Intake Runner Length

Bruce Plecan nacelp at bright.net
Tue Feb 2 20:13:59 GMT 1999


-----Original Message-----
From: Van Setten, Tim (AZ75) <Tim.Van.Setten at CAS.honeywell.com>
To: diy_efi at efi332.eng.ohio-state.edu <diy_efi at efi332.eng.ohio-state.edu>
Date: Tuesday, February 02, 1999 1:27 PM
Subject: RE: Intake Runner Length


> Massive Brutal snippage
>
>Injector timing is done by converting the input pulses from the coil
(freq.)
>into a dc voltage.  Next step is using a dc-freq. converter (PLL) to set
the
>rep. rate for the inj. timing.  I found that when I run the inj. at approx.
>8% faster than what the engine is running, the bottom end and mid range is
>fantastic!  If it is set to 1:1, it stumbles or hesitates.  I can
>momentarily speed up the freq. of the inj., and/or increase the duty-cycle
>for an accel. pump action, but it's not the same.  An Accel pump seems to
>kill the off idle transition in a port inj. design.  I can also slow down
>the freq. of the inj. (to eng. freq.) to lean out the idle if the pulse
>width gets to narrow. (Remember we are using anywhere from 32 lb/hr to 60
>lb/hr, low impedance injectors).
>The TPS input goes thru different op-amps that the gain is controlled by
the
>engine freq, thus the different ranges, idle, mid, and top or wide open.
>Did I help at all, Bruce?

Yep, but Doc, and Grumpy's eyes have glazed over.  This Phased
Locked Loop Stuff is like shuttle trajectory calculations, for them.
OK, us........
Bruce

>Tim
>




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