[Gmecm] 749 ECM

Wed Mar 14 13:27:27 UTC 2007

Hello James

I've run $58 on a 32K (29AT256)flash prom without
issues.  Just load the bin file into the upper half of
the prom. (start bin @ $4000)

I ran a 305 with twin Eaton M90 blowers with a
modified 7749 (FETs upgraded for use with 8 low Z, 35
lb injectors) at 15 lbs boost.

There is a ton of info about my setup on Thirdgen.org,
search for SATURN5, in the DIY Prom section.

I'll try to remember when I get home from work to look
for one of my old bin files.

Cheers, Bob
--- James Panter <9jim30 at charter.net> wrote:

> I was looking at some of my very early communication
> on the whole subject of 
> the 749 ECM and the Proms used in it.   One fellow
> was quite insistant that 
> the right Prom to use was not the BBZB as used in
> the Sy/Ty but that the 
> proper one would be the 90-92 Firebird Prom with the
> $58 installed in it. 
> Can someone who has actually perfected the tune for
> a Turbocharged V8 
> respond with what Prom they  used?  I'm working on
> utilizing the BBZB and if 
> it can't be perfected for a V8, I want to stop
> wasting my time.  What are 
> the issues inherent in this issue and what are the
> pros and cons?    Thanks
> Jim
> ----- Original Message ----- 
> From: <davesnothereman at netscape.net>
> To: <gmecm at diy-efi.org>
> Sent: Wednesday, March 14, 2007 6:12 AM
> Subject: Re: [Gmecm] 749 ECM
> 
> 
> > Yes, you need to adjust the BPW vs Desired EGR
> table to affect fuel 
> > delivery.  The 0% EGR entry is the main cell.  It
> may help to set egr 
> > enable temp to it's maximum during initial stages
> of tuning.
> >
> > The $58 calibration spark values come from the
> lowest RPM row of the main 
> > spark table when the throttle is closed. 
> Sometimes this can cause issues.
> >
> > Idle can be tricky in $58.  It helps to isolate
> closed loop issues from 
> > open loop issues by setting closed loop enable
> temp very high.  It's often 
> > easier to make the engine idle well in open loop,
> especially if you have a 
> > bit of a cam.  O2 parameters can be important as
> the ecm will calculate 
> > the time required for the O2 signal to get back to
> the ecm.
> >
> > You can also force the ecm rich or lean in closed
> loop to see what 
> > happens.
> >
> > Zaphod
> >
> > -----Original Message-----
> > From: romans at starstream.net
> > To: gmecm at diy-efi.org
> > Sent: Tue, 13 Mar 2007 12:29 AM
> > Subject: Re: [Gmecm] 749 ECM
> >
> >
> > I don't know where the injector constant is on a
> 4.3 Turbo $58 file, I 
> > remember it has something to do with the
> > EGR... BPC vs EGR?
> >
> > The two tables I'm referring to are the VE Table -
> in idle
> > and VE Table - not in idle.
> >
> > Since you say you are idling for 3 minutes before
> it dies, it would 
> > indicate to me that it's too rich, but when it
> goes
> > into close loop it does something bad.
> >
> > You need to scan it to see what it's doing.. The
> VE Table, - in idle goes 
> > from 20 kpa to 100 kpa and from 600 RPM's to 1600.
> > The 600 rpm and 20 kpa setting is 28.08. If it's
> idling at 50 kpa due to 
> > your cam and 600 rpm's, the be at 50kpa is set at
> 36.66
> > You need to reduce this number to match up with
> what fuel it needs, smooth 
> > the map.... Run it on as many cells as possible
> and keep
> > going until the corrections are very small, try to
> keep it pulling out 
> > about 5% fuel.
> > Mark
> > ----- Original Message ----- From: "James Panter"
> <9jim30 at charter.net>
> > To: <gmecm at diy-efi.org>
> > Sent: Monday, March 12, 2007 3:28 PM
> > Subject: Re: [Gmecm] 749 ECM
> >
> >> Mark: I have the injector set at 7 for 42 lb
> injectors which should be > 
> >> correct. The engine dies within two or three
> minutes after starting > 
> >> which, I believe, is due to the rich condition.
> That constant was about > 
> >> 4.5 before so the new consant may help.
> >> What line items are you referring to on the VE
> tables? The only line item 
> >>  > that I see with VE and closed throttle is F30.
> >> Your help and suggestions are greatly
> appreciated/
> >> Jim Panter
> >> ----- Original Message ----- > From: "Mark
> Romans" 
> >> <romans at starstream.net>
> >> To: <gmecm at diy-efi.org>
> >> Sent: Monday, March 12, 2007 9:43 AM
> >> Subject: Re: [Gmecm] 749 ECM
> >>
> >>
> >>> Hi Jim: First make sure that your injector
> constant is set properly.
> >>> 2nd. A stock engine idles at about 35kpa, so
> what kpa does your engine 
> >>>  >> idle at?
> >>> Past the VE setting from 35 kpa to the kpa your
> engine idles at. Copy >> 
> >>> that kpa from the
> >>> colume where it idles all the way to the
> smallest kpa settings on the >> 
> >>> map. (Closed Throttle).
> >>> This will get you started.
> >>> Mark
> >>> ----- Original Message ----- >> From: "James
> Panter" 
> >>> <9jim30 at charter.net>
> >>> To: <gmecm at diy-efi.org>
> >>> Sent: Monday, March 12, 2007 6:22 AM
> >>> Subject: Re: [Gmecm] 749 ECM
> >>>
> >>>
> >>>> Mike: Good point you make particularly on the
> injectors. I doubt >>> 
> >>>> whether the small block is a 350 or 355 would
> make much difference in 
> >>>>  >>> the larger picture (a stroker would). I'm
> using a very mild Isky 
> >>>> cam >>> and 45 lb injectors and was just really
> surprised at how rich 
> >>>> the engine >>> is intially after just changing
> the bin to reflect a V8 
> >>>> rather than the >>> V6 because the actually cyl
> volume is very similar. 
> >>>> And, yes I have an >>> LM1 and all the Moates
> stuff. I was just hoping 
> >>>> to get close on the >>> settings and save time.
> The car hasn't been 
> >>>> driven yet, just started >>> and it's far too
> rich to drive.
> >>>> I appreciate you response.
> >>>> Jim
> >>>> ----- Original Message ----- >>> From: "Mike V"
> <efi at dyakron.com>
> >>>> To: <gmecm at diy-efi.org>
> >>>> Sent: Monday, March 12, 2007 7:48 AM
> >>>> Subject: Re: [Gmecm] 749 ECM
> >>>>
> >>>>
> >>>>> Hi Jim,
> >>>>> it's unlikely that there will be a bin that is
> ready made for your 
> >>>>>  >>>> combination of
> >>>>> cam, injectors, etc. Do you have a log file
> from your ALDL >>>> 
> >>>>> datastream?
> >>>>> Also, what are the specifics of the engine?
> There are other factors, 
> >>>>>  >>>> but
> >>>>> the camshaft specs and injector size are two
> big ones that come to 
> >>>>>  >>>> mind.
> >>>>> Datastream monitoring is critical for
> addressing this sort of thing.
> >>>>> mv
> >>>>>
> >>>>> ----- Original Message ----- >>>> From: "James
> Panter" 
> >>>>> <9jim30 at charter.net>
> >>>>> To: <gmecm at diy-efi.org>
> >>>>> Sent: Sunday, March 11, 2007 7:34 PM
> >>>>> Subject: [Gmecm] 749 ECM
> >>>>>
> >>>>>
> >>>>>> Hey Guys Is there anyone who has done a small
> block Chev (twin >>>>> 
> >>>>>> turbos @ 8 psi boost) using the $58 program
> that has it tuned?? I 
> >>>>>>  >>>>> have my project running but very rick
> and was hoping to find 
> >>>>>> someone >>>>> who could send me a corrected
> bin or give me line items 
> >>>>>> changes they >>>>> made that worked.
> >>>>>> Thanks for any help--- 
> >>>>>> Jim
> 
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