Re: Turbo V6 Tuniing continued

[Barry Tisdale <btisdale@cybersol.com>]

Excellent work, Jeff!

I'm following this thread anxiously, as I'll be doing the same w/ a Sy -
Vortec heads, cam, 40# injectors (up from 30#) and bigger turbo.  I'm a
newbie @ chipping, but am learning a lot and have a pretty good prog on the
old setup.  Waiting for all the parts to arrive so's I can reassemble the
beast & get back on the road.

Regarding the knock retard; *removing* it from the ECU program (or
disconnecting KS) sounds dangerous to me (ala Kenny Bell's chip) - *but* -
something to try, if the ECU tables will permit it:  Decay it out *real*
fast.  One knock event will take about 2 seconds to completely decay out
the retard, meanwhile you're through the critical RPM/boost range where it
was needed, probably in the next gear.  If you *are* getting knock retard,
this can be good for some very nice acceleration improvements - I cut 0.5
secs off my 0-60 times by setting the decay to 10x normal rate.  You'll
still have the benefit of the KS retarding when needed, but just for an
instant, then its back to normal.  I'm looking for almost constant knock
retard, but in the 2° range or so - then, you know you're real close to
optimal, and can change the timing tables accordingly.

As a side note, after installing the cam & modified distributor (moved
clamping boss), I was getting false knock retard @ 2000 RPMs of up to 18°.
Moved the KS to the front of the engine (where the KS for the MSD unit was)
and its ok now.  Checked the knock indication w/ a stethoscope.  Re-hooked
up the rear, stock KS recently (after maybe 500 miles on the new stuff),
and false knock @ 2000 is now down to 4° or so.  I assume a thousand or so
more miles, whatever's causing it will be worn in even more, and it may be
gone.  Then, I'll re-hook up the original KS.  BTW, the SyTy KS has a 3.9k
internal parallel resistor, so the ECU knows its not there; can't just
unhook it w/o throwing a code (checks for open or short).

I'm also using an MSD 6a box w/ MSD's adjustable timing control - makes
timing adjustments quicker & easier than doing chip changes here; can go
+/- 8°.  Now, if there were just a way of doing the same thing w/ injector
'on' time........  Time for an emulator.......

BTW, don't let Grumpy find out that you're relying on stock oxy sensor for
fuel values............}:}E

Keep it up & let us (me) know how it goes - Barry
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