RE: pfi & 747's

[Carl Summers <InTech@writeme.com>]

Hi all,
    I played with an edelbrock tbi/tpi once and had to change the O2 gains
as well as a bunch of other things to make it work OK....Self certifying
Edelbrock didn't look very good to me at that time....I however lost all of
those .bins due to a format of the hard disk(I know...back ups) So anyway
keep that in mind at any point you want to change the physicality of the
injectors and not just the constant other things have to be changed....hth's
-Carl
p.s   Anyone wanting to throw some Edel .bins my way.....I would like to
look at them again.  To give you an idea of how bad the PI gains
were...hmmmm how do I describe without a wav file....2200 rpm in
neutral......vrrrrrp vrrrrrp vrrrrrrp vrrrrrp about every 1 1/2
seconds....clean out the tailpipe(thanks to the cat) and blms and
integrators steady......Only got crazy like that once EGR was active and all
hell broke loose....This was an electric egr 454 94 model....ttyl


-----Original Message-----
From: owner-gmecm@diy-efi.org [mailto:owner-gmecm@diy-efi.org]On Behalf
Of Mike Rolica
Sent: Thursday, August 24, 2000 6:12 AM
To: 'gmecm@diy-efi.org'
Subject: RE: pfi & 747's


	 wouldn't be too quick to dismiss the '747 for a port
	injected engine. Edelbrock sells a pfi conversion kit to
	convert '747 powered trucks over to port.

	In the tables they change the injector constant to 112, and
	the pump shot stuff to smaller values. The most interesting is
	that they leave the injector bias, min bpw, max bpw and the
	'switch to async' mode pulse widths the same.

	The key is to find out if they are using saturated or p&h
	injectors. Anybody know about this? Other thing in their
	favor is that these trucks are not revving too high. Although
	they add fuel fuel right up to the end of the ve table.

	I'd bet they are using p&h injetors. As the pfi p&h's are
	twice the impedence as the tbi p&h's, you could drive
	four from one driver, in a parallel/series configuration.

	BobR.

	p.s. still working on an iac writeup, I'm knee-deep in school
	work, bit more off than I could chew. . . or is that grabbing
	a hot iron by the end opposite the handle <g>

	(Three more Months!)


	I hear ya.. I start buck next week.. three moths of hell!!! :-)
	(least I can tune on 45 min drive to school)
	--



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