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Re: ECM calibrations for upgraded Xfire



> I have actually done some of the things you've described. The TBI units
are
> 2" with stock injectors.

Stock for what application?.

 The Extrude Hone process increased air capacity by
> 30% along with port matching the intake and exhaust manifolds.

And which manifold did you start with,
The shared runner version, or the isolated?

 All emissions
> is operational.
>  The TFS heads have 195cc intake runners, aluminum and 64cc chambers with
> angled plugs. I figure compression ratio went from 9.0 to 10-10.5. The cam
> is a retrofit hyd. roller with full roller rockers. Ignition is using
Accel
> Supercoil and MSD6A. I went to the drags and also put vehicle on dyno with
> the stock chip from Turbo City. I believe the knock sensor was retarding
> timing and inspecting the plugs later showed they were running lean.
Exhaust
> is stock with Random Tech cat/Flowmasters/ and DynoMax Y-pipe. They have
> since sent me a new chip which fattened up fuel curve and bumped initial
> advance and lowered total advance. It seems to be running well although I
> believe it is still a little rich at startup idle and at a steady cruise.
I
> don' think WOT operation is very far off but I am thinking of renting
Diacom
> + software to really tell. What mods had you done to yours? Can you give
me
> any clue as to timing and fuel curves you had used?

2"ers
95 lb hr injectors
Remote fuel pressure regulators, one vacuum referenced, TB plumbed in
pararel not series
Nor EGR tunnel.
!/4" lid spacer to increase plenumm volume.
Cut back runner roofs 5/8".
Different IAC Pintles (custom)
Different air filters.

Differences in vehicles has a tremendous influence in the tuning, and I can
quarantee you you'd be better off starting with something close, as you have
then what I had.
Bruce


>
> Thanks,
>
> Dominic
>
>
> Original Message -----
> From: "Bruce Plecan" <nacelp@bright.net>
> To: <gmecm@diy-efi.org>
> Sent: Wednesday, August 09, 2000 10:14 PM
> Subject: Re: ECM calibrations for upgraded Xfire
>
>
> >
> > Nope, was years ago.
> > The info available now, makes my early stuff look premitive.
> > If you care to spend the time, you can do a great chip for that car.
> > Will take more then a chip to get the full performance out of your set
up.
> > You'll need to do 2" butterflies, remove the egr tunnel, increase the
> plenum
> > volume, different injectors, to get it's full potential.
> > Grumpy
> >
> >
> >
> >
> > > I have posted using plain text. Do you have a bin file of the one u
used
> > for
> > > the 13.7 time?
> > > Thanks,
> > > Dominic
> >
> > > From: Bruce Plecan
> > > Turn off that awful script / coloring.
> > > I've run a 13.7 with a cross fire.
> > > Try reading tuning docs (at the FTP), and programming 101.
> > > For a combo like that, you'll need to do your own chip, and just start
> > with
> > > a stock one or what ever ya bought from them.
> > > Some major (yet non critical) intake porting needs done
> > > Grumpy
> >
> > > From: Dominic Sorresso
> > > I am new to your forum but it was strongly suggested by a member of
the
> > > Xfire forum that I join.
> > > I recently "upgraded" my 84 Vette Xfire with a Comp Cam hyd roller
> 211/218
> > > degree with .488/495 lift at 112 degree lobe separation. I also
upgraded
> > the
> > > heads to the new
> > > Trick Flow 23 degree aluminum heads. Also have upgraded ECM and TBI
> units
> > to
> > > Turbo City
> > > systems ie 7747 ECM. I also have Extrude Honed manifold. On a 95
degree
> > day,
> > > car ran a 14.3 at 99.7mph and pulled 253 hp@4600rpm/307 lbft@4200rpm
at
> > the
> > > rear wheels on chassis dyno. This was with stock configuration chip. I
> am
> > > interested in knowing if anyone has a bin file for a combination
similar
> > to
> > > this. I don't doubt that knock Sensor was causing  retard of timing
> since
> > > power went south after 4600rpm. I have a Needhams EMP-10 burner  and
> would
> > > be interested in mainly suggested fuel and timing calibrations. I
> believe
> > it
> > > is running slightly rich especially at cold idle strartup and would
also
> > > like to address dis/engagement of 4+3 OD unit at higher speeds.
> >
> >
>
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