7747 spark control questions.

[Bruce Plecan]

> I would get a bog when trying to pull out quick. Normal (?)
> driving would be fine. It's a Performer RPM manifold with
> no heat crossover, and a valley baffle. Runs cold.

And you'll never get 8 plugs to look right.  Blocking the heat to a dual
plane is no answer.  You'd be alot further ahead to go with a low rpm single
plane.  Wieand makes 2 for the SBC, and if you want nice top end with a TBI
the 7525 is really nice IMB  (In My Book, hahaha, I just coined a nuther new
term).
   An unheated dually takes a bunch more pump shot.  You can get them to run
OK steady state, and in slow transistions, but the crispness needed for like
spirited driving will never be there.
   I bet I've got close to a 1,000 hours in trying to get cold dually to run
their best.  It was frustrating to see what just bolting in a cheap single
plane did.   I gave a tad off idle away, but picked up everywhere.
Bruce


 I knew it
> neeeded a bit more pump shot, but did not want it to affect
> the afr too much. I was still tuning the VE tables at the time.
>
> I had no idea that it would want so much PS. Probably could
> add more, O2 still dips a little on a quick throttle opening.
>
> BobR.
>
> >The early TBI 454 uses that biig iron carby intake, plus a heated
> >spacer/adapter, plus the bigger throttle bores, and the whole darn
> >thing runs hot enough to fry eggs.  Even the carb'ed stuff requires a
> >little more attention to throttle opening speeds and fueling on those
> >engines.
> >
> >Were you experiencing any other symptoms?  Just poor response?
> >Shannen
> >
> >rr wrote:
> >>
> >> Digression alert:
> >>
> >> Ever see the pump-shot values in that bin? They are seven times the
duration
>
> >> of a 5.7l bin! (ARHT) To get a decent throttle response on my 327 TBI,
I
> split
> >> the difference between the 5.7l bin and the ANTZ bin. I had originally
added
>
> >> 20% to the 5.7l bin, and it had no effect. I then added another 20%, no
> >> effect. Finally did the above change. Worked!
> >>
> >> BobR.
> >>
>
> >
> >
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