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Re: Ford injectors (& Question) MORE
Funny you should mention valve springs.. They are presently kept at "coil
bind" rating of .510. Cam * 1.5 exhaust = .510 exactly (502 int w/1.5's,
510 exh w/ 1.6's) Intake duration is really too small too I think...
(GM ZZ3) 208/221 dur @ .05, 474/510 lift w/1.5, 112 sep
AFR is stable (for now) but yes, for me to 'move on' its time for the 24's
PS: Wanted: used aftermarket TPI base ;-)
----- Original Message -----
From: Carl Summers <InTech@writeme.com>
To: <gmecm@diy-efi.org>
Sent: Monday, August 21, 2000 11:27 PM
Subject: RE: Ford injectors (& Question) MORE
> Hi Dave,
> Sounds like you have the right idea....When the injector(saturated
> circuit) gets above 85% commanded duty cycle you can start seeing the
> unstable AFR's...In real world the injector seems to become unstable
around
> 81-82% real duty cycle.....so I guess what I am trying to say is even if
you
> get to the 85-90% commanded duty cycle...I still woudn't worry about the
> life of the injector as long as AFR is stable...kinda like valve
> springs...don't keep em at valve float or could have a disaster...hth's
> -Carl Summers
>
>
> -----Original Message-----
> From: owner-gmecm@diy-efi.org [mailto:owner-gmecm@diy-efi.org]On Behalf
> Of Dave Zug
> Sent: Monday, August 21, 2000 10:39 PM
> To: gmecm@diy-efi.org
> Subject: Re: Ford injectors (& Question) MORE
>
>
> It has been said and I think I mostly understand the explanations...
>
> Thus far I am still in total control of the AFR. safe at 0.93 then power
> chip set down to 0.87 - 0.89.
>
> using the o2 method, if the AFR is controllable that is, works but if
you're
> at 97% DC thats no good even though the o2's and the EGT says its fine....
> least thats what I gather from reading, and like I've said before, I'm
> reading more than I am 'doing' so no real experience going in.. so the
> feedback is definetly appreciated!
>
> Thanks carl.
>
> PS - I'm still in search of that bargain blower ;-)
>
> ----- Original Message -----
> From: Carl Summers <InTech@writeme.com>
> To: <gmecm@diy-efi.org>
> Sent: Monday, August 21, 2000 6:48 PM
> Subject: RE: Ford injectors (& Question) MORE
>
>
> > Hi,
> > I can't get into the right/wrong stuff but can tell you
programmable
> pw
> > and actual pw are different...I think this has been said before....If ya
> > want to know whether you're getting maxed out....it's when the AFR
starts
> to
> > not repeat...ttyl
> > -Carl Summers
> >
> > Click on this link below to see the easiest way to handle internet
> > transactions.
> >
> > https://secure.paypal.com/refer/pal=drsagan%40pacbell.net
> >
> > -----Original Message-----
> > From: owner-gmecm@diy-efi.org [mailto:owner-gmecm@diy-efi.org]On Behalf
> > Of Dave Zug
> > Sent: Monday, August 21, 2000 9:56 PM
> > To: gmecm@diy-efi.org
> > Subject: Re: Ford injectors (& Question) MORE
> >
> >
> > Sorry to keep this going, but I have more:
> >
> > I analized the pulse widths that I am getting (383 CI TPI w/ stock 22#
> > injectors, 360 HP est) verses the max PW for a range of RPM's (3600 -
> 5500
> > : My "drag zone") and although I am seeing 13 ms pulses, they occur in
an
> > rpm range that allow a maximum of 16 msec thus my duty cycle times are
> FINE!
> >
> > RPM/ MAX Allowable PW/ Measured PW /Measured Duty Cycle
> >
> > 3600 16.7 12.9 77.4
> > 3750 16.0 12.3 76.875
> > 3900 15.4 12.4 80.6
> > 4050 14.8 12 81
> > 4200 14.3 11.6 81.2
> > 4350 13.8 11.2 81.2
> > 4500 13.3 11 82.5
> > 4650 12.9 10.8 83.7
> > 4800 12.5 10.5 84
> > 4950 12.1 10 82.5
> > 5100 11.8 9.3 79.05
> > 5250 11.4 9.2 80.5
> >
> >
> > Conclusion: My stock 22# TPI injectors are correctly sized for my
stroker
> /
> > large tube / header / 13.1 E.T. setup, even though I have PW's that are
> over
> > 10 ms.
> >
> > Right or Wrong???
> > TIA (again)
> >
> >
> >
> > ----- Original Message -----
> > From: Dave Zug <dzug@delanet.com>
> > To: <gmecm@diy-efi.org>
> > Sent: Saturday, August 19, 2000 2:19 AM
> > Subject: Re: Ford injectors (& Question)
> >
> >
> > > Thanks Roger.. I see my mistake. Much thanks.
> > >
> > > ----- Original Message -----
> > > From: Roger Heflin <rah@horizon.hit.net>
> > > To: <gmecm@diy-efi.org>
> > > Sent: Friday, August 18, 2000 3:50 PM
> > > Subject: Re: Ford injectors (& Question)
> > >
> > >
> > > >
> > > >
> > > > On Fri, 18 Aug 2000, Dave Zug. wrote:
> > > >
> > > > >
> > > > > So if I have this right, Let me write this in other terms...
> > > > >
> > > > > Lets say for example a car cruising is doing 5 ms pulses at a
> constant
> > > 6000
> > > > > rpm (for math's sake).
> > > > >
> > > > > Its pulsing like this:
> > > > >
> > > > > each bit is 0.5 ms: (2 crank revs = 1 cam rev =20 bits). 20 ms
time
> is
> > > > > represented (4 engine "strokes").
> > > > >
> > > > > 1111100000 1111100000 1111100000 1111100000 Left
> > > > > 0000011111 0000011111 0000011111 0000011111 Right
> > > > > <----------10 ms--------> <---------10 ms--------->
> > > > >
> > > > > Alternating left and right for HALF the PW time each 10 ms to
> complete
> > > the
> > > > > full PW time within one CAM rev.
> > > > >
> > > > > Then we go to WOT and for math's sake lets say we gain no RPM's or
> > > fueling
> > > > > requirements.
> > > > >
> > > > > Its pulsing like this:
> > > > >
> > > > > each bit is 0.5 ms:
> > > > >
> > > > > 1111100000 1111100000 1111100000 1111100000 Left
> > > > > 1111100000 1111100000 1111100000 1111100000 Right
> > > > > <----------10 ms--------> <---------10 ms--------->
> > > > >
> > > > > Now to the (almost) REAL world.. Heres what WOT looks like
(constant
> 9
> > > ms
> > > > > requirement) :
> > > > >
> > > > > each bit is 0.5 ms:
> > > > >
> > > > > 1111111110 1111111110 1111111110 1111111110 Left
> > > > > 1111111110 1111111110 1111111110 1111111110 Right
> > > > > <----------10 ms--------> <---------10 ms--------->
> > > > >
> > > > > The above example has the injectors on IN UNISON for a total of
(0.5
> > ms
> > > *
> > > > > 18) or 9 ms over each 10 ms (1/2 valvetrain cycle) period. the
> listed
> > PW
> > > > > then repeats itself for the next 10 ms with no recalculation
taking
> > > place
> > > > > (??) to complete the valvetrain cycle.
> > > > >
> > > > >
> > > > > Do I have it right?
> > > >
> > > > Close, I believe they actually pulse the given pulsewidth at once,
so
> > > > when the computer says 9ms it actually opens it for 9ms, and then
> > > > closes for 1ms, not (4.5ms, close .5, 4.5, close .5) On the
> > > > sequential cars it would list 9ms as 18 ms, and keep it open for I
> > > > believe the entire time or almost the entire cam rotation. I
don't
> > > > know if they alternate banks, I would need to look at the code to
> > > > figure out that and how exactly it compares to the actual cylinder
> > > > timing. My guess is that it may not really even match up
consistantly
> > > > with the cylinder timing, just close enough, I suspect also since
the
> > > > injectors have difficulties with being closed for short periods of
> > > > time that that may be the reason to not even try to time single
> > > > cylinder events, since this would required bigger injectors to avoid
> > > > getting the close time too low.
> > > >
> > > > Roger
> > > >
> > >
> >
> > -
>
> ----- End of forwarded message from owner-gmecm@diy-efi.org -----
> --------------------------------------------------------------------------
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