall out of the air stream, and the lower velocity of air flowing across the filter increases the likelihood of dust being removed from the moving air by reducing the kinetic inertia of the solids. The turbulence created here is in no way restrictive, and actually works to the advantage of improved filtration.
  • The intake bell opens into an area of relatively still air below the filter, which the intake tract "sees" as the outside air. The engine essentially knows nothing about the filter or air box, and the intake can be tuned as if it were a stack terminating in open air. This is the same principal applied in "tunnel ram" manifolds, and the port fuel injection systems in the automotive world. As long as the restrictions imposed by the air filter and the rest of the outer intake system can be kept to the level at which the air pressure below the filter is at or near atmospheric, there is no advantage to be gained by increasing air path into the outer intake.


exactly my point, therefore, if the works bikes need additional cutouts, it must be required by the motor.

as for the velocity of increase through a decreasing diameter, it really doesnt matter how fast the air is traveling, if the volume is minimal.

btw the smaller the cross section, the greater the friction loss.

who cares if you can suck milk through a tiny straw faster than a starved jackrabbit, if youre only gonna get an ounce in one hour? better get a bigger straw right?

as for this turning into a big discussion, i appologize, but the success of my Mensa candidacy obligates me to participate in any discussion of intellectual impertinence.:banana:

  • grayracer513

Posted March 11, 2010 - 10:19 AM

#45

...if the works bikes need additional cutouts, it must be required by the motor.

Now that's logical. It assumes they actually need it, which is not in evidence. Reminds me of another story:
Posted Image

who cares if you can suck milk through a tiny straw faster than a starved jackrabbit, if youre only gonna get an ounce in one hour? better get a bigger straw right?

Flash: Blind Squirrel finds a nut. This is actually makes a fair analogy of the situation with the air box. Let's say the straw you're drinking with is pretty ordinary, say 1/4", and the glass is shaped like an hour glass, with a waist the size of a dime. Is the dime sized waist going to restrict the milk from flowing from top to bottom, interfering with drinking through the straw in any practical way? No. Will increasing the waist size have any noticeable effect on the operation of the straw? No.

as for this turning into a big discussion, i appologize, but the success of my Mensa candidacy obligates me to participate in any discussion of intellectual impertinence.:banana:

That has not been the subject matter here. But, just to be realistic, the likelihood of you being a Mensa candidate is on a par with my chances of being the next American Idol (or of my being a Mensa candidate, to be pragmatic). Rudimentary spelling skills are generally a prerequisite as is a better command of vocabulary than is demonstrated by such awkward and obviously tendentious contrivances as "supplying quantitative volumetric parameters". Nevertheless, I've been waiting for you to go here with this. Now everyone can pretty much see what you're up to without me pointing it out.

Enjoy the rest of your day. Really.





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