Re: Duty Cycle and VE ??

["Bruce Plecan" <nacelp@bright.net>]

> I'm very confused right now.  I have my VE's around 2000 rpm set to 99%,
but at 50+ kPa >it runs lean, really lean (at 1900-2100rpm I get 60-100mV
continually).  My injector >constant is set to 38lb/hr and i'm now running
65psi fuel pressure, so I should bump my constant up to correct.

What is your FP at extended WOT?.  Better yet, what is the return line
pressure at WOT.  What is the pressures when lean?.
I'd do alot of things to get that FP down, seems way outta line for what ya
got.  I would think that maybe ya missed something, and just continued down
the road too far, BTDT...

Something just ain't adding up, at 38 injectors, ya should be able to feed
like 640 HP, you clai 540, you should be way in excess.
What for injector duration (and rpm) do you have at idle?.

> I've looked through the archives for duty cycle math, but i'm still not
clear on it.

By example, at 6,000 rpm, you have 100 events per sec (6000/60), so you have
a total time between injector events of 10 millisec., at 3,000 rpm 20
milisec,
Once ya get the 10 millisec at 6,000 down it's pat, AND this is for your
batch fire at once per revolution.
   So if at 6,000 you have an injector on time of 8 millisec., that is 8
milliseconds of a total of 10 or 80% duty cycle.
   At a idle of 600 rpm you have a total time available of 100 milliseconds,
a pulse of 2 would be a 2% duty cycle.
   That help?.

  I need to
> figure out if i'm maxing out my injectors or if my VE could possibly be
over 99%?

If muffled highly unlikely,

> I know that full-throttle at 50psi FP/5000 rpm was around 10ms PW and
around 850-900mV.
>
> Could this be caused by an ignition timing problem?

Easily.
Grumpy

> Squash
> p.s. 730/aujp/468cid/NA/525ish HP/38lb injectors


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