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at 2:44 it shows a set of injectors above the throttle bodies inside the air box am wondering whats the deal? pretty sure its not nitrous. any thought?
 

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not really an answear, so am going to guess its for more fuel at higher rpm's

In my defense, it wasn't much of a question ;-)
That would be my assumption as there's little to be gained by spraying additional fuel in at low RPM and/or less than full throttle.
To do this though would require a fuel controller that can operate the injectors seperately. Is he using the 1000RR ECU as well?
The 954 ECU would fire both injectors all the time as far as I can see, not really a problem, just not very effective.
 

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Discussion Starter #9 (Edited)
In my defense, it wasn't much of a question ;-)
That would be my assumption as there's little to be gained by spraying additional fuel in at low RPM and/or less than full throttle.
To do this though would require a fuel controller that can operate the injectors seperately. Is he using the 1000RR ECU as well?
The 954 ECU would fire both injectors all the time as far as I can see, not really a problem, just not very effective.
i see thank u:thumb:

i thought he might be using a old school power comander with the little nobs inside you turn with a screw driver to adjust the fuel. setin all the dials on it the same rpm and havin secondiars come in at that rpm because there all set the same, just thinkin out loud i could be wrong. i had a maunel power comander on my 954 for awhile when spraying it. it worked well but my bike was always running rich when not spraying it. needless to say, it came off pretty quick
 

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I thought about that but did not think they were due to like you said they should be only when full throttle. But could still be and just not set up right. :idunno::huh:

I didn't look at the video but to get the secondaries to function as they're designed to he would have to use a different ECU, or some high-tech fuel management system.
I'm sure they would work fine if both are firing full-time as you would alter the mapping to suit that. But I doubt there'd be any advantage to doing it this way.
 

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reasoning behind this?
It's there primarily to give the fuel more time to fully evaporate at high rpm before it goes past the intake valve(s). Even with large injection bodies, the air's truly honking down the hole when you're deep into the good part of the powerband, and the last thing you want is any liquid fuel being vaporized after the combustion event begins. :down:

An injector located in the port of the head is so close that at high revs there may not be enough time for the fuel to vaporize properly. Not all engines have this issue, but if you find it, you need to either change to a fuel that vaporizes easier, heat the air and/or the fuel, or increase the contact time.

It takes time to vaporize fuel, and in this case more distance = more time. Not a lot more, but enough. :thumb:

Another potential benefit is that you can have more precision at low revs by only using the first injector: using only one means that the low fuel flows required at low power settings are easier to control precisely.

Bringing the other one upstairs on line smoothly is just a different problem for the injection mapping to deal with. :nod
 
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