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its amazing for years we were using batch without any issues....

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Information about wall wetting/puddling:
http://www.megamanual.com/ms2/xtau.htm

I would think the goal would be to fire the injector at the open valve, but at high speed and long PW times it may overlap with a closed valve.

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Yea, that's what I talking about, the link might take a few rereads to digest.

This leads into another related topic, seems like any intake tract coatings would have a downside regarding the wall wetting/evaporation issue, either by causing worse puddling with a slick coating, or slow down evaporation with an insulating style coating.

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Information about wall wetting/puddling:
http://www.megamanual.com/ms2/xtau.htm

I would think the goal would be to fire the injector at the open valve, but at high speed and long PW times it may overlap with a closed valve.

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Yea, that's what I talking about, the link might take a few rereads to digest.

This leads into another related topic, seems like any intake tract coatings would have a downside regarding the wall wetting/evaporation issue, either by causing worse puddling with a slick coating, or slow down evaporation with an insulating style coating.

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Thats why we spray the fuel in at higher pressures..
it will atomize much quicker.. the fuel particles
are much smaller.. and the pattern of the spray makes
a big difference also.. most all of the injectors now
spray a cone shape with different amount of fuel in
different areas of the cone.. I had to measure the
amount of fuel in each section of the cone... vs
the straight spray of fuel.. this type of injector
would puddle and as said, was hard on emissions..
you dont just spray in a certain amount of fuel but
how its sprayed in

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Also thats why you have a few sensors to tell the
injector when and how much

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Yep, pulse width............lower r`s less fuel wider width higher r`s more fuel tighter width or so I heard.

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What do you think a carbureted engine is doing during the closed intake intermission ?How about mechanical fuel injection ? If your injector is at 90%, its time to buy bigger injectors.

You have a thingy in EFI that is called a "injector phase angle " it is where you tell the injector to fire in relationship to the valve opening .Just think of it as example of the law of diminishing returns . When you are idling around ,the EFI has a measured fuel delivery at precise times and all is happy , but when you are a 8000 RPM its pretty much just blasting fuel in at precise times .

The reality is not the slow-motion lazy fuel hanging around the valve mental image that you are imagining .

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What do you think a carbureted engine is doing during the closed intake intermission ?How about mechanical fuel injection ? If your injector is at 90%, its time to buy bigger injectors.

You have a thingy in EFI that is called a "injector phase angle " it is where you tell the injector to fire in relationship to the valve opening .Just think of it as example of the law of diminishing returns . When you are idling around ,the EFI has a measured fuel delivery at precise times and all is happy , but when you are a 8000 RPM its pretty much just blasting fuel in at precise times .

The reality is not the slow-motion lazy fuel hanging around the valve mental image that you are imagining .

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If you could see the 9500 rpm event in slow motion the injector isn't closed much. Also, you really don't even need a cam position sensor on a race car.

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Even at 85% duty cycle(WOT) you would swear its on
all the time. I know it isnt but the sound sure sounds
like it.. its just a buzz(I was testing this stuff
on a test stand built just to test injectors without
any engine in play) so I could flow the injectors at
different duty cycles and we tested at different voltages..
you would be really surprised at how they act at low volts

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Heck back in 1989 I was trained on the Dodge Monaco which was not like the old Monaco's as this used a foreign V-6 and it sprayed all injectots all the time everytime an injector fired they all fired. Mopar also did this before they went to ported and sequential injection. The 3.0 v-6 would fire half the injesctors all the time. Which 3 depended on which cyl was fireing. And before that they used throttle body injection as most were 2 barrels and would spray both injectors on every dist signal. Course didn't need a cam sensor on that setup. They finally went to sequential in the early to mid 90's. Mopar also used the 02 just for the fine tuning as the addaptive memory had a larger control over fuel mixture and then once in the right addaptive cell the 02 would fine tune it. Ron

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I use to flow the throttle body injector(note singular)
back in the beginning of Chrysler injection.. I
built the first flow stand at Chrysler years ago
for testing injectors... I've flowed a FEW injectors
over the years

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You mentioned different spray patterns, is there an injector that sprays at closer to a 90 degree angle,ie downstream, instead of the floor of the intake opposite of the injector?

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None that I have heard of
EDIT
also in the way a injector is designed it would be
real are to get one to fire at 90*.. if you look at
it, its got a long needle and seat per say.. the needle
is called the pintle which is pulled upward by the
electro magnet when fired and if the fuel touches
anything it would puddle so you cant just put a 90*
on the end of the injector