sequential efi on 440?

[Scott Shotton]

Carl Summers wrote:
> 
> Mike Williams wrote:
> >
> > I'm building a chrysler 440 for in my 4x4 picup and would like to use
> > sequential efi. I sent mail to Electromotive and Felpro. Have'nt heard
> > from them yet. Right now I'm triing to decide on the cam. Called Comp
> > cams for advice, they said most mutiport efi makers don't recommend a
> > cam 220 degrees duration @0.050. Is this right and why?  P.S. Most of
> > the material in this group is over my head but I'm learning. Thanks to
> > you all...Mike
> 
> Mike,
>   It has been my experience that cams with too much overlap don't like
> to idle at 14.7 afr,,,If you have a way to adjust your afr(closed loop)
> at say 1000 rpm and down, it can be taken care of,,,other wise you can
> run as large a cam as you want,,,One other note about large cams is they
> tend to have very little vacuum at low rpm and right off of idle
> increase their efficiency dramatically causing major changes required in
> the map,,,and if EGR is a factor the EGR tables have to be changed
> accordingly(as large overlap EGR's itself under manifold vacuum) It can
> be a nightmare to tune. But the horsepower increase of a large cam is
> always nice......hope this helps....
> -Carl Summers



Idea:

if a vacuum switch that diverted a vacuum source to two different
locations under two different conditions:

1.  MAP could recieve manifold vac info off idle.
2.  the vacuum source to the MAP could be diverted to a vac. canister.  
    The vac canister could build vac during driving and hold vac with
    check valves.  This way 18" could be applied to the MAP at idle.

in theory...  eliminating the rich idle problem.

(maybe way out there, but I thought I'd share it anyway)

Scott