'749 questions

[rr]

I'm not too sure if I'm following this thread. So if this isn't what is being
asked. . .

The '749 w/a 2bar map scales the 2bar map reading into another 1 bar
map value. Then the code has access to both a 2 bar & a 1 bar value.
The conversion is: 1MapAdc = ((2MapAdc * 135) - 400) / 64

The code uses the 1bar map for stuff like baro & vac conversions.

When the MAP BPW term is calculated the code checks the option
bit to see if it is running a 2bar or 1bar MAP. Then one of two routines
are used. The 2bar MAP BPW term is calculated with:

MapBpw = ((2MapAdc * 200) / 256) + 8 + CRY

The 1bar MAP BPW term is calulated with:

MapBpw = ((1MapAdc * 189) / 256) + 21 + CRY

BobR.


Programmer wrote:

> Wouldn't mind seeing that one myself !
>
> Lyndon.
> ----- Original Message -----
> From: Daniel <bossute at iprimus.com.au>
> To: <gmecm at diy-efi.org>
> Sent: Saturday, July 14, 2001 5:49 AM
> Subject: Re: '749 questions
>
> > Chris any chance of a look at your bin , I want to check out how they are
> > getting around the barometric pressure check on start-up and WOT.
> >
> > Daniel Collins
> >
> > ----- Original Message -----
> > From: "Chris Rogers" <chrroger at hypermax.net.au>
> > To: <gmecm at diy-efi.org>
> > Sent: Saturday, July 14, 2001 6:10 PM
> > Subject: Re: '749 questions
> >
> >
> > > it will scale to a 2 bar item. that's what I have right now. resolution
> is
> > > reduced . 3 bar it will do but by extrapolation only ( beyond 2 bar)
> > > ----- Original Message -----
> > > From: "Programmer" <nwester at eidnet.org>
> > > To: <gmecm at diy-efi.org>
> > > Sent: Saturday, July 14, 2001 7:15 AM
> > > Subject: Re: '749 questions
> > >
> > >
> > > > Bruce was kind enough to sell me a couple cheaply--I've seen them as
> > > > low as $7.95 at a U-Pull-it yard. Sometimes you can bluff the sales
> > > > person at the counter on the other parts--just play stupid and you'd
> be
> > > > surprised at the prices. Since the '808 is MAP related--does anyone
> > > > know if it'd scale to a 2 or 3 bar MAP sensor ? Otherwise, with the
> > > > schematics--it's a pretty straight forward swap with the 1227749 ecm.
> > > >
> > > > BTW--There's a guy in Calgary, AB runnin' a 780cc Rotax in a dragster
> > > > that's running low 10 second quarters (normally aspirated).
> > > >
> > > > Lyndon.
> > > > ----- Original Message -----
> > > > From: Chris Rogers <chrroger at hypermax.net.au>
> > > > To: <gmecm at diy-efi.org>
> > > > Sent: Friday, July 13, 2001 2:21 PM
> > > > Subject: '749 questions
> > > >
> > > >
> > > > > out of curiosity ( and yes I am a newbie) what are these units worth
> > > > > used. I like the idea of what you have done with the fiero and have
> a
> > > > > similar project on the go except mine
> > > > > is blown and is a 550cc subaru engine. I am currently using the '808
> > > > > (australian version of the '165) and want to control boost with the
> > ECU
> > > > > instead of mechanically. gearbox is a 5sp manual final gearing is
> > 4.44.
> > > > car
> > > > > weighs 1300 lbs dry. I currently have everything (bar injectors)
> from
> > > the
> > > > > original '808  system including the knock sensor board.
> > > > >
> > > > > thanks
> > > > > chris rogers
> > > > > brisbane Australia.
> > > > >
> > > > >
> > > > >
> > > > >
> > > > > ----- Original Message -----
> > > > > From: "Programmer" <nwester at eidnet.org>
> > > > > To: <gmecm at diy-efi.org>
> > > > > Sent: Saturday, July 14, 2001 1:03 AM
> > > > > Subject: Re: '749 in Fiero
> > > > >
> > > > >
> > > > > > I'd better clarify a few things--I was the chip writer, info
> hander,
> > > > > > etc...the customer
> > > > > > did his own wiring and such. I'm on the 4th chip with him now. As
> > far
> > > as
> > > > I
> > > > > > know, he's
> > > > > > using a lot of the parts from a 2.0L Sunbird--but I'll nail him on
> > > > exactly
> > > > > > what he did. Yes,
> > > > > > it's dissy equipped.
> > > > > >
> > > > > > Lyndon.
> > > > > > ----- Original Message -----
> > > > > > From: <ECMnut at aol.com>
> > > > > > To: <gmecm at diy-efi.org>
> > > > > > Sent: Thursday, July 12, 2001 9:05 PM
> > > > > > Subject: Re: '749 in Fiero
> > > > > >
> > > > > >
> > > > > > > Nice work Lyndon!
> > > > > > >  I just got a 749 out of a 88 turbo GrandAm.
> > > > > > > Just itching to follow in your footstep with a boosted 4 banger.
> > > > > > > Are you running a distributor? (sorry if it's a repeat
> question).
> > > > > > > If you say "coil pak", my questions are just getting started..
> > > <grin>
> > > > > > > Mike V
> > > > > > >
> > > > > > > In a message dated 7/12/01 10:06:42 AM Eastern Daylight Time,
> > > > > > > nwester at eidnet.org writes:
> > > > > > >
> > > > > > > > Guys--just wanted to report that a '749 project in a turbo'd
> > Fiero
> > > > is
> > > > > > > >  working good. We've got boost limited to 10 psi, idle is
> still
> > a
> > > > bit
> > > > > > weird,
> > > > > > > >  but otherwise it's using the basic syty bin with the injector
> > > > > constant
> > > > > > > >  changed. Manual trans with 2.8 V6...
> > > > > > > >  Apparently ran a 14.89 yesterday at the track with no further
> > > > tweaks.
> > > > > > > >  I'll have a full report of all mods later...
> > > > > > > >
> > > > > > > >  Lyndon.
> > > > > > > >
> > > > > >
> > > > >

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