DIY_EFI Digest V5 #48

[Glen Beard]

> Date: Tue, 1 Feb 2000 00:44:28 -0500
> From: "nacelp" <nacelp at bright.net>
> Subject: Re: New member, programming under boost questions
> >
> > My first goal, under the heading of "learn on the old motor first", is to
> > eliminate the FMU and alter the spark tables to be better suited to the
> > blown application.
> 
> I don't see the logic in eliminating the FMU.  It's the only thing raising
> your fuel
> capacity.

The FMU is very inconsistent when it comes to increasing the fuel
pressure in relation to boost.  It's not even a proportional
rising rate.  On one run it might have A/F right on while the
next run it's way off.  This device has already cost me an
expensive rebuild because I leaned out at WOT.

It's not the only thing raising fuel capacity.  The goal here is
to install larger injectors, set the fuel pressure back down
where the injectors are rated for and calibrate the PCM for max
power.  Currently I run about 95# fuel pressure through my stock
24# injectors at 6# boost.  The problem comes in where, as you
stated, the LT1 has no provisions for boost.  The question is how
to accomplish this using the existing PCM programming while
altering the EEPROM tables using the recently written LT1 Editor
program.

Dave has written to me asking the same questions.  He wants to
know if there is a way to help the PCM accommodate boost.  Short
of a completely different program, I think we are stuck on
fooling it into thinking 14.7psia (1 bar) is actually 6# or 10#
boost.  As far as I know there is no way to get the PCM to
properly use a 2 bar MAP.  Am I wrong here?  With enough changing
tables could you get the PCM to work correctly using a 2 bar MAP?

-- 
Glen Beard  95 T/A conv M6
355, Vortech, heads, cam...
http://home.nycap.rr.com/gbeard1/TransAm.html
----------------------------------------------------------------------------
To unsubscribe from diy_efi, send "unsubscribe diy_efi" (without the quotes)
in the body of a message (not the subject) to majordomo at lists.diy-efi.org