[Gmecm] Re: Running V8 with $A1 DIS code

[William Lucke]

Ok, that's basically what I was thinking... The value was set to 60 as the 
code came from the V6. It maxes at 90, which would be appropriate for 
operating a 4 cylinder and accepts no negatives. I would have guessed 45 as 
well, but it does not run well at 45... I guess that's what tuning is for.

have done:
injector constant
BPC/EGR table entries (injector flow rate vs. unitary displacement)
cylinder select
Will shortly have spark reference angle set to 45

Is there anything we've missed for converting V6 DIS code to V8 DIS code?

I need to review my notes... I remember something about the 4x reference 
not being 50% DC, but maybe I'm thinking of the actual ignition signal, not 
the reference.


Will



>Date: Thu, 14 Apr 2005 20:37:55 -0600
>From: "WopOnTour" <wopontour at hotmail.com>
>Subject: Re: [Gmecm] Running V8 with $A1 DIS code
>
>Actually 6cyl DIS fires a coil every 120 degrees, not 60
>But I agree with the 45.
>IIRC reference angle is the #of degrees between the IGN REF voltage state
>switches. Every 60 degrees on the V6 (triggering on every trailing edge or
>120 degrees) and on the 8 cyl that would be 45 degrees (triggering every 90
>degrees)
>HTH
>WOT
>
>----- Original Message -----
>From: "David Haggard" <david at newcovenant.com>
>To: <gmecm at diy-efi.org>
>Sent: Thursday, April 14, 2005 8:09 PM
>Subject: RE: [Gmecm] Running V8 with $A1 DIS code
>
>
>I would GUESS that the correct setting would be 45.
>
>An even-fire V6 with DIS is firing a coil at every 60 degrees of crankshaft
>rotation. So my guess is based on this. 360 degrees of rotation divided by 8
>cylinders is 45.
>
>Just a guess, mind you, but it makes sense to me.
>
>David Haggard
>    '88 WS6 Formula Firebird "SR-71 Black 'Bird"
>
>
>
> > -----Original Message-----
> > From: gmecm-bounces at diy-efi.org
> > [mailto:gmecm-bounces at diy-efi.org] On Behalf Of William Lucke
> > Sent: Thursday, April 14, 2005 7:42 PM
> > To: gmecm at diy-efi.org
> > Subject: [Gmecm] Running V8 with $A1 DIS code
> >
> > Ok, the mission: run an OBD-II Northstar with 7730 using $A1
> > DIS V6 code as the starting point.
> > Cylinder select has been changed to 8
> > Injector constant set appropriately
> > BPC/EGR table values set with correct ratio of unitary
> > displacement to injector size
> >
> > What is the "spark reference angle"? It was set to 60 for the
> > V6, but no value of it makes the N* idle even passably...
> >
> > I wouldn't think the V6 code would be sooo far off from what
> > the Northstar wants at idle that it just wouldn't run, even
> > when the appropriate parameters are set for an 8 cylinder...
> >
> > Tried different values for "spark reference angle" and seen
> > timing change, but can't find one that's right. What does
> > spark reference angle represent and how is it computed?
> >
> >
> >
> > Will



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