RPM independence

[Howard Wilkinson]

Todd:
    Ford uses at least two sizes of oil pump drive rods.... perhaps
this is different.                          H.W.

P.S.  Thanks for the magazine article info.... I'll try to obtain it.

-----Original Message-----
From: Todd....!! <atc347 at c-com.net>
To: diy_efi at efi332.eng.ohio-state.edu
<diy_efi at efi332.eng.ohio-state.edu>
Date: Wednesday, May 12, 1999 5:18 PM
Subject: Re: RPM independence


>Oh man Ted,
>
>I got it from RANDALL'S, on Fuqua street right here in South Houston,
by
>Pearland....
>
>It's a very cool mag and talk about some power producing mules!!
>
>ALL the cars in it are FI'd some turbo'd some not, but ALL haul some
>MAJOR BOODY!
>
>Haven't finished the mag yet, but it's been great thus far...
>
>They only speak about GM efi as well as aftermarket but no other
brands
>of oem efi systems suchb as the EEC's from Fart..er Ford....
>
>BTW I DID get my 83 t-birds ignition to work with my good ol backup
>electronic distributor from my Dodge!
>
>Two wires and I was there, it's a spark producin foooo....
>
>Had a great and powerful spark too...
>
>however couldn't get the dern points distributor in the engine's
>distributor hole, the points distributor was too big for the hole!!
>Wierd, ey?  Haven't found an answer as to why yet, maybe I snagged
the
>wrong distributor, like one outof a 351 instead of a 302, I can't
tell
>the diff, they looked so similar!!
>
>If anyone has any insight to this, please let me know...
>
>Plans are to go back the the yard and trade the points for a newer
>electronic distributor out of a newer model Ford car...
>
>Any advice?
>
>LATER!
>
>Todd....!!
>
>Stowe, Ted-SEA wrote:
>>
>> where do you get GM High-Tech Performance ?
>>
>> > -----Original Message-----
>> > From: Todd....!! [SMTP:atc347 at c-com.net]
>> > Sent: Wednesday, May 12, 1999 9:53 AM
>> > To:   diy_efi at efi332.eng.ohio-state.edu
>> > Subject:      Re: RPM independence
>> >
>> > Howard the article is in the May 99 issue of GM High-Tech
Performance
>> >
>> > And the brand that uses Volumetric and other formulae instead of
look-up
>> > tables is known as Electromotive....  Probably heard of em?
HAHA!??
>> >
>> > Keep me informed of your progress in this matter!
>> >
>> > LATER!
>> >
>> > Todd....!!
>> >
>> > Howard Wilkinson wrote:
>> > >
>> > > Todd:
>> > >     I would be very interested in reading the article you
mentioned.
>> > > Please let me know if you find it.
>> > >     My basic thought here is to emulate the working of the
Bosch
>> > > mechanical CIS fuel injection system electronically which would
allow
>> > > it to be modulated by feedback, but still yield a system simple
enough
>> > > to be operated by a very low cost controller.  Injector timing
is
>> > > irrelevant, therefore injector firing rate is also irrelevant
within
>> > > the range above engine RPM.
>> > >     Perhaps mathematical formulae are not adequate to control
fuel
>> > > delivery.... maybe lookup tables are necessary.  The Bosch
mechanical
>> > > system used a shaped MAF to keep fuel flow which was
mechanically
>> > > controlled in line with the motion of the MAF actuator arm.
This put
>> > > the mathematical calculation into the profile of the MAF throat
which
>> > > was in effect a computer (a mechanical computer).  It took far
more
>> > > intelligence in my opinion to design this one part than to
program
>> > > look up tables which can be done by trial and error, or by a
simple
>> > > feedback system.  I believe I could sit here and flow chart out
and
>> > > write a program to generate the lookup tables based on
feedback, and
>> > > minimal programmer input.  I'm just looking at different
possible
>> > > approaches to the problem of managing fuel delivery via
computer.
>> > >                                         H.W.
>> > >
>> > > -----Original Message-----
>> > > From: Todd....!! <atc347 at c-com.net>
>> > > To: diy_efi at efi332.eng.ohio-state.edu
>> > > <diy_efi at efi332.eng.ohio-state.edu>
>> > > Date: Tuesday, May 11, 1999 1:15 PM
>> > > Subject: Re: RPM independence
>> > >
>> > > >Hello Howard,
>> > > >
>> > > >your theory is TOTALLY GREAT and acceptable, and a system has
alread
>> > > >ybeen created, produced, and marketed, and it's gone over wiht
a
>> > > pretty
>> > > >good fine tooth comb within on eof the laterChecvy Hi po mags
dealing
>> > > >with all of the diff types, makes, and brands of FI for just
about
>> > > any
>> > > >type engine!
>> > > >
>> > > >Will get the name of the mag, I know you already know about
the mag,
>> > > >just maybe not about the article(s) within this specific
issue?
>> > > >
>> > > >But the basic function of the type system I believe you are
referring
>> > > to
>> > > >is based upon the use of formulas instead of tables... I think
you
>> > > are
>> > > >right in line witht the way this REALLY advanced system is
designed
>> > > to
>> > > >function!
>> > > >
>> > > >Will post details later, (mag's at home)!
>> > > >
>> > > >LATER!
>> > > >
>> > > >Todd....!!
>> > > >
>> > > >Howard Wilkinson wrote:
>> > > >>
>> > > >> I have given more than a little thought to the possibility
of an
>> > > EFI
>> > > >> system that operated completely independently of engine RPM.
The
>> > > idea
>> > > >> being that as the injectors are batch fired anyway, the
timing is
>> > > >> irrelevant so long as the injectors fire at engine RPM or
more.
>> > > >>     Such a system could be almost entirely MAF based.  The
>> > > injectors
>> > > >> would begin at a very short pulse width, and simply increase
pulse
>> > > >> rate up to a set pulse rate where width would be increased
>> > > thereafter.
>> > > >> Such a system could be operated based on mathematical
formulae
>> > > rather
>> > > >> than on look up tables.  A simple equation based on ECT
could
>> > > modify
>> > > >> the result for cold operation, and a TPS modifier would give
>> > > >> accelerator pump effect.  Map should not be necessary as air
>> > > density
>> > > >> should directly effect MAF output.  An O2 loop would handle
minor
>> > > >> dicrepancies.
>> > > >>     A lot of the complexity of the common EFI systems comes
from
>> > > the
>> > > >> desire to fire the injectors once per revolution.  Because
of RPM
>> > > >> dependence, the MAP, MAF, & TPS outputs are meaningful only
in the
>> > > >> context of RPM.  Total fuel delivery per unit time is only
directly
>> > > >> related to MAF.... It is not closely related to RPM,
Throttle
>> > > >> Position, or Vacuum individually as it is to MAF.  The MAF
tells us
>> > > >> how much fuel we must deliver per unit time, but the system
must
>> > > then
>> > > >> work out the pulse rate based on RPM, and pulse width for
that rate
>> > > to
>> > > >> achieve the desired delivery per unit time.
>> > > >>     If we know that x amount of fuel is delivered at Y pulse
width
>> > > per
>> > > >> pulse, then it becomes a simple matter to determine how many
pulses
>> > > >> per unit time are required to deliver that amount of fuel.
At some
>> > > >> point pulse rate reaches a max practical limit, and at that
point
>> > > >> pulse rate can become constant, and pulse width may be
modified
>> > > above
>> > > >> that point to control fuel delivery.  The fewer factors you
are
>> > > >> changing the simple the program becomes.
>> > > >>     Perhaps this is a simple minded vew of the process, but
then
>> > > I'm a
>> > > >> simple minded sort of guy.... I am of the "KISS" school of
thought.
>> > > >>                                 H.W.
>> > > >
>> > > >
>> > > >
>> >
>
>
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