Cam tuning

Douglas Ratcliffe dratclif at mail.ucf.edu
Tue Mar 21 01:04:58 GMT 2000


So let me get this straight... in one sentence you say aftermarket computers are MAP, and GN guys use LT1/LS1 MAFs in place of the MAP system?

So where does that put me?  I have no MAF, and would rather stay MAP, but I have no idea how to convert the computer to use a 3-bar MAP.  Is it possible to just change a "MAP resolution table" in the computer, or is it all hard coded?

Thanks,

Doug R - Black 93Z A4 3.73 - D.B. F-Body Organizer
Mods: DragRadials,Hooker 1.75" headers,Flowmaster,AS&M CAI
Mods: 3.73 gears, SLP Torsen, S&S Stage 1 heads, UD pulleys,
Mods: Chip,EibachSprings,1LEswaybars, AFPR - 13.11 at 105.5
*My car: http://daytona.f-body.org/doug

>>> fredericksk at worldnet.att.net 03/20/00 07:48PM >>>
We use a MAF for all ECM airflow inputs.  There is a 2 bar MAP present, but
just to run the silly little boost gauge on the dash.  When people convert
to DFI or SpeedPro and keep the GM harness with a jumper harness for the new
ECM, they generally run the 3 bar MAP signal in the old MAF input signal
wire.

On most hopped up GNs, the MAF is maxed out after 15 psi of boost or so, and
any additional fuel enrichment is 'guessed at' in the PE enrichment tables.
A recent upgrade for these ECMs is a 8051 based Translator designed by Bob
Bailey that allows use of a wider range LT1/LS1 MAF and "translates" its'
signal.  With an appropriate chip the ECM can read up to 512 GPS, instead of
the old 255, allowing better intermediate boost tuning.


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