Max rpm our 7.3's can effectively turn

85_305

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What dave is saying is that as the rpms of the motor go up your duration/window of the crank degrees to efficiently inject fuel gets shorter in actual time the duration never changes just the rpms.
So saying you are wanting to inject 2.1ms at 2500 rpm.. Now take 2.1ms to 6000 rpm there is not 2.1ms of time there to possibly inject fuel. The tuning causes this if the tuner doesn't pull back his pw as the time window gets shorter.

And to have two injection events going at the same time will self destruct the motor. There is alot more to the tuning side of it how they overcome the injection window getting narrower and narrower as rpms increase

The IDM only goes as fast as the PCM commands it to... There is no magical secret to horsepower lying in the IDM

:doh: that totally makes sense about somebody trying to inject fuel within 2.1ms when there physically isn't 2.1ms available at that rpm... that just made it click in my brain what everybody is referring to by saying that.

Maybe a stupid question, but is it possible to inject the fuel too fast? I had always thought the faster the better, but is it possible to inject fuel too quickly at lower/mid rpms?
 

silverpsd_06

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Its possible to inject it to early but as far as too fast i don't really see that being an issue the faster you can get it injected in your window the better off you are. Bringing fuel in too early or in mass quantities will break chit for sure.
 

Magnum PD

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I talked to a guy that had a cummins, he told me there is an injection of fuel (I'm gussing) at the end of the exhaust stroke. Sound crazy?
 

Gearhead

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135 before top dead center is the maximium electrical advance. Remember, just because you tell it to inject RIGHT NOW, it doesn't mean that it is going to do it in any hurried fashion. When the oil and fuel are at freezing temperatures, you'd be suprised how much electrical advance is needed to get it to fire remotely close to TDC.
 

Charles

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135 before top dead center is the maximium electrical advance. Remember, just because you tell it to inject RIGHT NOW, it doesn't mean that it is going to do it in any hurried fashion. When the oil and fuel are at freezing temperatures, you'd be suprised how much electrical advance is needed to get it to fire remotely close to TDC.


Sounds like another in a long list of problems that a mech pump cares not one *** about...

Screw Heui...
 

Charles

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It's true, I am angry. Angry I wasted so much time trying to get oil from a waterspout. Most I ever got was muddy water.
 

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