Holley 4barrel TBI, 700 cfm or 454 TB? Q's

[Mike Rolica]

drill your manifold for port injection..use tpi fuel rails or built your
own... then use a 600 holly base plate as the throttle body.... guy on the
list did it with a mopar.. had pics.. real slick setup..
course you would have to use a 730 :)

-----Original Message-----
From: olbap [mailto:olbap at mail.mia.bellsouth.net]
Sent: Friday, June 16, 2000 7:19 PM
To: gmecm at diy-efi.org
Subject: Holley 4barrel TBI, 700 cfm or 454 TB? Q's


Hey all,

My cars WOT is tuned really well with the stock throttle body now, managed
to do it in a day after I discovered the prom editing program had a glitch
in the main spark table (was always running like 26 degrees total timing
before.. nowonder it ran like caca). It runs pretty good, but the motor is
seriously choked, by 4300 rpm its done building power in first gear, and by
5800 rpm im seeing around 2.5" of vacuum at WOT. (the power band is almost
diesel motor-esque)

Obviously I need a bigger TB, I thought surely the 670 cfm would feed my
motor till I discovered at 1.5inHg it probably flows just under 500 cfm
which im not sure will be enough to feed the top end monster this motor was
built to be.

My other option is a holley analog (doesnt have an IAC motor)   4 barrel TBI
unit, with 65 lb injectors, brand new for 175 bux.  I like this one because
it surely will feed my motor since its measured at 1.5inhg (not 100% sure on
that but I think so) also because this should feed the 350 or 383 im
planning to build next eventually. I can also run it withoutany adapters,
andstill have hood clearance to experiment with spacers. The only problem is
wiring the injectors It seems. Ive heard that wiring them in series can
cause erratic performance of the second injector in line. 

I noticed a while back that my ecm seems to have four wires going to the
injectors.. two of which tie back in to the wire next to it. Its my
understanding that the ecm simply uses these wires to ground the injectors
and this is how it controls them. 

So I guess my questions are A) Can the 454 TBI unit really feed my motor? I
want this thing to just rip from 5000-6000 like I felt it do with a holley
600 cfm carb
B) If not, are the things ive heard about wiring theinjectors in series true
on the 4 barrel?  If so, how hard would it be to fashion a powersource
forthem, and can i just use those two extra spots on my ecm to control them?
(assuming my understanding of how the system functions is correct)
C) Will running sans IAC motor have any real bad effects other than just a
little sacrifice in idle 'driveablity'?


Any and all opinions (good or bad) welcome

Pablo

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