Nother thought

[Dave Zug]

Dart pro-1 Alum. 45# FP,  have to shift at 5200-5300 or so. power dies above
that. Stock lower intake is a very effective restrictor mechanism..  man the
torque though!  I even have 1.6's on the exhaust valves.  the CR is 9.8 : 1.
Very comfortable in daily driving. the only lightweight component is the
fibreglass hood.  speaker box in the trunk helps with 60' but trap speed is
only 103. This is on a street chip and 89 octane... the way I take it to the
track all the time.  Working on implementing a very low HP (#14 jet, dry)
NOS kicker in conjunction with a little ECM fueling to get those last 2
tenths. (12.99 target).  edelbrock lower intake is slated for winter
project, and DSL.

----- Original Message -----
From: <timsiford at hushmail.com>
To: <gmecm at diy-efi.org>
Sent: Thursday, October 05, 2000 3:00 PM
Subject: Re: Nother thought


>
> >I think theres enough info here for my concerns to evaporate.
>
> You were concerned about lil 'ol me?  j/k  Thanks for lookin' out.  I
CANNOT
> believe you are getting away with 22lb injectors on a 383 with a ZZ4 cam.
>  What heads are you running?  At what RPM are you shifting?
>
> Tim
>
> >
> >----- Original Message -----
> >From: <timsiford at hushmail.com>
> >To: <gmecm at diy-efi.org>
> >Sent: Thursday, October 05, 2000 11:02 AM
> >Subject: Re: Nother thought
> >
> >
> >> Dave,
> >>
> >> Understood.  I'm in class right now but I'll post the PWs that gave
> >me the
> >> 100% DC later tonight.  I wrote a convenient VB program that I use
> >to
> >calculate
> >> all sorts of Automotive data.  The DC is based on batch fire cars
> >where
> >> 100% DC was equivalent to an injector Pulse Width of 10.0ms at
6000RPMs.
> >>  I'll post the full formula later.  NOTE:  I didn't consider opening
> >and
> >> closing time.  Thus, the DCs could be even higher.  I went over and
> >over
> >> and over swapping out my injectors.  Everyone in MAFB said that I
> >shouldn't
> >> need to go higher than 24lb injectors.  Diacom also reported AOK O2
> >voltages
> >> at WOT throughout the entire WOT run (0rpms->6500rpms).  I replaced
> >my
> >injectors
> >> SOLELY because of the DCs I was seeing.  Many people told me not to
> >replace
> >> my injectors ... that the 22lb injectors would be enough.  Diacom
> >supported
> >> that.  But, the DCs did not (and I was running 52psi at the rail).
> > I
> >upgraded
> >> to 24lb SVO injectors based on everyone's recommendations.  Well,
> >with the
> >> 24's I was seeing almost 90% DCs at 6500rpms.  Those injectors were
> >on my
> >> car for only an hour before I ordered a set of 30's.  The 30's have
> >acceptable
> >> DCs ... in the order of 77% at 6500rpms ... and, the car idles great.
> > I
> >> have the injector constant set to 33lb/hr in the PROM and I am running
> >45psi
> >> at the rail.
> >>
> >> I do remember that at 4500rpms my injector pulse width stayed pretty
> >static
> >> until up to 6500rpms.  The fact that the RPMs were increasing and
> >the IPW
> >> remained the same caused the DC to rise substantially.
> >>
> >> My butt-o-meter is very inaccurate.  You're talking with someone who
> >couldn't
> >> tell too much of a difference after swapping heads/cam.  But, with
> >the new
> >> SVO injectors (30lb) I noticed a difference in the upper RPMs.  If
> >I get
> >> to the track soon I might be able to prove it :-)
> >>
> >> Tim
> >>
> >> At Thu, 5 Oct 2000 10:00:52 -0400, "Dave Zug." <dzug at delanet.com>
> >wrote:
> >>
> >> >
> >> >To clarify, What Pulse width (in Ms) are you calling 100% DC  at
> >4500
> >> >RPM?
> >> >
> >> >Were your PW's constantly INCREASING as RPM went up?
> >> >
> >> >My 383 CI (360hp thereabouts, almost same cam as yours- less flow
> >above
> >> >5500
> >> >though, stock lower intake) uses stock 22# and stock FP almost, hits
> >> >85%
> >> >static for a BRIEF moment after the shifts. o2's still on the rich
> >side
> >> >according to GM sensor (093) , and plug condition backs it up.
> >> >
> >> >This is not meant as evidence contrary to your observations - just
> >more
> >> >info
> >> >to add to the collection.,.. mine and yours.
> >> >
> >> >----- Original Message -----
> >> >From: <timsiford at hushmail.com>
> >> >To: <gmecm at diy-efi.org>
> >> >Sent: Thursday, October 05, 2000 9:49 AM
> >> >Subject: Re: Nother thought
> >> >
> >> >
> >> >> I was running the stock 22lb injectors on my IROC (218cam, AFR
> >heads,
> >> >MiniRam)
> >> >> for about 3000 miles before swapping to 30lb injectors.  At WOT
> >I
> >> >would
> >> >> reach 100% DC by 4500rpms.  I would continue to shift at 6500.
> > This
> >> >is
> >> >>  great example of how the stock O2 cannot be used for tuning.
> >The
> >> >O2
> >> >volts
> >> >> were approx 830mV and greater throughout the entire RPM range even
> >> >though
> >> >> I was hitting 100% DC.  After switching to 30's I noticed
significant
> >> >improvement.
> >> >>  The stock 22lb injectors never falterered and still function great.
> >> >>
> >> >> Tim
> >> >>
> >> >> At Wed, 4 Oct 2000 23:22:33 -0400, "Bruce Plecan"
<nacelp at bright.net>
> >> >wrote:
> >> >>
> >> >> >
> >> >> >Anybody have any info., about the extended effects of running
> >really
> >> >> >high
> >> >> >DCs on injector drivers?.
> >> >> >Just thinking, out loud.
> >> >> >Just with all the hours of running stuff here, I can't find any
> >real
> >> >> >reason
> >> >> >for for the 85% DC, as applied to a street car.
> >> >> >Just maybe do to worry about a worse case thermal situation, and
> >> >portecting
> >> >> >the devices?.
> >> >> >Or maybe just a ol wifes tale....
> >> >> >Bruce
> >> >> >
> >> >> >
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